7 Ecology Seperate

Question 1

State the three environmental factors that can cause a change in the distribution of organisms.

Answer 1

Water availability, temperature, (dissolved) atompsheric gases concentration

Question 2

Give three possible reasons to changes in environmental factors.

Answer 2

Seasonal changes, geographical changes, result of human interaction

Question 3

Suggest one positive change on the environment due to human interaction.

Answer 3

Maintain rainforests / Reduce water pollution and monitor pH / Restrict entry to protected areas / Conservation measures

Question 4

Suggest one negative impact on the environment due to human interaction.

Answer 4

Global warming and climate change / Acid rain / Pollution

Question 5

Suggest how organisms may adapt to seasonal changes.

Answer 5

Migrate to areas with more ideal conditions

Question 6

Define ‘trophic level’.

Answer 6

Position of organisms within a food chain

Question 7

What kinds of organisms are in trophic levels 1 and 4 respectively?

Answer 7

1: Producers; 4: Tertiary consumers

Question 8

State the name given to carnivores with no predators above their level.

Answer 8

Apex predators

Question 9

How do decomposers break down organic matter?

Answer 9

Secrete enzymes into the environment –> absorb small soluble food molecules back in through diffusion

Question 10

What needs to be done to an organism in order to measure its biomass?

Answer 10

Kill it + dry them out

Question 11

What is a problem with measuring wet biomass?

Answer 11

Water levels vary throughout the day and dependent on conditions –> less repeatable results

Question 12

State the original source of all biomass.

Answer 12

Photosynthesis

Question 13

Which trophic level is always at the bottom of the pryamid of biomass?

Answer 13

Trophic level 1 (producers)

Question 14

What happens to the amount of biomass at each trophic level as we go up the food chain?

Answer 14

Decreases

Question 15

Give three reasons why biomass always decreases as we go up the trophic levels.

Answer 15

1. Not whole/part of organisms are eaten; 2. Some biomass taken in is passed out and lost as waste; 3. Most biomass taken in is used up in respiration, only some used to build new biomass

Question 16

What is incident energy?

Answer 16

All the energy from the sunlight falling on Earth

Question 17

Approximately how many percent of the incident energy is used by producers to do photosynthesis?

Answer 17

1%

Question 18

Approximately how many percent of the biomass from each trophic level is transferred to the next?

Answer 18

10%

Question 19

Why cannot herbivores digest all the plant material they eat?

Answer 19

Most herbivores lack enzymes to digest cellulose

Question 20

Why cannot carnivores eat all of their prey?

Answer 20

Some parts are impossible to digest (eg. bones, claws)

Question 21

What is made from excess amino acids to be excreted as waste?

Answer 21

Urea

Question 22

What are the three waste products from respiration?

Answer 22

Carbon dioxide, water, heat

Question 23

Explain why the more movement an animal does, the more biomass it loses.

Answer 23

More movement requires more respiration to provide more energy for muscle contraction, hence less biomass available to build new biomass

Question 24

Explain why mammals need to eat more food than amphibians to achieve the same increase in biomass.

Answer 24

Mammals need to use biomass constantly to maintain body temp regardless of surroundings, whereas amphibians can change their body temp according to surroundings, so for them more biomass is used to build new biomass (less wasted compared to mammals)

Question 25

State the four ways in which biomass can be lost from an animal.

Answer 25

1. Through faeces; 2. Through urine; 3. To provide energy for movement; 4. Heat loss from respiration to surroundings

Question 26

What is meant by ‘food security’?

Answer 26

Having enough food to feed a population

Question 27

State a consequence from low or lack of food security.

Answer 27

Malnutrition/starvation

Question 28

State three factors that affect food security.

Answer 28

Increasing birth rates / Changing diets / New pests and pathogens affecting farming / Environmental changes affecting food production / Cost of agricultural inputs / Conflicts affecting access to food and water

Question 29

How can a change of diet in developed countries threaten food security?

Answer 29

More scarce food resources delivered to developed countries, depriving local people (usually in developing countries) of their food source

Question 30

How does climate change affect farming?

Answer 30

Droughts and flooding destroy crops and damage farmlands (no fertile soil)

Question 31

What is sometimes fed to livestock to increase their growth?

Answer 31

High protein food (eg. other animals)

Question 32

Why would reducing the stages in the food chain dramatically increase the efficiency of our food production?

Answer 32

Less biomass/energy lost

Question 33

State two methods farmers use to increase the efficiency of food production.

Answer 33

1. Limit animals’ movement; 2. Control temperature of surroundings

Question 34

Explain why limiting livestocks’ movement could improve the efficiency of food production.

Answer 34

Less movement hence less biomass used up in respiration for muscle contraction

Question 35

Explain why controlling the temperature of the surroundings can improve the efficiency of food production.

Answer 35

Less biomass used in respiration to maintain body temperature

Question 36

Suggest a disadvantage to limiting livestocks’ movement.

Answer 36

Risk of disease spreading quickly

Question 37

What is meant by sustainable food production?

Answer 37

The idea to produce food that ensures there is still good quality food available for future generations

Question 38

What is the problem with overfishing?

Answer 38

No more younger fish to grow and reproduce to replace them in the future –> low fish stocks

Question 39

Describe two ways to conserve fish stocks at a sustainable level.

Answer 39

1. Control net sizes (larger); 2. Introduce fish quotas and season bans

Question 40

What is the role of biotechnology in food production?

Answer 40

Culture genetically engineered microorganisms to produce large quantities of food

Question 41

What is mycoprotein?

Answer 41

Protein made by fungus

Question 42

Name the fungus that can be used to produce mycoprotein.

Answer 42

Fusarium

Question 43

What are the two requirements for the fungus to grow to produce mycoprotein?

Answer 43

Glucose syrup + Aerobic conditions

Question 44

State an advantage in using fungi as a renewable food source.

Answer 44

Cheap raw material to feed fungi / Reproduce rapidly

Question 45

State an advantage in using genetically modified crops.

Answer 45

Provide more food / food with better nutritional value