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B4 Revision Cards
Question | Answer |
---|---|
What is biodiversity? | The variety of different species living in a habitat. |
What is the difference between an ecosystem and a habitat? | A habitat is where a plant or animal lives. An ecosystem is the interaction between the abiotic and biotic factors that are present. |
What is the difference between a community and a population? | A population is all the organisms of the same kind living in the same place, a community is all the populations living in one place. |
Which has more biodiversity - natural or artificial ecosystems? | Natural ecosystems like native woodlands and lakes. |
What is the word equation for photosynthesis? | Carbon Dioxide + Water = Oxygen and Glucose 6co2+6hy2o= 6o2+c6h12o6 |
How is glucose stored in plants? | As insoluble starch - this can be tested for with iodine. |
When do plants carry out respiration? | All the time - thats how they get energy to grow. |
Give four ways plants use glucose. | For energy in respiration, growth and repair, making cellulose cell walls and for storage as fats and starch. |
Name the limiting factors of photosynthesis | Carbon dioxide, light and temperature. |
Why is starch a good storage molecule? | It is insoluble in water and does not affect the concentration of a cell. It will not affect osmosis. |
Explain how leaves are adapted for efficient photosynthesis. | Broad, thin, waterproof transparent epidermis top layer, stomata to allow CO2 to enter, a palisade layer with lots of chloroplasts to absorb light. |
Give a definition of diffusion | When particles randomly move from an area of high concentration to low concentration, until the concentrations even out. This does not require energy. |
When is the rate of diffusion increased? | When there is a shorter distance, a greater concentration gradient and a greater surface area. |
Give a definition of osmosis | When water particles randomly move from an area of high water concentration to low water concentration, until the concentrations even out. This does not require energy. |
How does osmosis affect a plant cell? | It allows cells to take in water. When they become turgid they stiffen and hold their shape. When they lose water they become flaccid and limp.(Wilt) |
How would dilute blood and osmosis affect a red blood cell? | It would absorb water and burst as RBCs do not have a cell wall. |
Where does the oxygen for glucose come from? | Carbon dioxide, the oxygen in water is released by the plant as a product of photosynthesis. |
Four factors that increase the rate of transpiration. | Light intensity, increased temperature, increased air movement and decreased humidity |
Four reasons why transpiration is important. | For cooling a plant, photosynthesis, support and movement of minerals. |
What is transpiration? | The evaporation and diffusion of water out of leaves. |
How is a leaf adapted to reduce water loss? | It has a waxy cuticle and only a small number of stomata on the upper surface. |
Four minerals in fertilisers. | Nitrates, phosphates. potassium and magnesium. |
Why are nitrates important to plants? | To make proteins for growth and repair. |
How do plants take in minerals at their root hair cells. | By active transport, the opposite of diffusion. This requires energy from respiration. |
How are root hairs adapted for their function? | They are long and have a large surface area for absorption. |
List four factors that are important in decay. | Temperature, oxygen, water and the presence of microorganisms |
Six examples of how to preserve food from decay. | Canning, cooling, freezing, drying, adding salt or sugar and adding vinegar. |
what do all basic processes of life carried out by all living things depend on? | chemical reactions within cells that require energy released by respiration |
what is the lock and key model? | it is where a molecule has to be the correct shape to be able to fit into the active shape of an enzyme |
what happens if it is to hot for the molecule to go into the enzyme | it will denature |
what do enzymes do? | they speed up chemical reaction |
how do cells make enzymes? | they make them according to the instuctions carried in genes |
what can an increase of temperature do to an enzyme? | if it only a little higher it can speed up the reaciotn |
enzymes need an optimum | ph and temperature |
what are the main stages of photosynthesis? | light energy absorbed by the chemical chlorophyll,energy used to bring about the reaction between carbon dioxide (co2) and water (h2o) to produce glucose (c6h12o6), oxygen (o2) produced as a waster product |
what can glucose be converted into? | starch for storage |
where are minerals taken up by? | from plant roots to make some chemicals needed by the cells |
what is the movement of oxygen and co2 controlled by? | diffusion |
how to take a transect? | A transect is line across a habitat or part of a habitat. It can be as simple as a string or rope placed in a line on the ground. The number of organisms of each species can be observed and recorded at regular intervals along the transect |
what reactions to living organisms need that have released by respiration | movement,synthesis of large molecule,active transport |
aerobic respiration | c6h1206+6o2=6co2+6h2o glucose+oxygen=carbon dioxide+water |
anaerobic respiration in animals | glucose=lactic acid(+energy released) |
anaerobic respiration in plant cells | glucose=ethanol+carbon dioxide(+energy released) |
what it the structure of a typical animal and microbial cell limited to? | nucleus,cytoplasm,cell membrane,mitochondria (for animals and yeast),cell wall(for yeast and bacterial) circular DNA molecule(for bacteria cells) |
what do mitochondrion do? | it contains an enzyme for aerobic respiration |