Life Processes

Question 1

What is respiration

Answer 1

The process of breaking down glucose to release energy which happens in every living cell

Question 2

What is aerobic respiration

Answer 2

Respiration using oxygen

Glucose + oxygen -> carbon dioxide + water (+energy)

Question 3

What is diffusion

Answer 3

The movement of particles from an area of high concentration to an area of low concentration

Question 4

How does the body do respiration

Answer 4

The circulatory system carries glucose oxygen and carbon dioxide around the body in the blood
The glucose comes from breaking down food in the digestive system
The oxygen comes from air breathed into the lungs the substances move between the blood in capillaries and the muscles or lungs by diffusion

Question 5

Cardiac output =

Answer 5

Heart rate X stroke volume

Question 6

What Happens to our breathing when we exercise

Answer 6

The muscles need more energy therefor need more oxygen

The breathing rate increases to get more oxygen into the blood

Question 7

What is cardiac output

Answer 7

The volume of blood the heart pumps in on minute

Question 8

What is anaerobic respiration

Answer 8

It happens when there’s no enough oxygen

Glucose -> lactic acid (+energy)

Question 9

What does lactic acid do

Answer 9

It gets painful and causes cramp
It creates an oxygen debt so you have to repay it by EPOC so you keep on breathing hard after you stop exercising and the heart rate stays high so the toxic lactic acid can be converted to co2 and water

Question 10

What is photosynthesis

Answer 10

The process that produces food in plants
It happens in all green plants inside the chloroplasts

Carbon dioxide + water (+sun+chlorophyll)-> oxygen + glucose

Question 11

How are leaves adapted for photosynthesis

Answer 11

They are broad so there’s a large surface area to absorb the light
The chloroplasts are nearest to the edge of the cell
The stomata can open and close to allow gases such as co2 and oxygen to diffuse in and out of the cell and allow water vapour to escape

Question 12

How does light effect photosynthesis

Answer 12

Light provides energy for photosynthesis
As the light level increases the rate of photosynthesis also increases up to a certain point where it no longer effects the rate

Question 13

How does carbon dioxide effect photosynthesis

Answer 13

The concentration of co2 can increase the rate of photosynthesis up to a certain point the more co2 the more photosynthesis

Question 14

How does temperature effect photosynthesis

Answer 14

Enzymes needed for photosynthesis work too slowly at a low temperature so the rate won’t be fast if the temp is low
If it’s too hot the enzymes become denatured so the temperature has to be just right usually bell 45c

Question 15

What is osmosis

Answer 15

The movement of water molecules from an area of high water concentration to an area of low water concentration across a partially Permeable membrane

Question 16

What practical can you do to show osmosis

Answer 16

Cut a potato into identical cylinders and get some beakers with different sugar solutions one should be pure water and one very concentrated measure the length of the cylinders and leave them in the beaker for half an hour
Take them out and measure them if water has moved into the cylinders by osmosis then they will be longer this happened if the water content in the beaker is higher than the potato

Question 17

How do root hair cells take in water

Answer 17

They have a large surface area and stick out into the solid so they can effectively do osmosis

Question 18

How do root hairs absorb minerals from the soil

Answer 18

The concentration of minerals in the soil is usually lower than in the plant so active transport happens where they use energy to move the minerals into the plant against the concentration gradient

Question 19

What happens in the xylem

Answer 19

Water and minerals are transported from the root to the rest of the plant

Question 20

What happens in the phloem

Answer 20

Sugar is transported from the leaves to growing and storage tissues

Question 21

What happens in transpiration

Answer 21

When the water evaporates from the leaves so more water is drawn up through the xylem to replace the water lost
So there’s a constant transpiration stream of water through the plant for photosynthesis but it is a side effect of photosynthesis as well

Question 22

What is a habitat

Answer 22

A place where an organism lives

Question 23

What are pooters

Answer 23

They’re for collecting ground insects you suck up the short tube and out the long tube over the insect

Question 24

What are pitfall traps

Answer 24

They’re steep sided containers sunk into a hole in the ground the top is partly open and insects can come and fall into he container

Question 25

What are sweep nets

Answer 25

A net filled with strong cloth used to collect insects or spiders from long grass

Question 26

What are pond nets

Answer 26

It’s used to collect organisms from water e.g. Water snails

Question 27

What is a quadrat

Answer 27

You throw it into a random point and then count the organisms in each square and repeat
You can work out the mean number of organisms then compare to another mean

Question 28

How can you work out a population size

Answer 28

Work out the mean number per Quadrat and multiply by the total area