Ecosystem

Question 1

1. What does ‘mineral deficiency’ mean?
2. Why do some farmers spray their crops with fertiliser?

Answer 1

1. A lack of specific minerals needed by a plant
2. To add essentiall minerals for plant growth;

Nitrogen- for amino acids

Phosphorus- for roots and leaves

Potassium- for healthy leaves

Question 2

Explain to a sprinter why they use anaerobic respiration during a race but marathon runners use aerobic respiration.

Answer 2

A sprinter will need energy fast and therefore use up the oxygen available in their blood. They do not have enough time to breathe in more oxygen and therefore will carry out anaerobic respiration when the oxygen runs out. They must replace this oxygen debt by breathing in heavily after their race.

A marathon runner is breathing in and out constantly to take in lots of oxygen and release the waste carbon dioxide.

Question 3

1. Where does respiration take place in a cell?
2. Name 2 differences between anaerobic and aerobic respiration:

Answer 3

1. In the mitochondria

Aerobic requires oxygen and also produces large amounts of chemical energy.

Anaerobic respiration does not require oxygen and releases less energy.

Question 4

Describe the similarities and differences between food chains and food webs.

Answer 4

Food chains are a description of one organism eating another

Food webs describe many food chains and interactions.

Both types will move from the producer through to top carnivore.

Question 5

Complete the word equation for anaerobic respiration:

Answer 5

Glucose → Lactic acid + Energy (ANIMALS)

Glucose →Ethanol + Carbon dioxide + energy (FERMENTATION in plants and yeast)

Question 6

Complete the word equation for aerobic respiration:

Answer 6

Glucose + Oxygen → Carbon dioxide + water

Question 7

Label the main parts of the leaf and explain how it is adapted for photosynthesis to happen.

Answer 7

Question 8

Can you write down for photosynthesis:

1. word equation
2. symbol equation
3. balanced symbol equation

Answer 8

Word: Carbon dioxide + water → glucose + Oxygen

Symbol: CO2 + H2O → C6H12O6 + O2

Balanced Symbol: 6CO2 + 6H2O → C6H12O6 + 6O2

Question 9

What does ‘interdependence’ mean?

Answer 9

Organisms live within the same environment and depend on each other to survive, grow and reproduce.

E.g. plants need bees to pollinate their flowers and bees need plants for food.

Question 10

What is ‘Chemosynthesis’? How is it different to ‘Photosynthesis’?

Answer 10

Chemosynthesis is the breakdown of chemicals within an organism to make glucose.

It is different to photosynthesis as there is no single equation to describe the process and light is not needed.

Chemosynthesis is usually carried out by bacteria.

Question 11

Think back to the experiment we did in class on aerobic respiration.

Describe this experiment and how exercise affects the rate of respiration. Include predictions of what you might have expected to observe.

Answer 11

Increased exercise increases:

1. Heart rate increases to take blood around the body.

2. Breathing rate increases to take in more oxygen to breakdown glucose for more energy.