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109 Cards in this Set
- Front
- Back
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What 7 Things should a Balanced diet include?
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Protein, Carbohydrates, Lipids, Vitamins, Water, Minerals, and Dietary Fibre.
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Test for Glucose:
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Add blue Benedict's solution, and if glucose is present it will turn orange-red when heated.
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Test for Iodine:
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Reddish-brown iodine solution turns blue-black with starch.
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How do you determine the energy content of food>
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By burning it and using to heat a measured sample of water. This is a simple calorimeter.
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What does Vitamin A do? Where do you get? Deficiency disease?
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Makes chemicals in retina of the eye, protects surface of eye and connective tissues. Fish Liver Oils + Butter. Night Blindness (DD)
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What does Vitamin C do? Where do you get? Deficiency disease?
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Sticks together cells lining surfaces in the body (mouth). Citrus Fruits. Scurvy.
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What does Vitamin D do? Where do you get? Deficiency disease?
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Helps bones to absorb calcium and phosphorus. Fish liveroils, butter. Rickets.
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What does Calcium do? Where do you get? Deficiency disease?
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Helps bones and teeth. Dairy products.
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What does Iron do? Where do you get? Deficiency disease?
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Makes haemoglobin in red blood cells to carry oxygen. Red meat, eggs. Anaemia.
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How do energy requirements vary?
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With age, profession, gender, and pregnancy.
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What does the process of breaking food down involve?
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Ingestion, Digestion, Absorption, Assimilation, and Egestion. (I Don't Always Admire Elephants.)
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How is food moved through the gut?
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Peristalsis, contractions between the circular muscles and the longitudinal muscles.
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How is food broken down?
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By enzymes.
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What is bile?
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It's released to neutralise stomach acids and emulsify fats, making it easier for the lipase to digest. It's made in the pancreas and stored in the gall bladder.
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How are villi adapted for blood exchange?
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Increase the surface area available for the absorption of digested food molecules. They have short diffusion differences as the cells are thin, and have a good blood supply to maintain a steep concentration gradient.
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What 3 ways is food used?
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Providing energy for the cells, providing material needed for growth and repair, and providing resources needed to fight disease and stay healthy.
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What are carbohydrates?
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They're sugar and starches, made up of atoms of Carbon, Hydrogen, and Oxygen joined together. They're found in rice, pasta, bread. They provide energy for the cells. Simple carbohydrates like glucose and sucrose and sugars.
Complex carbohydrates like starch, glycogen, and cellulose are long chains of sugars such as glucose or fructose joined together. |
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What are proteins?
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Long chains of amino acids found in food such as meat, cheese and fish. Consist of Hydrogen, Carbon and Oxygen, but also have Nitrogen and Sulfur atoms.
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What are lipids?
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Made up of fatty acids and glycerol joined together. Found in foods such as butter, corn oil and eggs. Contain lots of energy and are used as an energy store in the body. Lipids are made up of carbon, hydrogen, and oxygen.
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What is energy measured in?
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J, Joules. It's important to take in the right amount of food.
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Why is water important?
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As a solvent for breaking up large molecules by hydrolysis, and for carrying substances around your body. You need plenty clean water daily.
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Why do you need fibre?
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You need fibre in your diet for bulk to give the muscles of the gut something to work on. It also absorbs lots of water.
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What do enzymes do?
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As food is made up of large insoluble molecules, you need small soluble molecules, and the physical and chemical breakdown of your food by enzymes takes place in the digestive system.
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What is the alimentary canal? HOw does food run through your gut?
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It's a muscular tube that runs from your mouth to your anus. Food runs through your gut by waves of muscle contraction. You produces enzymes which digest food in glands that are found in several different organs of your digestive system. These include your salivary glands, your pancreas and your ileum.
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What is absorption?
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The products of digestion are absorbed into bloodstream by the small intestine. The lining of the small intestine is covered by villi.
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Cabohydrase (Amylase, Maltase): Where It's Found in the Gut: What it acts on: What are the breakdown products?
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Salivary glands, pancreas, small intestine. Starch. Glucose.
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Protease (Pepsin, Trypsin): Where It's Found in the Gut: What it acts on: What are the breakdown products?
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Stomach, pancreas, small intestine. Protein. Amino Acids.
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Lipase. Where It's Found in the Gut: What it acts on: What are the breakdown products?
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Pancreas, Small Intestine. Lipids. Fatty acids and glycerol.
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What is assimilation?
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The digested food products are absorbed into the cells of the body by diffusion and assimilated. They are used for energy and to build up into chemicals needed by the cells.
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What is egestion?
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Water, undigested food, enzymes, dead cells, bile pigments and mucus move through the large intestine. Water is removed. The remaining material is passed out of the anus as faeces.
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Plants: Type of organism? Example?
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Plants are multicellular and carry out photosynthesis. Examples include Maize and peas. They carry out photosynthessis using carbon dioxide and water to make sugar and oxygen. They capture energy from the sun using chlorophyll in their chloroplasts. THey store carbohydrates as starch. Plant cell walls are made of cellulose. There are simpler non-flowering plants such as mosses.
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Animals: Type of organism? Example?
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Animals are multicellular, and need to feed on other living organisms to get their energy, examples include humans, worms, insects. They cannot carry out photosynthesis as they don't contain chlorophyll. Don't have a cell wall. Most have a form of a nervous system for coordination. They move their whole bodies about. The carbohydrate stored in animals in glycogen.
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What are vertebrates?
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Vertebrates are animals that have a backbone. They include fish, amphibians, reptiles, birds, and mammals. All other animals are invertebrates - they don't have a backbone. They include sponges, molluscs, worms, starfish, insects and crustaceans.
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What are fungi?
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Fungi are organisms that feed off other organisms. They are saprophytes or parasites. Some fungi are multiceullular, such as mushrooms, toaddstool and moulds. Some are unicellular. Fungal cells have cell walls that are made of chitin, whereas plant cell walls are made up cellulose. Multicellular fungi are made of a mycelium, which is a tangled network of thread-like structure hyphae.
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How do fungi feed?
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They secret enzymes which digest their food outside the cells. Then they absorb the digested products. This is a saprophytic nutrition. Many fungi act as decomposers.
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What are the major groups of classification?
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Animals, plants, fungi, protoctists, bacteria and viruses.
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What are protoctists?
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Some protoctists make their own food by photosynthesis and some feed on other organisms. Most are unicellular but some are multicellular. Some cause disease. Some cause diseases, plasmodium causes malaria. Example is seaweed.
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What is Bacteria?
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Tiny single celled organisms that are much smaller than animal cells. Common shapes include spheres, rods and spirals. They have a complex cell wall made up of polysaccharides and proteins, different from the cellulose of plant cell walls and the chitin of fungal cell walls.
Bacteria don't have a nucleus. The genetic material forms a circular loop in the cytoplasm. Small extra circles of DNA are known as plasmids. Some bacteria contain chlorophyll and can photosynthesise. Most feed on dead or other living organisms. Some bacteria have slime capsules for protection of flagella for movement. |
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What are prokaryotes?
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Prokaryotes are single-celled organisms that don't have a nucleus. Most prokaryotes are bacteria but they also include the archaea. They're similar to bacteria but some of their cell chemistry is different.
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What are Viruses?
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Viruses are parasites and can only reproduce inside the living cells of a host. Viruses are even smaller than bacteria. Virus particles are very simple and are found in many different geometrical shapes. They have a core of genetic material surrounded by a protein coat. Viruses contain either RNA or DNA but not both. All viruses each cause disease and every type of living organisms, even bacteria can be infected by viruses. Each type of virus causes a specific disease in the particular it's adapted to infect, e.g flu, HIV/Aids.
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What does Asexual reproduction involve?
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Only one individual. It gives identical offspring known as clones. It involves mitosis. The number of chromosomes in the cells remains the same. Some advantages are that reproduction is guaranteed, and can produce many offspring, However if the environment changes the lack of variety in the genetic make up of the organisms will mean they're unlikely to survive.
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What does sexual reproduction involve?
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Two gametes from different parents. In fertilisation these sex cells fuse to form a zygote, a new genetically unique individual. The zygote undergoes cell division and develops into an embryo. This is done by meiosis. The number of chromosomes are halved when the gametes if formed. The offspring contain a mixture of genetic information from both parents. Sexual reproduction produces genetic variety.
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What happens to the sex organs at puberty?
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They mature and become active.
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What happens in the male reproductive system?
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Produces sperm in the testes. They travel from the testes to the sperm such, with secretions from the seminal vesicle an the prostate gland to make semen.
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What happens in the female reproductive system?
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Ovaries release mature ova from developing follies once a month in the menstrual cycle. The uterus develops a blood rich lining each month to prepare for a pregnancy. If an ovum is fertilised it will implant in the lining. If not, the lining is shed as the monthly period occurs.
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What controls the menstrual cycle?
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Hormons released from the pituitary gland (FSH & LSH) and from the ovary (Oestrogen and Progesterone).
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What happens when the sperm and the ovum meet in the Fallopian tubes?
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One sperm may penetrate the ovum. THis is the moment of fertilisation or conception.
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How long does it take for the fertilised ovum to grow and mature into a fully developed foetus ready birth?
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Around 40 weeks (9 months).
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What are male secondary sexual characteristics during puberty?
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Growth of penis and testes, the growth of facial and body hair, muscle development, voice breaking, all controlled by hormones, FSH and LH are released by the pituitary gland. FSH stimulates sperm production while LH stimulates the testes to produce the male sex hormone testosterone. Testosterone causes the development of the male secondary sexual characteristics.
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What are female secondary sexual characteristics during puberty?
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Breasts develop, body hair and the beginning of the menstrual cycle. FSH and LH are released by the pituitary gland. FSH stimulates the development of mature ova in the ovaries. They also interact with the female sex hormones oestrogen & progesterone.
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What happens in the menstrual cycle?
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Following puberty, a woman will have a menstrual cycle approximately once a month. The menstrual cycle stops when a women is pregnant, and starts when the baby is born. They stop completely when she reaches menopause.
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What hormones are secreted from the pituitary gland?
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Follicle Stimulating hormone stimulates ova in the follicles of the ovary to develop. LH Luteinising hormone stimulates the release of a mature egg from the ovary. It also stimulates the ovary to make progesterone.
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What hormones are secreted from the ovaries?
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Oestrogen stimulates the lining of the uterus to build up. It also reduces the levels of FSH. Increases the LH.
Progesterone stimulates the growth of blood vessels in the lining of the uterus getting reading for a pregnancy. If a fertilised ovum arrives in the uterus, progesterone helps to keep the pregnancy going. |
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What happens in Pregnancy?
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Sperm fertilises an ovum and forms a zygote in the Fallopian tube, a pregnancy begins. The developing embryo moves into the uterus. It needs to be implanted in the lining of the uterus for the pregnancy to continue. As the embryo develops, the placenta forms.The placenta is a special organ that passes food and oxygen from the mother to the developing fetus. It also takes urea and carbon dioxide from the fetus and them into the mother's blood, and secrets the hormone progesterone which maintains the pregnancy.
The fetus is connected to the placenta by the umbilical cord. Inside the uterus it's surrounded by amniotic fluid in the amniotic membranes. THis cushions and protects the fetus as it develops. |
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What is photosynthesis?
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The process by which plants make food. Light energy is converted to chemical energy in the process.
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What is the Word & Symbol Equation?
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6CO2 + 6H2O > C6H12O6 + 6O2
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What affects the rate of photosynthesis?
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It's affected by Carbon Dioxide concentration, light intensity, and temperature.
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What do plants require for growth?
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Mineral ions, such as nitrate to make amino acids to build up proteins, and magnesium is needed to make chlorophyll.
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Talk about the process of photosynthesis:
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Laves of plants make glucose from Carbon Dioxide and water using light energy from the sun. This energy is captured by chlorophyll in the chloroplasts of the leaves and converted to chemical energy in glucose. Oxygen is also produced as waste product. Glucose is converted into sucrose to be transported around the plant, and into to starch to be stored.
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What experiments can you use to demonstrate photosynthesis?
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Destarched plant, one that has been kept in the dark. Know if starch is produced as a result of photosynthesis. You can demonstrate starch is present by boiling it in ethanol, then rinsing it in water, and testing for starch using iodine solution.
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How do you show photosynthesis is present with the presence of Oxygen?
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By using an aquatic plant such as canadian pondweed in bright light. Capture the gas produced and analyse it to show raised oxygen levels, or simply count the number of gas bubbles given off. To show that chlorophyll is needed, we use a variegated leaf. This is limited use as the products of the carbon dioxide is needed, remove CO2 from air surrounding one plant using soda lime. This is of limited use as plants make CO2 during respiration. Tho show light is needed, you cover part of the plant so it's not exposed to light and you can show that starch isn't made in that region of the plant.
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What is the glucose made in photosynthesis used for?
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The glucose made in photosynthesis is used to make sucrose for transport, starch for storage, cellulose for cell walls, protein and DNA, lipids as an energy store in seeds and chlorophyll.
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How is the leaf adapted for photosynthesis?
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Plant leaves are thin and flat to absorb the maximum amount of light, and the distance are short that gases need to diffuse from.
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Why does CO2 levels and Oxygen levels change?
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Oxygen is produced during the day, as photosynthesis depends on light levels, so there is more carbon dioxide at night.
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What is a limiting factor?
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A limiting factor is the component of a reaction that limits the rate of a reaction as it's in short supply. The main limiting factors of photosynthesis are light intensity, temperature, and carbon dioxide levels.
You can use pondweed to demonstrate this. |
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How do plant take up mineral ions?
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They take them from the soil. This means they use active transport as the mineral ions are taken up against a concentration gradient. Plants need nitrates to make amino acids, which are built up into proteins, and magnesium to make chlorophyll.
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What does blood clotting do?
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Blood clotting prevents blood loss and protects against the entry of pathogens. In vaccination the immune system make memoral cells and is stimulated, and so future exposure to a pathogen results in rapid production of large numbers of the right antibody to prevent disease.
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Why do people need a transport system to carry sugar and oxygen to cells for cellular respiration?
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As they have a small surface area to volume ratio.
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What waste products must be produced?
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Carbon Dioxide and urea.
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What is Double Circulation?
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Humans have it, and the heart pumps blood around the lungs to pick up oxygen. Oxygenated blood flows back to the heart. It's then pumped out around the body in the systemic circulation.
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What are arteries?
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They have thick muscular walls to smooth out the pulse of blood flow form the heart. They usually carry oxygenated blood away from the heart, except the pulmonary artery, which carries deoxygenated blood to the lungs.
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What are capillaries?
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They have walls and are very thin so blood can exchange dissolved food and gases easily with the cells through diffusion. Substances diffuse in and out of the blood in the capillaries.
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What are veins?
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Veins are large to carry blood under low pressure back to the heart. They usually carry deoxygenated blood back to the heart from the tissues, except the pulmonary vein in the heart which carries oxygen blood from the lungs to the left atrium. Veins have valves.
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Where does blood enter the heart?
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In the atria. These contract which forces the blood into the ventricle. When the ventricles contract, blood leaves the heart to go to the lungs, and around the body. Both sides of the heart fill and empty together.
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How does the heart beat?
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It beats around 70 times a minute, and is controlled by the pacemaker region of the heart. The rate changes as the demands of the body change. During exercise for example, more food and oxygen are needed by the cells, and more carbon dioxide is produce, so it beats more rapidly and strongly.
You can do an experiment for this by measuring your pulse under different conditions. |
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What happens when the chambers of the heart contract?
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It forces blood out into the arteries, the heart is in systole. When it relaxes and fills, it's in diastole. The blood pressure in the arteries changes as the heart empties and fills - it's higher as it's higher as the heart pumps and empties, lower when it relaxes and fills.
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What is plasma?
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Yellow liquid which transports dissolved food molecules, carbon dioxide and urea as well as all the bloody cells. It's mostly water.
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What are red blood cells?
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They're bio concave, and contain haemoglobin and transport oxygen.
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What are white blood cells?
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They defend the body against attack by microbes. Lymphocytes produce antibodies to destroy microorganisms and lymphocytes give us immunity to specific diseases. Phagocytes engulf and digest microorganisms.
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What are platelets?
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Cell fragments which help clot the blood.
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What is diffusion?
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How substances move from between the blood and the cells through the tissue fluid.
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What is the Lymph system?
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It's the tissue fluid that travels around the body. When it returns to the blood it's rich in antibodies against disease.
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How does blood clot?
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You have the injury. Platelets arrive. Platelets break open. If calcium ions are present, thrombin is formed. This acts of fibrinogen to turn it to fibrin. This forms mass of insoluble protein threads which forms a clot and then a scab as red blood cells become trapped in it.
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What is the immune response?
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White blood cells protect the body against pathogens. 70% are phagocytes. Pathogens have antigens on their cell surfaces, so lymphocytes make antibodies in response to these antigens. The antibodies stick to the antigens and destroy the pathogen in one of several ways:
Making the pathogens stick together so that phagocytes engulf them more easily. Acting as a label so that phagocytes recognise the pathogen more easily. Causing bacterial cells to burst open. Neutralising toxins produced by bacteria. Some lymphocytes form memory cells so that if the pathogen gets into your body again it can be dealt with quickly before you are affected by the symptoms of the illness. This secondary immune response is much faster and stronger than the first one. |
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What is an ecosystem?
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A distinct, self-supporting system of organisms interacting with each other and with their physical environment.
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What is a population?
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All the organisms of a specific species living in an ecosystem and a particular time.
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What is a community.
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All organisms living in an ecosystem at a particular time.
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What is a habitat?
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Where organisms live.
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What are quadrats?
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Big square things used to sample the distribution of organisms in their habitats, and to estimate the population size of an organism in different areas.
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How much energy is transferred onto the next trophic level? How is it lost?
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About 10% as:
Some parts of the organism aren't eaten. Food cannot all be digested and absorbed, some is passed out as faeces. Some of the food is broken down and excreted as waste, e.g urea. Some of the food is respired and used to release energy in cells of the body. Only a small part of the food is used to produce growth and new body mass. |
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What organisms are decomposers?
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Bacteria and Fungi. They break down and decompose dead material and waste products to recycle the nutrients.
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What affects population size?
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Physical environment such as temperature, level of rainfall and amount of sunshine.
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What is pyramid of numbers?
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Either like biomass, or like A CHRISTMAS TREE.
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How is energy transferred between organisms?
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Light energy is fixed into food molecules by plants udring photosynthesis. Energy is released during respiration and used for movement, growth, reproduction. Energy that is used for growth can be passed on to the next trophic level or the decomposers. Energy used for any other process will eventually be transferred to the environment as heat.
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Describe the Carbon Cycle?
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Photosynthesis fixes carbon atoms from atmospheric CO2 into organic molecules. These carbon containing molecules are then passed along food chains by living organisms. Respiration by the living organisms releases carbon dioxide back into the atmosphere as organic compounds that are broken down to release energy.
At the same time, fossil fuels formed from the remains of plants and animals store carbon compounds, and combustion of the fuels releases carbon dioxide back into the atmosphere. |
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Describe the Nitrogen Cycle?
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Nitrogen in the atmosphere can't be directly used by most living organisms.
The Nitrogen Cycle includes the following processes: Nitrogen atoms in organic compounds are passed along food chains. Decomposition produces ammonia as proteins, amino acids are broken down. Nitrifying bacteria oxidise the ammonia to nitrites and then to nitrates in a process called nitrification. Plant roots can absorb nitrates and use them to make organic molecules such as proteins. Free-living nitrogen fixing bacteria in the soil converts nitrogen gas into ammonia, which is then used to make proteins. Ammonia is released into the soil when they die and decay. Nitrogen-fixing bacteria in root nodules makes ammonia, which the plants use to make amino acids. Denitrifying bacteria use nitrates as an energy source and break them down into nitrogen gas. |
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Describe the Water Cycle:
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Driven by heat from the sun, water is recycled between the atmosphere, rivers, lakes, and organisms and back to the sea. It involves evaporation from bodies of water, transpiration from plants, condensation in the atmosphere as the temperature drops, and precipitation.
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What does the gas exchange system do>
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Takes air into and out of the body to supply oxygen and remove carbon dioxide.
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How does air move in and out of the lungs?
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By breathing movements of the ribs and diaphragm. The air movement maintains a steep concentration gradient for the diffusion of oxygen and carbon dioxide between the blood and the air in the lungs.
The complete gas exchange system includes the ribs, the intercostal muscles, the diaphragm, the trachea, bronchi, bronchioles, alveoli, and pleural membranes of the thorax. Gas exchange takes place in the lungs and depends on efficient diffusion of gases. |
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What is cellular respiration?
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The process that releases energy food in your cells. You need a constant supply of oxygen for this to happen aerobically. You also need to have the waste CO2 removed.
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How is the gas exchange system adapted to allow the exchange of oxygen and carbon dioxide to take place as efficiently as possible?
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You bring air into your body through your mouth and nose. It's made warm and moist on the way in, and dirt and pathogens are filtered out of it by cilia and mucus. The lungs are the organs where gas exchange takes place.
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What are the nasal passages? Epiglottis? Oesophagus? Larynx, and Trachea?
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NP - Warm, clean and add moisture to the air.
E - Stops food getting into lungs when you swallow. O - Carries food to the stomach. L - Voice Box. T - Tube with incomplete rings of cartilage, leaving cells making mucus and cells with cilia which takes the mucus away from the lungs |
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What is the left bronchus, bronchioles, alveoli?
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B & B - Carries air to lungs.
A - Tiny air sacs adapted for gas exchange. |
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What is the diaphragm, ribs, Internal & External intercostal muscles, and pleural membranes and fluid?
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D - Sheet of muscle with a fibrous middle part which is domed; it helps make breathing movement and separates the thorax from the abdomen.
R - Bones that protect and ventilate the lungs. When you breathe out, the internal intercostal muscles pulls rib down and in. Opposite for breathing in with external intercostal muscles. PM - Thin moist membranes forming an airtight seal around lungs and separating inside of thorax from lungs. PF - Liquid filling pleural cavity and acting as lubrication, so surfaces of lungs don't stick to inside of chest wall. |
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Describe the Ventilation of the Lungs?
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Air's moved into and out of the lungs by the movement of the ribs and diaphragm. Ventilation brings in oxygen-rich air and removes air containing carbon dioxide. It maintains steep diffusion gradient in the alveoli. There's always more oxygen and less CO2 in the air in the blood. The ventilation movement of the ribs and diaphragm bring about changes in the volume and therefore the pressure of the chest cavity.
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What happens for inhalation?
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Air enters lungs, lower pressure than outside body, volume of chest cavity expands, diaphragm muscles contract, diaphragm flattens, external intercostal muscles contract, pulling ribs up and out.
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What happens for exhalation?
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Air is pushed out of lungs, higher pressure than outside of body, diaphragm muscles relax, becomes dome shaped, volume of chest cavity decreases. Internal intercostal muscles contract, pulling ribs down and in.
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How are alveoli adapted for gas exchange?
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There are millions of tiny air sacs called alveoli in the lungs. They're adapted for efficient gas exchange. Blood is pumped form the heart to the lungs and passes through the network of capillaries surrounding the alveoli.
Carbon Dioxide diffuses from the blood into the air in the alveoli. Oxygen diffuses from the air in the lungs into the blood. The oxygenated blood ravels back to the heart to be pumped around. Alveoli have a large surface area, a rich blood supply which removes oxygen from and delivers carbon dioxide to the air in the alveoli, maintaining a steep diffusion gradient between the alveoli and blood. There are short diffusion distance between the air and blood. |
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Smoking and Health: 8 Points Please
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1. Nicotine is the addictive drug found in tobacco. It's addiction that makes it hard to give up.
2. Carbon monoxide reduces the amount of oxygen carried in the blood of smokers. 3. Tar and other chemicals in tobacco smoke can cause lung cancer, bronchitis, emphysema and diseases of the heart and blood vessels. 4. Tobacco has the following effects: Cilia are destroyed so dirt and bacteria aren't removed. 5. Emphysema - the walls of the alveoli are damaged and break down to form large irregular air spaces which don't exchange gases efficiently. 6. Lung cancer - tar and other chemicals cause cells to mutate and form cancers in the lungs and throat. 7. Carbon monoxide bind to haemoglobin, lowering the oxygen levels in the blood. In pregnant women, this deprives the fetus of oxygen and can lead to smaller babies and still birth. 8. Smoking also affects the circulatory system and causes an increased risk of heart attacks and strokes. |
