Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
240 Cards in this Set
- Front
- Back
|
What is the cell membrane? |
Controls what can enter and leave the cell. semipermeable |
|
|
What is the nucleus? |
Houses and protects the DNA which controls the activities of the cell |
|
|
What is the cytoplasm? |
Contains enzymes to carry out reactions in the cell |
|
|
What are the mitochondria? |
Where aerobic respiration takes place, energy is released from them |
|
|
What are the ribosomes? |
Where protein synthesis happens |
|
|
What are the chloroplasts? |
Contain a green pigment called chlorophyll, absorb light energy to make food through photosynthesis |
|
|
What is the cell wall? |
Made from a substance called cellulose, strengthens the cell and gives it shape |
|
|
What is the permanent vacuole? |
Contains cell sap that keeps the cell turgid |
|
|
What are plasmids? |
Rings of DNA in a prokaryotic cell |
|
|
What type of cell has mitochondria. Prokaryotic or eukaryotic? |
Eukaryotic |
|
|
The DNA in a prokaryotic cell is..? |
A single circular strand of DNA floating freely in the cytoplasm, small may contain small rings of DNA called plasmids |
|
|
What is differentiation? |
The process in which cells change to become specialised for a job |
|
|
What are stem cells? |
Cells that don't have a specific role within a human |
|
|
Where are stem cells found? |
In bone marrow, embryos and plants |
|
|
Sperm cells: specialised for and adaptations |
Reproduction- getting the male DNA to the female DNA. Flagella that helps it swim to the egg, streamlined head that can break off easily, lots of mitochondria to provide energy, enzyme in head to digest egg cell membrane, half the number of chromosomes |
|
|
Nerve cells: specialised for and adaptations |
Rapid signalling- carry electrical signals from one part of the body to another. Long to cover more distance, branched connections at the ends to connect to other nerve cells and form a network through the body |
|
|
Muscle cells: specialised for and adaptations |
Contractions- to contract quickly. Long so they have space to contract, lots of mitochondria so they have the energy to contract |
|
|
Root hair cell: specialised for and adaptations |
Absorbing water and minerals. Large surface area for absorbing water and mineral ions from the soil |
|
|
Phloem: specialised for and adaptations |
Transporting substances- food. Small pores to allow substances to flow through, mitochondria to provide energy, very few sub-cellular structures so particles can flow |
|
|
Xylem: specialised for and adaptations |
Transporting substances-water. Hollow tubes to allow water to flow. Strengthened by lignin |
|
|
Egg cell:specialised for and adaptations |
Reproduction- Large so the sperm can get in easier, jelly coat to protect it, lots of nutrients, mitochondria for mitosis, cell membrane only allows one cell to enter, half the amount of chromosomes |
|
|
Ciliated epithelial cells: specialised for and adaptations |
Clear bacteria and mucus from lungs to be swallowed. Lots of mitochondria to keep the cilia moving, on the top of the cell |
|
|
Red blood cell: specialised for and adaptations |
Carry oxygen. Bioconcaved which increases surface area, no nucleus to carry more oxygen, contains haemoglobin |
|
|
White blood cells: specialised for and adaptations |
Destroy pathogens. Lymphocytes have a large nucleus to make antibodies, Phagocytes can change shape to engulf pathogens |
|
|
What is resolution? |
The minimum distance between two objects where they can still be seen as two separate objects |
|
|
Advantage of light microscope |
We can observe living cells |
|
|
Disadvantage of light microscope |
It has a poor resolution |
|
|
Advantage of electron microscopes |
They have a much better resolution than light microscopes |
|
|
Disadvantages of electron microscopes |
You cannot view living specimens and the specimen often has to be carefully stained and very thin. The conditions can cause false images. |
|
|
What is aseptic technique? |
A method designed to prevent contamination from microorganisms. |
|
|
What is the inhibition zone? |
A clear area where the bacteria has died around an antibiotic or antiseptic |
|
|
How many pairs of chromosomes do humans have? |
23 pairs |
|
|
What is mitosis? |
Mitosis is cell division that happens for growth, repair and asexual reproduction in plants. The parent cell divides into two daughter cells which are genetically identical to each other and the parent cell. It happens in eukaryotes |
|
|
Stages of mitosis |
Chromosomes shorten and fatten Chromosomes double now called chromotids Chromotids align in the middle of the cell A spindle of fibres start to form The spindle of fibres start to shorten pulling the chromotids apart There are now two sets of identical chromosomes Membranes form around these to form nuclei- the nucleus has split Then the cell wall and membrane split Now there are two identical daughter cells |
|
|
What types of cell can an embryonic stem cell turn into? |
Any type of cell |
|
|
Reasons for stem cell use |
They can help cure diseases like Parkinsons or paralysis They can differentiate into lost of different cells Large numbers can be grown in a laboratory |
|
|
Reasons against stem cell use |
Some say embryonic stem cells are unethical Collecting and growing stem cells is expensive Patients may need to take drugs for the rest of their life to prevent rejection |
|
|
What are meristem cells? |
Stem cells are found here and it is where growth occurs because the stem cells can differentiate into any type of plant cell |
|
|
Uses of stem cells in plants |
To produce clones of a plant quickly and cheaply. Produce more plants of a rare species. Produce more plants with a desired feature for farmers |
|
|
What is therapeutic cloning? |
Where the nucleus of a patients cell and an empty egg cell are fused together to create an embryo which can undergo mitosis. from this embryo, the stem cells can be used to differentiate into specific cells and grow tissues. |
|
|
What is binary fission? |
The way that prokaryotic cells divide. |
|
|
Stages of binary fission |
The circular DNA and plasmid(s) replicate The cell gets bigger and the DNA moves to opposite poles of the cell The cytoplasm starts to divide and a new cell wall starts to form There are now two daughter cells, they each have one copy of the circular DNA but can have varying numbers of plasmid(s) |
|
|
What is diffusion? |
The movement of particles from an area of high concentration to an area of low concentration. Down a concentration gradient |
|
|
What speeds up the rate of diffusion? |
A bigger concentration gradient Increase temperature as the particles have more kinetic energy to move If its through a membrane, a larger surface area |
|
|
What is a passive process? |
A process that doesn't involve energy |
|
|
What is osmosis? |
The diffusion of water from an area of high concentration to an area of low concentration through a semipermeable membrane |
|
|
How do you work out percentage change? |
percentage change=final value-original value ÷ original value X 100 |
|
|
What is active transport? |
When diffusion can't occur. The movement of particles from an area of low concentration to an area of high concentration against the concentration gradient. It requires energy from respiration. |
|
|
Examples of diffusion |
Breathing, digestion, placenta, roots |
|
|
Examples of osmosis |
Roots, cells of plants |
|
|
Examples of active transport |
Digestion, roots |
|
|
How are alveoli adapted for diffusion? |
Large surface area Moist lining to absorb gases Good network of capillaries for blood supply Thin walls |
|
|
How are villi adapted for diffusion and active transport? |
Single layer of surface cells They increase the small intestines surface area Good network of capillaries for blood supply |
|
|
How are leaves adapted for diffusion? |
Large surface area- flat leaf shape Stomata give spaces to diffuse through Stomata are controlled by guard cells |
|
|
How are gills adapted for diffusion? |
Gill filaments increase surface area Gill filaments are covered in lamellae which further increase surface area Lamellae have lots of blood capillaries Thin surface layer of cells |
|
|
Cell organisation from smallest to largest |
cell, tissue, organ, organ system, multi cellular organism |
|
|
What is a tissue? |
A group of similar cells that work together to complete a certain function. These can include more than one type of cell |
|
|
What is an organ? |
A group of different tissue that work together to perform a certain function |
|
|
What is an organ system? |
A group of organs working together to complete a certain function |
|
|
Enzyme. What it is and what its made from? |
A biological catalyst that speeds up a reaction without being changed or used up. Its a protein molecule made from chains of amino acids |
|
|
What is the lock a key model? |
All enzymes have an active site that is specific to a substrate and will only catalyse that reaction. The enzyme and substrate fit together which catalyses the reaction. The enzyme is unchanged and can be reused |
|
|
What is the induced fit? |
Where an enzyme changes shape slightly to get a tighter fit with the substrate |
|
|
Two things effecting the rate of enzyme catalysing reactions |
pH and temperature |
|
|
What is the effect of temperature on enzymes |
As the temperature increase the rate of reaction increases but if it gets too hot, some of the bonds holding the enzyme together break changing the shape of the active site. This means the substrate can't fit in so the enzyme is denatured. |
|
|
What is the effect of pH on enzymes? |
If its too high or too low, the pH affects the bonds holding the enzyme together, changing the shape of the active site and therefore denaturing the enzyme. |
|
|
What is meant by the optimum temperature or pH of an enzyme? |
The temperature or pH the enzyme works best at |
|
|
Why are enzymes important in digestion? |
They break down large insoluble molecules into smaller soluble molecules that can pass through the walls of the digestive system |
|
|
Where is amylase made? |
Small intestines Pancreas Salivary glands |
|
|
Where is protease made? |
Small intestines Pancreas Stomach |
|
|
Where is lipase made? |
Small intestines Pancreas |
|
|
Amylase breaks what down into what? |
Breaks starch down into sugars |
|
|
Protease breaks what down into what? |
Breaks protein down into amino acids |
|
|
Lipase breaks what down into what? |
Breaks lipids down into fatty acids and glycerol |
|
|
Where is bile made? |
In the liver |
|
|
Where is bile stored? |
In the gall bladder |
|
|
What does bile do? |
Bile neutralises stomach acid and makes the conditions alkaline. Emulsifies fat into tiny droplets |
|
|
What type of acid is stomach acid? |
Hydrochloric acid |
|
|
Why are fats emulsified? |
It increases the surface area of the fat so gives a larger area for the lipase to work on |
|
|
What does the mouth do in digestion? |
Chews the food to increase surface area and amylase is release from the salivary glands to break starch to glucose |
|
|
What does the oesophagus do in digestion? |
Rings of muscles contract in waves in a process called peristalsis to push food to the stomach |
|
|
What does the stomach do in digestion? |
Muscles contract to churn food Produces protease called pepsin Produces hydrochloric acid to kill bacteria and provide the right conditions (pH 2) for protease |
|
|
What does the liver do in digestion? |
Produces bile which neutralises stomach acid providing the right conditions for the small intestines and emulsifies fat. |
|
|
What does the gall bladder do in digestion? |
Where bile is stored before being released into the small intestines |
|
|
What does the pancreas do in digestion? |
Produces amylase, protease and lipase. Releases these into the small intestines. |
|
|
What does the small intestines do in digestion? |
Bile mixes here. More amylase, protease and lipase are produced. Digested food is absorbed from the small intestines to the bloodstream. |
|
|
What does the large intestines do in digestion? |
Water gets reabsorbed into the body. Squeezes remaining indigestible food into a solid mass (faeces) |
|
|
What does the rectum do in digestion? |
Stores faeces before leaving through the anus. |
|
|
What is peristalsis? |
Contracting and relaxing of muscles in a wave like motion. |
|
|
Test for sugars: chemical and colour if present |
Benedicts and turns from blue to green, yellow or brick red |
|
|
Test for starch: chemical and colour if present |
Iodine and turns from orange blue/black |
|
|
Test for protein: chemical and colour if present |
Biuret and turns from blue to pink/purple |
|
|
Test for lipids: chemical and colour if present |
Sudan III and forms a bright red layer on top |
|
|
What is the thorax? |
The top part of your body |
|
|
What is the trachea? |
The air you breathe in goes through here |
|
|
Path of air coming into the blood |
Mouth, trachea, bronchus, bronciole, alveoli, blood |
|
|
What is the alveoli? |
Where gas exchange happens |
|
|
Concentration of oxygen and carbon dioxide inside the alveoli |
High concentration of oxygen, low concentration of carbon dioxide |
|
|
Concentration of oxygen and carbon dioxide in blood near alveoli |
Low concentration of oxygen, high concentration or carbon dioxide |
|
|
Where does oxygen diffuse in the body? |
From alveoli to the blood and from the blood to cells |
|
|
Where does carbon dioxide diffuse in the body? |
From body cells to the blood, from the blood to the alveoli |
|
|
What is the circulatory system? |
Carry food and oxygen to every cell in our body. Also carries waste products to a place where they can be removed |
|
|
What type of tissue mostly makes the heart? |
Muscle tissue |
|
|
Function of heart valves |
To make sure blood flows in the right direction, they prevent it flowing backwards (backflow) |
|
|
Path of blood in heart |
Vena cava, right atrium, valve, right ventricle, valve, pulmonary artery, lungs, pulmonary vein, left atrium, valve, left ventricle, valve, aorta |
|
|
Which half of the heart is bigger and why? |
The left side if bigger as it needs to pump blood to the whole body. the right side only has to pump to the lungs |
|
|
What are coronary arteries? |
Arteries that provide the heart tissue with oxygen |
|
|
Where are the pacemaker cells and what do they do? |
They are found in the right atrium and they produce small electrical impulses that cause the muscle cells in your heart to contract |
|
|
What are artificial pacemakers? |
Used for patients whose natural pacemaker cells don't work properly. |
|
|
Arteries: function and adaptations |
To carry blood at high pressure away from the heart. The have thick walls compared to their small lumen, Thick layers of muscles and elastic fibres so they can stretch and spring back |
|
|
Veins: function and adaptations |
To carry low pressure blood back to the heart. They have a large lumen to help the flow of blood, valves to keep the blood flowing in the right direction |
|
|
Capillaries: function and adaptations |
Involved in the exchanged of materials at the tissues. Very thin walls (one cell thick), permeable walls so substances can diffuses in and out, tiny so they can carry blood really close to every cell |
|
|
4 main things in blood |
Red blood cells White blood cells Platelets Plasma |
|
|
What are platelets? |
These are small fragments of cells floating in your plasma. They help your blood clot by forming a mesh so that blood can't pour out and pathogens can't get in. |
|
|
What is plasma? |
A pale straw coloured liquid that carries everything in your blood |
|
|
What does plasma carry? |
Red blood cells White blood cells Hormones Glucose Urea Proteins Carbon dioxide Antibodies and antitoxins |
|
|
What is cardiovascular disease? |
Disease of the heart or blood vessels |
|
|
What is coronary heart disease? |
When the coronary arteries that provide the heart with oxygen rich blood get blocked by fatty deposits. This causes the artery to be narrowed and blood flow to be reduced. |
|
|
What are stents? |
Tubes inserted inside an artery that pushes the fatty deposit to the edges and therefore widens the artery and increases blood flow |
|
|
Benefits of stents |
Recovery time is quick Lowers the risk of heart attack Effective for a long time Quick surgery |
|
|
Disadvantages of stents |
Risk of heart attack during the operation Risk of infection Risk of developing a blood clot near the stent (thrombosis) |
|
|
What is thrombosis? |
A blood clot |
|
|
What are statins? |
Reduce the 'bad' cholesterol from your blood so slows down the formation of fatty deposits |
|
|
What is cholesterol? |
An essential lipid that your body needs to function properly. However if you have too much LDL cholesterol, fatty deposits may form |
|
|
Advantages of statins |
They can reduce the risk of stroke, coronary heart disease and heart attack They increase the amount of 'good' HDL cholesterol which can remove bad cholesterol studies suggest they may help prevent other diseases |
|
|
Disadvantages of statins |
They are a long term drug that must be taken regularly They can sometimes cause negative side effects The effect isn't instant. It takes time to kick in |
|
|
Advantages of artificial hearts |
They can keep a person alive while they are waiting for a donor They are less likely to be rejected by the patient |
|
|
Disadvantages of artificial hearts |
Surgery can lead to bleeding and infection They don't work as well as healthy natural ones as parts could wear out or the motor could fail Blood doesn't flow through them as easily causing blood clots or stroke The patient has to take blood thinning drugs |
|
|
Two types of valve replacement |
Mechanical or biological |
|
|
What is artificial blood? |
A blood substitute used to replace the lost volume or blood. This may give the patient enough time to produce new red blood cells |
|
|
What is meant by health? |
The state of physical and mental well being |
|
|
What is a communicable disease? |
A disease that can be spread from person to person or between humans and animals. |
|
|
What is a non-communicable disease? |
A disease that cannot be spread from person to person or between humans and animals |
|
|
What are carcinogens? |
Cancer causing chemicals |
|
|
Problems associated with being underweight |
Fertility problems Heart problems Osteoporosis |
|
|
Problems associated with being overweight |
Type 2 diabetes Heart problems Cancers Stroke Arthritis |
|
|
How is cancer caused? |
When there is a mutation in the DNA of a cell which becomes damaged. When this cell divides out of control a tumour is formed |
|
|
Two types of tumour |
Benign and malignant |
|
|
What is a benign tumour? |
This tumour grows until there is no more room. It stays in one place and doesn't invade other tissues. It isn't normally dangerous and it's not cancerous |
|
|
What is a malignant tumour? |
This tumour grows and spreads to healthy tissue. Parts can break off and spread to other parts of the body to form secondary tumours. These are dangerous and can be fatal, they are cancerous |
|
|
Lifestyle factors that increase the risk of cancer |
UV exposure Smoking Obesity Viral infection |
|
|
What is epidermal tissue? |
Tissue that covers the whole plant |
|
|
What is palisade tissue? |
Where more photosynthesis happens. They have lots of chloroplasts and are near the top of the leaf |
|
|
What is the function of the spongy mesophyll? |
Contains large air spaces to allow gases to diffuse in and out of cells |
|
|
What is the function of the waxy cuticle? |
Reduces water loss by evaporation |
|
|
What is the function of the upper epidermis? |
Transparent so light can get through to the palisade layer |
|
|
What is transpiration? |
The loss of water from a plant normally in the leaves. This is through diffusion and evaporation |
|
|
What is the transpiration stream? |
As water is loss through transpiration at the leaves, a slight shortage is created to water is drawn up through the xylem to replace it. This means more water is drawn up through the roots creating a constant transpiration stream |
|
|
What is translocation? |
The process of food substances being transported around the plant |
|
|
4 things that effect transpiration rate |
Light intensity Temperature Air flow Humidity |
|
|
How does light intensity effect transpiration rate? |
When there is more light, the stomata open so water can be loss. When it is dark, the stomata start to close as photosynthesis can't happen at night and CO2 doesn't need to be let in |
|
|
How does temperature effect transpiration rate? |
When it is warmer, the water particles have more energy to diffuse and evaporate out of the stomata |
|
|
How does air flow effect transpiration rate? |
If air flow around the leaf is poor, the water vapour surrounds the leaf. If there's a high concentration of water outside the leaf as well as inside, diffusion will be slower. If there's a good air flow, particles will be moved away easier maintaining a low concentration outside |
|
|
How does humidity effect transpiration rate? |
If the air is moist outside of the leaf, there isn't a low concentration so diffusion happens slower. If it is drier, there is a bigger concentration gradient |
|
|
What is a potometer? |
Measures the uptake of water from a plant which is directly related to water loss- transpiration |
|
|
How do the guard cells and stomata work? |
When the leaf has a lot of water, the cell becomes turgid which opens the stomata so gases can be exchanged for photosynthesis. When the leaf has little water, the guard cells become flaccid so the stomata close preventing against water loss. they also close at night as photosynthesis can't be carried out at night. |
|
|
4 types of pathogen |
Fungi, bacteria, virus and protist |
|
|
What do bacteria do? |
Make you feel ill by producing toxins |
|
|
What do viruses do? |
Make you feel ill by damaging cells as they reproduce |
|
|
What do protists do? |
Cause damage to organisms by living on or in other organisms |
|
|
What do fungi do? |
Grow and penetrate skin of human and plants causing disease |
|
|
3 ways pathogens can be spread |
Air, water, direct contact |
|
|
Examples of viruses |
Measles, influenza, HIV, TMV |
|
|
Examples of bacteria |
Salmonella, Gonorrhoea |
|
|
Example of fungi |
Rose Black spot, athletes foot |
|
|
Example of protist |
Malaria |
|
|
4 ways to prevent disease |
Vaccinations, being hygienic, isolating individuals, destroying vectors |
|
|
What is phagocytosis? |
When phagocytes engulf and digest pathogens |
|
|
3 ways white blood cells fight against pathogens |
Consuming them, producing antibodies, producing antitoxins |
|
|
What are B-lymphocytes? |
These are the white blood cells that produce antibodies and antitoxins |
|
|
How do B-lymphocytes work? |
If they find an antigen they recognise as foreign, they start to produce antibodies that lock onto the pathogens destroying it or clumping them together so phagocytes can engulf them |
|
|
What do antitoxins do? |
They counteract the toxins produced by pathogens |
|
|
What is a vaccination? |
Small amount of dead or weakened pathogens that force your immune system to produce antibodies to attack them. |
|
|
How do vaccinations prevent against future attack? |
Once your body has already produced the antibody for the specific antigen, the next time the pathogen attacks, your body can make the antibody quicker and in a higher quantity |
|
|
Pros of vaccinations |
They help control diseases Many can be immune to certain diseases They help prevent epidemics |
|
|
Cons of vaccinations |
They don't always work Some can have a bad reaction to them |
|
|
How do bacteria become resistant to antibiotics? |
The bacteria can mutate to survive making them resistant to the antibiotic |
|
|
Aspirin: What does it treat and where is it from? |
Painkiller and comes from willow bark |
|
|
Digitalis: What does it treat and where is it from? |
Heart disease and comes from foxgloves |
|
|
What type of pathogen is malaria? |
Protist |
|
|
What are sporozoites? |
Produced from gametocytes in the mosquito's stomach. They move to the salivary glands where they are injected into the human when the mosquito has a blood meal. They go to the liver cells where they asexually reproduce forming merozoites |
|
|
What are merozoites? |
Produced in the liver, travel to red blood cells where they form schizonts that burst the red blood cell releasing merozoites and gametocytes |
|
|
What are gametocytes? |
Ingested when the mosquito has a blood meal, travel to the mosquito's stomach where they reproduce by meiosis making sporozoites. |
|
|
Stages of drug testing |
Tested on cells and tissues Tested on mammals for toxicity Tested on healthy volunteers, some will have a placebo to check for true side effects Tested on people with the disease Large scale trial |
|
|
What is a hybridoma? |
Fused mouse B-lymphocyte and tumour cell |
|
|
How are monoclonal antibodies made? |
Mouse injected with antigen, mouse creates antibody and the b-lymphocytes are collected Mouse b-lymphocyte fused with tumour cells to help division. This is a hybridoma. Hybridomas are cloned to get identical cells which all produce the same antibodies The antibodies are collected and purified
|
|
|
Why are monoclonal antibodies useful? |
They are specific to only one antigen so they can be used to target one cell or chemical in the body. |
|
|
What can monoclonal antibodies be used for? |
Pregnancy tests, treating cancer, finding levels of hormones/chemicals in blood, finding pathogens in blood, locate specific molecules in cells or tissues |
|
|
How are monoclonal antibodies used to find specific substances like hormones or pathogens? |
Monoclonal antibodies are made for the specific thing you are looking for A fluorescent dye is added to the monoclonal antibodies When they find the specific molecule they can be traced using the dye |
|
|
Disadvantages of monoclonal antibodies |
They can cause vomiting, fever and low blood pressure |
|
|
3 things that can be bound to a monoclonal antibody to treat cancer |
Radioactive substance, toxic drug, chemical that stops the cancer cells growing and dividing |
|
|
What do plants need other than water? |
Mineral ions |
|
|
Nitrates: use and what a lack of causes |
Used for protein making so therefore growth, lack of caused stunted growth |
|
|
Magnesium ions: use and what a lack of causes |
Used for making chlorophyll needed for photosynthesis, lack of causes chlorosis and yellow leaves |
|
|
What is chlorosis? |
Lack of green colouration in leaves making them yellowy |
|
|
Measles: type, spread by, effect |
Virus, spread by droplets from sneezes and coughs, redskin rash and fever |
|
|
HIV: type, spread by, effect
|
Virus, spread by sexual contact or sharing blood, initially get fever symptoms then effects the immune system |
|
|
TMV: type, spread by, effect |
Tobacco mosaic virus, virus, spread by direct contact usually through human handling, mosaic pattern on the leaves and discolouration meaning plants can't carry out photosynthesis as well so growth is affected |
|
|
Rose black spot: type, spread by, effect |
Fungus, spread by water and wind, purple/black spots on leaves that turn yellow and drop of meaning they can't carry out photosynthesis as well. |
|
|
How is rose black spot treated? |
By using fungicides and removing and destroying the effected leaves |
|
|
Malaria: type, spread by, effect |
Protist, spread by mosquitoes, repeating episodes of fever |
|
|
Salmonella: type, spread by, effect |
Bacteria, eating contaminated food, fever, vomiting, stomach cramp and diarrhoea |
|
|
Gonorrhoea: type, spread by, effect |
Bacteria, sexual contact, pain when urinating and thick yellow/green discharge from penis or vagina |
|
|
5 ways plants can be damaged |
Virus, bacteria, fungus, insect infestations, mineral ion deficiency |
|
|
6 signs of plant disease |
Stunted growth, abnormal lumps, discolouration, spots on leaves, malformed stems or leaves, areas of decay |
|
|
How do you spot insect infestations? |
You should see the insect on the plant |
|
|
3 ways to identify the plant disease |
Looking up the symptoms, allowing scientists to identify the pathogen, using a testing kit with monoclonal antibodies |
|
|
3 categories of plant defenses |
Physical, chemical and mechanical |
|
|
Examples of physical defenses |
Waxy cuticle layer on leaves, cell wall made from cellulose layers of dead cells around their stems |
|
|
Examples of chemical defenses |
Producing antibacterial chemicals like witch hazel, producing poisons to deter herbivores |
|
|
Examples of mechanical defenses |
Thorns or hairs to stop animals touching and eating, leaves drooping or curling, mimicking other organisms for example looking like they have eggs on them or looking like stones |
|
|
What happens during photosynthesis? |
Carbon dioxide and water are transferred into glucose and oxygen using light energy |
|
|
Is photosynthesis exothermic or endothermic? |
Endothermic |
|
|
Word equation for photosynthesis |
........................................light carbon dioxide + water --> glucose + oxygen |
|
|
Symbol equation for photosynthesis |
.......................light 6cO2 + 6H2O --> C6H12O6 + 6O2 |
|
|
4 limiting factors of photosynthesis |
Light intensity Concentration of carbon dioxide Temperature Chlorophyll |
|
|
2 things that effect the amount of chlorophyll |
Disease like TMV or environmental stress like lack of mineral ions |
|
|
5 uses of glucose |
For respiration- glucose are transferred into energy Making amino acids- glucose mixes with nitrates to make amino acids which then make protein Stored as starch- turned into starch and stored in the roots, stems and leaves for when photosynthesis isn't happening Stored as oils or fats- turned into lipids for storing in seeds Making cellulose- converted to cellulose to make strong cell walls |
|
|
Explain the graph for light intensity and rate of photosynthesis |
As the light intensity is raised, the rate of reaction rises steadily to a certain point. The graph then flattens out even though the light intensity is still rising. This is because the light intensity is no longer the limiting factor and the concentration of CO2 or temperature is now the limiting factor |
|
|
Explain the graph for concentration of CO2 and rate of photosynthesis |
As the concentration is raised the rate of photosynthesis increases steadily to a certain point. The graph then flattens out even though the concentration is still increasing. This is because the concentration is no longer the limiting factor and light intensity or temperature is. |
|
|
Explain the graph for temperature and rate of photosynthesis |
As the temperature is raised the rate of photosynthesis increases because the enzymes needed for photosynthesis work quicker at higher temperatures. At about 45°C however the temperature gets too hot and the enzymes become denatured so the rate of photosynthesis decreases. |
|
|
Equation linking light intensity to distance |
light intensity ∝ 1/distance² |
|
|
What is respiration? |
The process of transferring energy from glucose which is a process going on in every cell. |
|
|
Is respiration exothermic or endothermic? |
Exothermic |
|
|
3 ways organisms use energy from respiration |
To build up larger molecules from smaller molecules In animals it allows muscles to contract In mammals and birds it allows body temperature to be kept steady in the cold |
|
|
What is metabolism? |
All the chemical reactions in an organism |
|
|
What is aerobic respiration? |
Respiration using oxygen |
|
|
What is anaerobic respiration? |
Respiration used when there is not enough oxygen |
|
|
Aerobic respiration equation (word and symbol) |
Glucose + oxygen --> carbon dioxide + water C6H12O6 + 6O2 --> 6CO2 + 6H2O |
|
|
Word equation for anaerobic respiration in humans |
Glucose --> lactic acid |
|
|
When is aerobic respiration used in humans? |
When doing exercise and your body can't supply enough oxygen to your muscles you start doing anaerobic respiration as well as aerobic respiration |
|
|
Word equation for anaerobic respiration in plants and yeast |
Glucose --> ethanol + carbon dioxide |
|
|
What is fermentation? |
Anaerobic respiration in yeast |
|
|
What is fermentation used for? |
To produce bread (the CO2 helps it rise) and producing alcoholic drinks (ethanol is alcohol) |
|
|
3 things that happen when you start doing exercise |
Breathing rate increases, breath volume increases, heart rate increases |
|
|
Why does your breathing rate and breath volume increase during exercise? |
To get more oxygen into the blood for increased respiration |
|
|
Why does your heart rate increase during exercise? |
To get oxygenated blood round the body quicker and to remove CO2 quicker |
|
|
What is oxygen debt and why do you have it? |
Oxygen debt is the amount of oxygen your body needs to remove the lactic acid from your muscles. You have it because your lungs heart and blood couldn't keep up with the demand earlier. |
|
|
What does oxygen and lactic acid make? |
CO2 and water |
|
|
How does your liver help remove lactic acid? |
Blood transports the lactic acid to your liver where is it converted back into glucose |
|
|
What temperature must you set the water bath to for benedicts solution? |
75°c |
