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100 Cards in this Set
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ch41
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Describe where and in what form the human body stores excess energy-rich molecules, the two hormones that regulate storage and use of glucose, and the homeostatic regulation of glucose levels (figure 41.20 – very important)
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The first sites used for energy storage are liver and muscle cells. Excess energy from the diet is stored in glycogen - the body usually expends liver glycogen first and then muscle glycogen and fat. The two hormones that regulate storage and use of glucose are glucagon and insulin
Blood glucose is at a homeostasis from 70-110 mg. When blood glucose levels rise the pancreas secretes insulin into the blood, enhancing glucose transport into body cells and glucose is then stored as glycogen, dropping levels. When blood glucose levels drop the pancreas secretes glucagon into the blood, promoting the breakdown of glycogen and then the release of glucose into the blood, raising levels. |
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Know the role of the hepatic portal vein in the digestive system, and the processing of nutrients and drugs that occurs in the liver.
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The liver is a key site for glucose homeostasis… when insulin levels rise after a carbohydrate rich meal, glucose entering the liver in the hepatic portal vein is used to synthesize glycogen. When blood in the hepatic portal vein has a much lower glucose concentration, glucagon stimulates the liver to break down glycogen releasing glycogen into the blood. The liver processes glucagon and glycogen into alternating things so that when the blood maintains its glucose levels. The liver processes glucagon and insulin.
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Know where and how the major types of macromolecules (proteins, carbohydrates, lipids, nucleic acids) are digested and absorbed within the mammalian digestive system. (Figure 41.12 – know this!!)
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-Carbohydrates are digested in the oral cavity, stomach, small intestine (with enzymes from either the pancreas or epithelium. They are broken down by salivary amylase in the mouth to small polysaccharides and then by pancreatic amylase to disaccharides and then disaccharidases complete the process to monosaccharides.
-Proteins are broken down starting in the stomach and then to the small intestine (with enzymes from the pancreas or epithelium). Pepsin breaks them down in the stomach and then trypsin breaks them down to smaller polypeptides where depeptidase complete the break down to amino acids. -Lipids are only broken down in the small intestine with enzymes from only the pancreas. Pancreatic lipase breaks fat into glycerol and fatty acids. -Nucleic acids are broken down in the small intestine with enzymes from both the pancreas and the epithelium. DNA and RNA can be broken down by pancreatic nucleases to nucleotides and then by nucleotidases to nitrogenous bases. |
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Describe the different types of chemical digestion that occur in the mouth, stomach, and small intestine, the enzymes involved in chemical digestion, their source, their substrates, and their products. (Figure 41.12 – very important)
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Salivia intiates chemical digestion while also protecting the mouth from acidic breakdown. In the stomach gastric juice carries out chemical digestion. HCL – disrupts the extracellular matrix that binds cells together (this lowers gastric juice pH) which denatures proteins in food. A protease or protein digesting enzyme called pepsin works best in a strongly acidic environment. Most chemical digestion occurs in the small intestine with all the villi for absorption and all the chemicals that can be found for break down.
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Describe the roles of the liver and gall bladder in digestion – know what is secreted from each and the function of the secretions.
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The liver filters nutrient rich and toxin rich blood from intestines because the blood is not only enriched with monomers and nutrients, but also small and harmful molecules. The liver has hepatic portal veins to carry blood from the intestine to the liver whose cells – naturally neutralize toxins, -break down.metabolize drugs, - remove glucose from blood when necessary.
The gallbladder stores and concentrates bile. Bile contains bile salts, which act as emulsifiers or detergents that aid in digestion and absorption of lipids specifically. Bile is integral to the livers destruction of red blood cells that are no longer fully functional. |
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Describe the role of the pancreas in digestion and the function of its secretions.
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The pancreas secretes insulin and glucagon, which respectively allow the body to take in glucose and break down glycogen to release glucose into the blood. The pancreas maintains the homeostasis of blood glucose levels, which is essential. If you can’t make insulin, sugar stays in the blood and damages organs and tissues. It keeps all your organs in tact by maintaining this specific part of a person.
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Explain how the small intestine is specialized for digestion and absorption. Know the difference between villi and microvilli. Know the enzymes secrete by the small intestine, their substrates, and their products (Figure 41.13, 41.12).
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The small intestine is a highly folded surface with large folds encircling it and it is studded with finger like projections called villi that each have many microscopic projections or microvilli exposed to the intestinal lumen. All these folds provide an enormous surface area that make absorption so easily attainable. The small intestine secretes enzymes from the pancreas:
- pancreatic amylase (breaks down polysaccharides to disaccharides) - pancreatic trypsin (polypeptides to smaller ones) and pancreatic carboxypeptidase (polypeptides to peptides) - pancreatic nucleases (breaks down DNA, RNA to nucleotides) - pancreatic lipase (breaks down fat to glycerol/fatty acids) and from the epithelium: - disaccharidase (disaccharides to monosaccharides) - dipeptidase, peptidase (small peptides to amino acids) - nucleotidases (nucleotides to nucleosides) - nucleosidases (nucleosides to nitrogenous bases) |
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ch42
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Distinguish between pulmonary and systemic circuits and explain the functions of each. Know what is meant by ‘double circulation.’ (Figure 42.5)
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A pulmonary circuit moves the blood from the heart to the lungs and the systemic circuit extends to your entire body so it can get blood (it requires more muscle.
Double circulation is the arrangement of having two circuits, the pumps for the two circuits are combined into a single organ. |
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Know the names of the heart chambers and major blood vessels lead to and from the heart, and the status of blood oxygenation in each vessel and chamber. Trace the path of blood flow in the human cardiovascular system (Figure 42.6).
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Atrium are the upper chambers that receive blood and ventricles are the lower chambers that eject it. Arteries carry blood away from the heart and veins carry blood to the heart.
Blood flows specifically from the Heart: right ventricle to pulmonary arteries to capillaries to pulmonary vein to left atrium to left ventricle to aorta to capillaries to superior vena cava/inferior vena cava to right atrium. Less specifically it is Heart, pulmonary circuit (lungs), heart, systemic circuit (body), heart. |
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Define a cardiac cycle, distinguish between systole and diastole, and explain what causes the first and second heart sounds (Figure 42.8). Be able to define cardiac output and stroke volume.
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The cardiac cycle is the sequence of pumping and filing the heart and body with blood.
Systole is the contraction of the pumping phase and diastole is the relaxation or filling phase. The sounds of the heart beat are the sounds of valves closing: the recoil of blood against the AV valves is the “lub” and the recoil of blood against semilunar valves is the “dub”. Cardiac output is a measure of the blood flow out of the left ventricle (most important and most muscley heart chamber). Stroke volume is the amount of blood pumped by a ventricle in a single contraction. |
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List the heart valves in a human heart, describe their location, and explain their functions. (Figure 42.7)
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The Atrioventricular (AV) Valves lie between each atrium and ventricle. There are two. The pressure from the ventricle closes them and they function to move blood between chambers.
The semilunar valves are at the two exits of the heart: -the aorta leaving the left ventricle and –the pulmonary artery leaving the right ventricle. The blood pressure buildup in the aorta closes these valves and they function to prevent backflow. |
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(You do not need to know the proteins involved in blood clotting).(Figure 42.18)
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Platelets are not cells but shredded cells and cell fragments from megakaryocytes. They travel in blood, looking for somewhere to stick and activate. They are able to clot your blood
-If they get stuck to connective tissue or collagen they will activate and begin spinning fibrous (a web like protein) and start catching cells. -A platelet knows a blood vessel is broken when the collagen protein in connective tissue is wrapped outside. Collagen is a rubbery protein that holds things together. |
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Explain how muscle movements in humans ventilate the lungs, and what is meant by ‘negative pressure’ breathing.(Figure 42.28)
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For inhalation the diaphragm contracts, moving it down. The rib cage expands as rib muscles contract. And for Exhalation the diaphragm relaxes, moving it up. The rib cage gets smaller as rib muscles relax.
Negative pressure breathing is pulling rather than pushing air into their lungs. They use muscle contraction to actively expand the thoracic cavity. |
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Explain how breathing is controlled in humans, how changes in blood CO2 affect the pH of specific fluids in the body, and how this affects breathing (Figure 42.29)
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High levels of carbon dioxide and hydrogen cause a change in blood pH as well as cerebrospinal fluid pH. (so breathe faster).
Blood pH homeostasis occurs and the set point is 7.4 so if you try to hold your breath then the blood CO2 levels go up and blood gets more acidic. If CO2 increases then pH will lower and the medulla oblongata causes rib muscles and diaphragm to increase rate and depth of ventilation dropping CO2 lvels. |
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ch 43
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Describe the inflammatory response, including the four characteristics of inflammation (rubor, tumor, calor, dolor), how inflammation is triggered, and how it affects blood vessels of the infected tissue, the effect on neutrophils. (Everything in Figure 43.8 – important!)
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If there is an infection or tissue damage inflammation will occur bringing immune cells to attach the cells. Inflammation recruits immune cells to infected tissues, destroys pathogens, heals tissue, flushes site out, helps healing.
It is characterized by: dolor-pain, tumor-swelling, rubor-redness, calor-heat. Inflammation is triggered by mast cells that trigger pathogens, They send out histamine to the blood vessels causing vasodilation, which increases permeability and helps swelling. Neutrophils are pulled out of the blood stream and digest pathogens so the tissue can heal. image on study guide |
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For B cells, describe how plasma cells help combat an infection. (Figure 43.18)
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B cells are born and “trained” in the bone marrow and patrol lymphocytes and lymph nodes searching for things that do not belong. B cells look for an antigen that binds their BCR and if a match is found the B Cell clones itself using mitosis.
Effector cells are a plasma cell for B cells that secrete antigens so antibodies then go into the blood lymph and attack or neutralize virus’ |
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For T cells, distinguish between the function of effector cells (cytotoxic T cells) and memory cells, and when each are produced after exposure to antigen. Describe how cytotoxic T cells help combat an infection. (Figure 43.17)
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Effector cells are short lived, activated cytotoxic T cells that enter the infected or inflamed tissues looking to kill infected cells.
Cells that aren’t activated are memory T cells made by differentiation and they are used if the virus comes back. They live forever and are able to immediately take care of a virus. |
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ch44
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Describe why animals eliminate nitrogenous wastes, and the source of nitrogenous waste. (Figure 44.8)
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Animals eliminate nitrogenous wastes because they are the cells chemical waste, which is amino groups from proteins and nucleic acids that get converted to ammonia.
Nitrogenous waste comes from various methods in various species: -fish: diffuse across cells and it dissolves in water -birds, reptiles: convert ammonia to less toxic uric acid (white paste) -mammals: convert ammonia to less toxic urea which is safer to store and transport in blood, the liver (detoxifying organ) converts ammonia and CO2 to urea. |
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Know the chemical properties of ammonia and urea. Know where, how, and why urea is made in the body.(Figure 44.8)
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Ammonia is the nitrogen removed by enzymes from proteins and nucleic acids that are being broken apart. Ammonia is very toxic because its ion (NH4+) interferes with oxidative phosphorylation.
Urea is a nitrogenous waste produced in the liver. It combines ammonia with carbon dioxide, it has a very low toxicity which is important to allow transfer through the circulatory system. |
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Know the role of the liver in disposal of nitrogenous wastes.
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The liver is the detoxifying organ that converts ammonia to urea so that it can move through the circulatory system.
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Describe the four key steps in the process of excretion and urine production (filtration, reabsorption, secretion, and excretion) in the human kidney. (Figure 44.10).
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The nephron makes blood become filtrate and then become urine in 4 key steps:
1. Filtration – pressure filtering of body fluids, produces filtrate (not urine) 2. Reabsorbtion – some things move back into the body’s blood, giving back solutes 3. Secretion – other things get moved out of the blood into filtrate like toxins and drugs 4. Excretion - removing the filtrate from the system and urination occurs |
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Know the composition of filtrate, how filtrate is formed, and what molecules are (or are not) normally found in the filtrate (and why). (Figure 44.15)
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Filtrate is anything smaller than a protein: H2O, NaCl, glucose, amino acids, H+, HCO3-, drugs… These things are small enough to cross the membrane of the excretory tubule and form this solution.
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Explain how blood osmolarity homeostasis is regulated by the hormone ADH (anti-diuretic hormone, also known as vasopressin). Know where ADH is produced, why/when it is released, what parts of the nephron it targets, and how ADH functions at a cellular level (Figure 44.19, 44.20)
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Kidneys regulate blood osmolarity homeostasis…water reabsorbtion can be controlled it is stimulated by sweating, dehydration, high salt intake and overly concentrated blood. This in turn causes the hypothalamus to be sensored/notified, the hypothalamus sends a respone….
It tells the pituitary gland to release the Antidiuretic hormone (ADH) (vasosuppressin). ADH is produced in the hypothalamus and stored in the posterior pituitary gland. ADH targets the collecting duct in the kidney, it creates more reabsorbtion of H2O and less urine output. ADH makes aquaporins, More specifically: ADH binds to a membrane receptor on the collecting duct membrane and the receptor activate cAMP a secondary messenger system, vesicles with aquaporin water channels are inserted into membrane lining lumen of the collecting duct, aquaporin channels enhance reabsorption of water from collecting duct into interstitial fluid. |
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Define aquaporins, know their function, and know where they are found (and are not found) in nephron. (Figure 44.15)
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Aquaporin’s are water channels that get inserted into the membrane lining lumen of the collecting duct. They are found on vesicles inside collecting duct cells that merge with the membrane. They allow better reabsorption of water from the collecting duct (to interstitial fluid) so blood osmolarity is maintained.
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Know what a diuretics is, and how diuretics and alcohol affect the excretory system, and their mechanism of action.
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A diuretic increases urine production and output so that you pee more. Alcohol affects the release of ADH by causing increased urine output. It tells the hypothalamus not to release ADH that is why you can get dehydrated very easily.
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ch45
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Distinguish between endocrine glands and exocrine glands.
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Endocrine glands are made of endocrine cells that secrete hormones into the blood stream. Exocrine glands secrete hormones and release them into a duct. (Salivary glands are exocrine glands)
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Distinguish between alpha and beta cells in the pancreas and explain how their antagonistic hormones (insulin and glucagon) regulate blood glucose homeostasis. (Figure 45.13)
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These are endocrine cells. Beta cells secrete insulin all over the body and Alpha cells secrete glucagon to the liver only. Insulin and glucagon are antagonistic, meaning they counteract each other. They regulate glucose homeostasis by negative feedback, they use the method of triggering the cells when there is a deficiency in glucose where glucagon can make more and insulin can suppress.
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Describe the function of the thyroid gland and the thyroid hormone. Describe the causes, symptoms, and treatment of hypothyroidism and hyperthyroidism.
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The thyroid gland functions to maintain metabolism, growth and development, blood pressure, heart rate and more. It is found in the neck wrapped around the esophagus.
-This endocrine gland secretes a hormone called the thyroid hormone, which is a lipid soluble, amine. It contains iodine, which targets almost the whole body and makes cells work harder. -Underproduction of the thyroid hormone is hypothyroidism. This means levels are too low (caused by malnutrition or getting old and appears to be hereditary. Leads to stunted growth, mental impairment, weight gain, lethargy. Can be treated by a drug (#5 most prescribed in the country) -Overproduction of the thyroid hormone is hyperthyroidism. It is aka graves disease. The high metabolism, high body temp., weight loss and insomnia. It is caused usually by a thyroid tumor. Can be cut out or you can take pills to inhibit. |
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Know the role of a mineral in the function of the thyroid, where that mineral comes from in our diets, and what happens when this mineral is lacking in the diet.
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In the function of the thyroid the mineral Iodine is essential. It is most naturally found in dried seaweed, but in our diets we usually find it in iodized table salt (most table salt is iodized). If this mineral is lacking it causes hypothyroidism, which causes weight gain, stunted growth, mental impairment. Etc.
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Know the negative feedback mechanism that regulates thyroid hormone, and how hormones from the hypothalamus and pituitary gland are involved. (Figure 45.17)
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stimulus - sensoy neuron: hypothalamus secretes thyrotropin releasing hormone (TRH) - cell secretes to blood vessel - stimulus anterior pituitary: secretes thyroid stimulating hormone (TSH) - secretes to blood vessel - stimulates thyroid gland to secrete thyroid hormones T3 and T4 - secretes blood vessel- target cells - a response
image |
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Know the functions and targets of the hormones released by the adrenal medulla, and what stimulates leads their release. (Figure 45.21)
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Adrenal medulla s the inner layer for short term stress response. Stressful stimuli cause the hypothalamus to activate the adrenal medulla via nerve impulses. It then secretes epinephrine and norepinephrine. Increase bp, breathing, metabolic rate, change blood flow.
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Know the functions and targets of the hormones released by the adrenal cortex, what stimulates their release, and why these hormones are sometimes used as drugs to treat patients. (Figure 45.17)
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The adrenal cortex is the outer layer that addresses long term stress. ACTH goes to the cortex (it is a tropic hormone that causes a hormone cascade). The cortex in turn releases corticosteroids (stress hormones 2 types)
-Glucocorticoids increase blood glucose and partially suppress immune system -Mineralcortecoids retain ions and water by kidneys and incres bp/bv They are sometimes used as drugs because they reduce inflammation but they are bad cause they suppress the immune system. |
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ch46
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start
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Describe the processes of fertilization and implantation, and where each normally occurs during a successful pregnancy.(Figure 46.15)
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During sexual intercourse fertilization occurs. This is when an egg cell will fuze with a sperm cell and form a new zygote cell. The zygote then undergoes cleavage and forms a ball of cells called a blastocyte which is implanted in the uterus.
Implantation is if the blastocyte is attached inside the uterus. Now the embryo must stop menstruation and maintain the endometrium with hCG. |
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Describe the functions and hormones release by the corpus luteum.
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The corpus luteum is what left over follicle cells turn into. They secrete new hormones and will shrink/disintegrate in 10 days if not pregnant.
The corpus luteum secretes estradiol as well as progesterone. Progesterone helps maintain the uterine lining during pregnancy and estradiol stops FSH and stimulates LH so this can occur. |
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Know the role of the hormone hCG, its source, its target, the response in its target. Know a clinical use for detecting hCG.
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hCG (human chronic gonadptropin) is from the embryo and targets the corpus luteum. It helps maintain estrogen and progesterone secretions. It maintains the endometrium and stops menstruation and ovulation. It appears in the urine of a pregnant women (explaining pregnancy test functioning).
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Explain how labor begins, the hormones involved in labor, their origins, targets, and results. Know a drug used to induce labor, and how it works. (Figure 46.18)
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Labor is a series of contractions of the uterus (smooth muscle tissue) that become stronger and more frequent. They use positive feedback to control muscle contraction (induce the release of more oxytocin and prostaglandins to keep up contractions.
Estradiol from the ovaries induces oxytocin receptors in the uterus smooth muscle cells. Oxytocin then stimulates the uterus to contract and the placenta to make prostaglandins. Prostaglandins stimulate contractions of the uterus, which triggers the release of more oxytocin. Labor can be induced by the drug Pitocin which is essentially a fake oxytocin so it’s a hormone as drug. |
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ch48
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Know the difference between active transport and passive transport, and the types of proteins involved in each. (Figure 7.18, 7.19 in chapter 7)
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Active transport uses a pump protein using ATP and flows from low to high concentration.
Passive transport uses an ion channel protein without ATP and solutes flow from high to low concentration. |
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Know the three different proteins and types of ions involved in producing an action potential and creating the resting potential.
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Voltage gated Na+ channels, voltage gated K+ channels, and sodium potassium pump. Sodium and potassium ions are involved. They allow the action potential to be built and the resting potential to be restored.
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Compare excitatory post-synaptic potentials and inhibitory post-synaptic potentials, what types of ions they allow to move across the membrane, and how that would change the membrane potential. (Figure 48.17)
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An EPSP has excitatory neurotransmitters that open the ligand gated ion channels so SODIUM can flow into the cell. This causes a more positive membrane potential, which is depolarization (closer to threshold).
An IPSP has inhibitory neurotransmitters that open the channels that let potassium out and chlorine into the cell. This causes a more negative membrane potential, which is hyperpolarization (further from threshold). |
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Know the role of serotonin, how serotonin levels are regulated in the synapse using a protein involved in serotonin transport. Know the mechanism of action of SSRI drugs that are used to treat depression.
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Serotonin affects mood, sleep, hunger, pain, memory, and behavior. Low levels lead to depression.
Levels are regulated by the serotonin transport protein, which reuptake serotonin back into the presynaptic cell…low levels are linked to depression so a drug used to treat depression causes serotonin to work less efficiently (a serotonin reuptake inhibitor). A person with two long alleles has the most proteins removing serotonin and is therefore most susceptible to depression. |
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ch49
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Compare the functions of the two divisions of the autonomic nervous system (parasympathetic and sympathetic). Know when each are stimulated, and the various results on target organs (such as heart, lungs, pancreas, stomach, eyes, adrenal glands, etc). (Figure 49.9)
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These have antaganositc effects on each other. The sympathetic division is energy intensive activities usually called the “fight or flight” response. It increases heart rate, breathing, and neurons that release epinephrine or norepinephrine. The parasympathetic division is a low energy state used to conserve energy called the “rest and digest” response.
They both stimulate AND inhibit. |
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last one cont.
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Parasympathetic Sympathetic
Constricts pupil of eye Dilates pupil of eye Stimulates salivary gland secretion Inhibits salivary gland secretion Constricts bronchi in lungs Relaxes bronchi in lungs Slows heart Accelerates heart Stimulates activity of stomach and intestines Inhibits activity of stomach and intestines Stimulates activity of pancreas Inhibits activity of pancreas Stimulates gallbladder Stimulates glucose release from liver; inhibits gallbladder Promotes emptying of bladder Inhibits emptying of bladder Promotes erection of genitals Promotes ejaculation and vaginal contractions |
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Compare the structures and functions of the central nervous system and peripheral nervous system. Explain the difference between cranial nerves and spinal nerves. (Figure 49.4)
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The CNS is the brain and the spinal cord, also containing interneurons. The PNS has (sensory and motor neurons) and then efferent/afferent neurons. The efferent neurons affect motor system and autonomic nervous system. The autonomic nervous system has a sympathetic, parasympathetic and enteric division.
- cranial nerves: branch off brain and send/receive signals between eyes, ears, nose, etc. - spinal nerves: branch off spinal cord and send/receive signals all over the rest of the body |
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Describe the functions of the human brain regions – medulla oblongata, pons, cerebellum, cerebrum.
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1. Medulla oblongata – controls involuntary activities (breathing, digestion, circulation)
2. Pons - regulates breathing in the medulla 3. Cerebellum – controls limb movement, motor responses, coordination, balance, hand-eye coordination, learning, remembering, and motor skills. 4. Cerebrum – is the majority of the forebrain it functions to handle complex thought processes and complex behavioral response, memory, learning, speech and emotions. |
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ch50
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Describe the structure of the sarcomere (Z lines, M line), know the types of filaments found in sarcomeres, as well as the proteins that make up the filaments.(Figure 50.27).
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Sarcomeres are made of protein cables with thick filaments and thin filaments interspersed. The Z line contains thin filaments and the M line contains thick filaments.
The light band is the place where only thin filaments are and the thick band is where they overlap Thick filaments are made of the protein myosin, which has a long chain of bendable heads that move. Thin filaments are made of the protein actin, which is coated with regulatory proteins. |
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Explain how muscles cells contract. Know the steps of the sliding-filament model of muscle contraction, and how contraction is regulated. Know the name, function, and organization of 4 proteins involved. (Figure 50.28, Figure 50.29)
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Contraction is made possible by the sliding filament model that is essentially thin filaments sliding across thick filaments. The Z lines are pulled toward the M line because thick pulls in thin. NOTHING gets longer or shorter.
There are four major proteins involved: -Myosin and Actin: A myosin head pulls actin in steps: ATP binds the myosin head, ATP transfers its energy to a myosin head to extend, myosin head binds to actin to form a cross bridge (myosin’s high energy state pulls actin), power stroke where the thin filaments are slid toward each other. Myosin can make 5 cross bridges per second. -Troponin complex and Tropomyosin: These two regulatory proteins coat thin filaments. They control access to myosin binding sites. When muscles are relaxed tropomyosin is bocking myosin binding. For muscle contraction calcium binds the troponin complex so tropomyosin falls off and myosin can bind. |
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Describe the structure of bone, noting the tissues that contribute to blood-forming tissues.
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Bones can be classified according to their shape: long (arms and legs), short (wrists and ankles), flat (ribs and skull), and irregular (vertebrae).
At each end of the bone there is an expanded version called the epiphysis that forms a joint with another bone and the location between two epiphysis; is diaphysis. Articular cartilage covers the end of the periosteum Compact bone is typically in the middle and just holds fat while spongy bone is on the end and has lots of little spaces that contains red bone marrow which functions to form blood cells. |
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Know the two cell types found in the bone, their function, and their role in bone remodeling and bone breakdown.
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Osteoblasts build bone, secrete minerals and collagen to create a hard matrix (b=build)
Osteoclasts break down bone and tissue, secrete acids and enzymes and release calcium (c=calcium) -osteocytes are dormant osteoblasts The bone is constantly being built and broken down because it always needs to be remodeled, they work antagonistically together. They adjust bone strength and exercise can increase bone density. Remodeling fixes fractures by the break and filling in the area. Bones store calcium, which is needed for neurotransmitter release that allows contraction. |
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Describe two hormones control the level of blood calcium by targeting bone cells, what cells they target, and the result.
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PTH causes osteoclasts to work harder. If your diet is low in calcium, PTH will target and activate. It can dissolve the hydroxyapatite crystals to release calcium into the blood. Calcium levels rise, but bone weakens.
Calcitonin causes the osteoclasts to work less, so bone gets broken down. (also growth hormone stimulates bone and muscle growth) |
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ch22
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Explain why paleontology and the use of fossils support the idea that living things change over time.
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Versions of a species change over time in groups. They have remnants of bones or parts of their body that developed or stopped being used based on what they needed. They evolved over time. The fossils change in groups over large periods of time so the species is developing and changing.
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Describe Lamarck’s two theories of evolution, and explain why they have been rejected.
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Lamarck stated species evolve through use and disuse. Meaning they develop and lose certain body parts over what is being used and not used. He also stated they evolve through the inheritance of acquired characteristics. This is wrong because species don’t change based on what is being used, but based on modification – variation in genes in DNA (which has nothing to do with use and disuse or acquiring things during a species actual life.
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Explain what Darwin meant by “descent with modification” as the mechanism for evolutionary change proposed in On the Origin of Species.
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Current species are descendants of older species and evolution is descent with modification…meaning two main ideas
1. descent with modification is so offspring can be different than generations before it and 2. natural selection drives evolution |
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List and explain Darwin’s observations, and how they are summarized in the acronym VISTA. (VISTA is not in the book, it will be presented in class).
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Darwin developed 2 main ideas – descent with modification and natural selection
V- Variation: observation #1 is members of a population of ten vary greatly in their traits – controlled by genes/DNA mutation I-Inheritance: some traits are inherited by offspring from parents S-Selection: observation #2: species produce more offspring than can survive. Many do not survive (predators, food source) if a certain heritable trait is beneficial it will be passed on T-Time: over time, some inherited traits give offspring a better chance to survive and reproduce A-Adaptation: accumulation of favorable traits in a population over generations (over time it adapts) Individuals do not evolve; populations evolve and environment drives evolution via natural selection - all living things are related. |
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Distinguish between artificial selection and natural selection.
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Natural Selection is the natural favoring of traits as they are passed on through time while Artificial selection is the decision by a human to favor certain characteristics so others are forced to be passed on over time
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List the four lines of evidence for evolution by natural selection, and know some examples (Concept 22.3)
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1. Fossil Records – versions of species buried below others; trilobites; change with groups over time; whales come from mammals
2. Homology – similarity resulting from common ancestry; compare things that are similar: homologus structures create a structural theme, vestifal structure are remnants from an organisms ancestors, comparative embryology is gills, ears, throats, etc., and DNA is comparing DNA between organisms 3. Biogeography – geographic distribution of species. The world started as pangea and develops..land evolved 4. Direct observation of evolutionary change – we have observed living things evolve in the last 200 years…think VISTA |
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Describe how fossil evidence supports evolution, and describe examples mentioned in class. (Figure 22.3)
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There are altering versions of species buried below others. Trilobites are marine animals and versions of them exist from 526 to 250 million years ago. Changes within groups over time are visible: whales are mammals (breathe air, have mammary glands, nurse their babies). Fossil evidence and bone structure support this – DNA as well.
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Describe the different types of homology comparisons used to support evolutionary theory.(Figure 22.15)
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Homologus Structures – structural theme present in a common ancestor (forelimbs)
Vestigal Structures – remnants from organisms’ ancestors…why whales have hindlimb bones Comparative embryology – pharyngeal pouches like gills, ears, throat and tail DNA – comparing DNA between organisms..instructions for organisms so humans and chimps have 96% identical DNA |
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Be able to interpret an evolutionary tree diagram. (Figure 22.17, 22.20)
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Things evolve from one common ancestor, if it stops before present time it is extinct, going right to left where two lines meet is a common ancestor.
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Describe how biogeography supports evolutionary theory.
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Geogrpahic distribution of species. So 250 million years ago the world was one large land mass called Pangea, 200 million years ago it breaks apart causing plants and animals to drift apart and adapt to varying environments. Land evolved with life.
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Explain examples of direct observations of evolutionary change mentioned in class (HIV, bacteria) and the selective processes that occurred to influence each.
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Evolution of drug resistant HIV: HIV is the virus that causes AIDS. The drug 3TC inhibits HIV enzyme, reverse transcriptase. This prevents viruses from replicating. After a few weeks of 3TC treatment , a patients HIV population consists entirely of 3TC resistant virus. Best explained by evolution, a few drug resistant viruses had to be present at the start of treatment (probably due to a DNA variation and Selection occurred in this environment…they adapted. (THE DRUG DID NOT CREATE MUTATIONS)
Evolution of drug resistant Bacteria: Staph causes skin infections. Penicillin was an antibiotic to cure staph and two years after its release penicillin resistant staph were developed. Methicillin is an antibiotic and two years after its widespread use methicillin resistant viruses (MRSA) existed. MRSA is considered a super bug. Most bacteria are resistant to both now. DDT was an extremely effective pesticide that was once predicted to permanently eradicate insect pests. DDT is now largely useless against most insects because too many individual insects possessed genomes that made them DDT resistant. The small % led to a high % (VISTA…genes/dna) |
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Explain why natural selection can act only on heritable traits.
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Natural selection is also “relative fitness” when certain alleles are passed to the next generation – meaning the genes that are better in specific environments are the ones that evolve.
It can only act on heritable traits because it can only amplify or diminish traits that can be passed from organisms to their offspring. An organism can adapt and acquire characteristics in its life, but these can’t be passed to offspring. 3 major types: directional selection – favors individuals at one end of a phenotypic range disruptive selection – favors extremes stabilizing selection – favors intermediate variants see graphs at end of notes |
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Explain the problem with the statement that Darwinism is “just a theory”. Distinguish between the scientific and colloquial use of the word “theory”. (sections at the end of the chapter).
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It is not just a theory because the observation that life has evolved over time has been documented directly and is supported by a great deal of evidence. The explanation of the process of evolution (natural selection as a primary cause) makes sense of massive amounts of data.
Colloquial use is close to what scientists use to describe a hypothesis. A real theory like the one of evolution accounts for many observations and explains and integrates a great variety of phenomena. Though a theory can change sometimes… for example evolution can happen over a short period of time.. it still has a solid foundation. Darwinism does attribute to a great amount of diversity of life. |
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ch23
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start
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Example how microevolution works.
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Microevolution is a change in allele frequencies in a population over time. It is due to genetic variation, a result of natural selection and genetic drift.
Allele frequencies fluctuate from one generation to another because 1. Natural selection with bb to Bb to BB and 2. Genetic Drift which is simply by chance and only a few reproduce. |
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Define the terms population and gene pool, and why being heterozygous is sometimes an advantage.
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Population is all of the organisms in a specific environment. A gene pool consists of all the alleles for all genes in a population for example b, B. Being heterozygous is sometimes an advantage because if you are heterozygous for sickle cell anemia you are immune to malaria…so sometimes though you inherit one bad trait you are protected from others.
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Explain the four mechanisms that give rise to genetic variation, and how each of them contributes to expanding the gene pool. Know examples mentioned in lecture.
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1. Formation of New Alleles by mutations – change in DNA sequence will change proteins, cells and then the organism. An allele comes from the original allele along with a mutation. Mistakes copying DNA (point, insertion, deletion) tiny change leads to a huge impact.
2. Altering gene number – duplicate genes and mutations to create brand new genes ex) translocation form one gene to another 3. Rapid reproduction - viruses and bacteria reproduce and evolve faster so they can replicate faster 4. Sexual reproduction - can give rise to new combinations of alleles (crossing over at meiosis 1, independent assortment during meiosis, fertilization) |
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Describe examples of microevolution (beak size in finches, beta-globin gene in humans, the HFE gene in humans), and explain these examples in terms of VISTA.
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1. The gene beta globin on chromosome 11 and the protein hemoglobin are allele A for normal and the allele “a” is mutant. It’s a point mutation causing a full amino acid change. Natural selection causes Malaria, which lives in red blood cells and kills you. Aa has a survival advantage, but also makes you susceptible to sickle cell anemia.
2.The gene HFE on chromosome 6 and protein that controls iron levels in blood are allele F for normal and “f” for mutant. It’s a small mutation but it causes higher iron in blood. Natural selection of bubonic plague can be killed by iron. Black death killed 1/3 of Europe ( FF and Ff had survival advantage…too much iron causes Hemchromatosis so if you have FF it’s a disadvantage) 3.Beak size is a gene with alleles B and b allowing three sizes. Small, medium and large…drought leaves only large seeds giving the large beak an advantage so after the drought one allele disappears. (nothing was created) |
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Distinguish among directional, disruptive, and stabilizing selection. Give an example of each mode of selection. Be able to apply these concepts to other examples.
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Directional selection favors individuals at one end of phenotypic range, so favors an extreme at one end. Ex) darker mice are favored because they live among rocks
Disruptive selection favors variants at both ends of the distribution. Ex) mice that live among a patchy set of rocks (leading to intermediate colors) Stabilizing selection favors intermediate variants from the population. Ex) rocks with a medium color so both light and dark are selected against |
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Explain the two types of genetic drift (bottleneck effect and the founder effect), and how they affect allele frequencies.
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Founder effect is when a few individuals become isolated from a larger population. The new group may establish a new population with a varying set of genes (different from the larger group) For example a few members are blown by a storm to a new island. Might account for the high frequency of certain inherited disorders among isolated human populations .
Bottleneck effect is a sudden reduction in population size due to a change in environment (storm, drought, asteroid) which creates less genetic variation. Simply by chance certain alleles may be overrepresented and some may be absent altogether. Ongoing genetic drift is likely to have substantial effects on the gene pool until the population becomes large enough that the chance events have less impact. (think of passing marbles through a bottle) |
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Describe how heterozygote advantage affects the gene pool.
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Individuals who are heterozygous at a particular locus have greater fitness than both homozygotes.. Natural selection tends to maintain two or more alleles at that locus (genotype not phenotype). Could be stabilizing or directional depending on the relationship.
For example the beta subunit of hemoglobin, sickle cell is caused by having a homozygous phenotype. |
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ch24
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start
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Define microevolution, macroevolution and speciation.
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Micro – a change in allele frequencies in a population over time due to genetic variation ( a result of natural selection and genetic drift
Macro – evolution over a longer period of time when one species splits into 2 ( a species is a population that can interbreed and produce viable, fertile offspring) Speciation – the origin of a new species |
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Describe the characteristic of a species.
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A species is a population that can interbreed and produce viable, fertile offspring
-Can’t or won’t breed with other populations -reproductive isolation or no gene flow between two species |
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Distinguish between prezygotic and postzygotic reproductive barriers.
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Reproductive isolation is barriers that prevent two species from mating and/or producing viable fertile offspring
-prezygotic barriers: before the egg and sperm interact -postzygotic barriers: offspring is a hybrid that isn’t fertile or viable (cross between two species) |
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Describe the five prezygotic barriers and three postzygotic barriers, know an example of each, and be able to apply the barriers to new examples.
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Five prezygotic barriers:
1. habitat isolation- when a species lives in 2 different environments ex)land/water snake 2. temporal isolation –when the animals breed at different times of the day or different seasons ex)hibernating animals 3. behavioral isolation-altering mating rituals ex) blue footed boobies (birds) 4. mechanical isolation – when the genitalia does not match ex) shells of two snails 5. gametic isolation – sperm and egg won’t fuze to form a zygote ex) closely related aquatic animals |
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three postzygotic
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Three postzygotic barriers:
1. Reduced hybrid viability – the baby can’t or won’t develop ex) salamander populations 2. Reduced hybrid fertility – the offspring is unable to reproduce itself ex) the cross of a donkey and a horse leads to an infertile mule 3. Hybrid breakdown – offspring are viable and fertile, but when they mate with each other or either parent species that offspring is infertile |
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Explain how speciation is occurring in North American hawthorn maggot flies (Rhagoletis pomonella).
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The north American maggot flies layed eggs and mated in hawthorn fruit but in the 1800’s when the apple tree was introduced some flies preferred to mate here (variation) soon gene pools started to separate and the apple flies preferred one another, as did the hawthorn flies. Apple trees give fruit earlier in the fall so soon apple preferring flies started to develop sooner. 150 years later these flies (apple and hawthorn) can’t/won’t/don’t mate with each other… they are a different species
Habitat, temporal and behavioral isolation all occur here. They live in different places, develop at different times, and prefer different things. |
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Distinguish between allopatric speciation and sympatric speciation, and describe mechanisms that may lead to each.
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1. Allopatric speciation – the population is divided into geographically isolated subpopulations, there is a physical barrier between them. They have no gene flow and they will eventually not mate. They evolve separately with different predators, food source and more
2. Sympatric speciation – populations live together, but reproductive barriers form. Habitat differentiation: the appearance of new habitat or food source and Sexual selection: females develop preference for new mate |
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Discuss the factors that allow for speciation to occur.
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Speciation can happen for a variety of reasons.
- typically it is because of some sort of environmental change: food source, predators, climate. All the effects: reproductive barriers, geographically isolation, large impacts (droughts) and more could cause and lead to speciation |
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Describe examples of speciation mentioned in class, and be able to apply mechanisms of microevolution and speciation to them (such as the silver fox example).
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The major example of speciation is the silver fox example (the evolution of dogs – who have very similar DNA with wolves). 50,000 years ago with waves. Humans intervened with artificial selection and it was called the Russian Silver Fox experiments. The foxes bred in captivity for their fur, they are aggressive and scared of people. In 1959 the foxes were able to become domesticated. Non aggressive and friendly foxes were selected for breeding, but they gained unexpected traits like barking, ears, coat color, and varying hormone level causing a cascade of other changes. Much higher adrenaline levels caused coat color to change. They didn’t select for this but it appeared and caused a new species. A population evolved…tameness led to floppy ears, curly tails, short legs, blue eyes (all things that never existed in foxes)
-maggot flies -other examples above |
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ch25
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start
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Describe the four conditions required for the origin of life on Earth, and in what order they likely occurred.
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Small organic molecules (amino acids, nucleic acids, etc), polymers (joining of small molecules into macromolecules), packaging of molecules/polymers into membranes, self replicating and inheritance – in that order
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Describe how experiments performed by Miller and Urey contributed to the theory of how life on earth formed.
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The Miller and Urey experiment in the 1950’s mixed chemicals, electricity and heat in a small ball. This generated many organic compounds like amino acids, sugars and lipids. This shows the spontaneity of things that can form and points out the underwater volcanic vents might have created some of these compounds because of their conditions.
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Explain the significance of the discovery of ribozymes.
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A ribozyme is an enzyme made of RNA (unlike most of todays made of protein) The ribozymes are able to self replicate, mutate and evolve on there own. In 2009 an experiment was done showing that they could compete and evolve for a food source and at the end only one type of strong RNA existed. It is called “self-sustained replication of an RNA enzyme”
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Describe how protocells could have played a role in organizing chemical reactions.
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Protocells are compartments that can self assemble from free lipids to form liposomes – something like a plasma membrane. They can undergo simple reproduction and they have a cytoplasm. They form spontaneously if you leave the building blocks all together so they may have created the membranes to bind these building blocks together and allow reactions to occur.
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Describe the major events in Earth's history from its origin until the present. In particular, note when Earth first formed, when life first evolved, what types, and in what order.(Figure 25.7)
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Earth was first formed 4.6 billion years ago and we first see prokaryotes about 3.5 billion years ago. These single cell organisms lived on the earth for 1.5 billion years alone and since they were photosynthetic bacteria they created oxygen. About 2.1 billion years ago eukaryotic cells appear (such as yeast). Then multicellular eukaryotes (balls of cells) appear about 1.5 billion year ago – these arose from mutations. Animals appear 535 – 525 million years ago…the multicellular balls start to become specialized, initial animals were mollusks, sponges and anemones in the sea. They were very simple. Next came plants, insects and then animals moved from the ocean to the land.
This was all established by fossil evidence. |
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Describe how oxygen first accumulated in the Earth’s atmosphere. (Figure 25.8)
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They came prokaryotes that could produce oxygen via synthetic bacteria. Most atmospheric oxygen is of biological origin from photosynthesis, it dissolved in water until it reached a high enough concentration about 2.7 billion years ago. Oxygen releasing, photosynthetic bacteria were alive long before this.
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Explain the function of Hox genes. Be able to explain examples of differences in Hox genes between species (chicks and snakes, flies and brine shrimp). (Figure 25.23) (Figure 25.24)
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Hox genes are a type of homeotic gene (master body plan genes that make proteins and control growth at embryonic development). They control position in animal embryos - they can be turned on or off at different times of development (they are in all animals at different numbers and timing). Hox gene changes can change an organism and gene regulation
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two examples
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- Hox6C Gene controls limb development by making proteins to suppress limbs. All animals have this, in varying animals it turns on at different points suppressing limb growth… in chicks it is on in a small fraction of the spine (so legs and arms grow) but in snakes it is fully on (so there is no limb growth)
- UbX Hox Gene controls limb development by telling the where to go or not go, when its on growth is less powerful…in fruit flies they have front legs while shrimp have legs along their whole body because its on in fruit flies. Mutations in this gene are how leg and arm development alter. |
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Describe the significance of the differences in Pitx1 gene expression between marine sticklebacks and lake sticklebacks. (Figure 25.25)
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These fish have spikes on their body which area great mechanism and they live primarily in the ocean. When they ended up in the lake they found there were no predators there and that the spikes were not necessary. The PX1 gene controls the spike formation in the embryo and for lake sticklebacks the variation of this gene producing no spikes was inherited (this was good because spikes take energy). This happened over time, but selection occurred showing a more beneficial form of energy.
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