B1 5 Biomass

Question 0

What is biomass?

Answer 0

Biomass is the dry mass of living material in an animal or plant.

Question 1

What is the main source of energy for all living things?

Answer 1

Radiation from the sun (solar or light energy).

Question 2

Why is the amount of biomass at each stage of a food chain lass than it was at the previous stage?

Answer 2

• Not all organisms at one stage are eaten by the stage above • Some material and energy taken in is passed out as waste by the organism • Respiration and synthesis reactions of the organism

Question 3

What is a producer?

Answer 3

A producer can make complex compounds from simpler inorganic molecules.

Question 4

What is a herbivore?

Answer 4

A herbivore is an organism that only eats plants.

Question 5

What is a carnivore?

Answer 5

A carnivore is an animal that eats a diet consisting mainly of meat.

Question 6

Energy loss in waste:

Answer 6

• Some animals cannot digest all the parts of an animal that they eat, therefore some biomass is lost as faeces • When an animal eats more protein than it needs, the excess is broken down. It gets passed out as urea in urine

Question 7

Energy loss in movement:

Answer 7

• Parts of the biomass eaten by an animal is used for respiration inside its cells • Movement uses a great deal of energy, the muscles use energy to contract so biomass is lost by respiration of cells in the muscles

Question 8

Keeping a constant body temperature:

Answer 8

Animals use energy to maintain a constant body temperature. Animals use energy to keep warm or to cool down.

Question 9

What organism breaks down waste, dead animals and plants after they die?

Answer 9

Decomposers.

Question 10

What happens in the process of decomposition?

Answer 10

The nutrients and other minerals are returned to the environment. The same material is recycled over and over again.

Question 11

What are decomposers?

Answer 11

Decomposers are a group of micro organisms that include bacteria and fungi. They feed on waste droppings and dead organisms.

Question 12

What are detritus feeders?

Answer 12

Detritus feeders such as maggots and some types of worms often start the process of decay. They eat dead animals and produce waste materials. The bacteria and fungi then come in to digest everything. Some of the nutrients they receive are used for reproduction and growth while the rest is released as waste products.

Question 13

What are the waste products of decomposers?

Answer 13

Carbon dioxide, water and nutrients that plants use.

Question 14

Why is the decay process important?

Answer 14

The decay process is important as it releases substances that plants need to grow.

Question 15

Decay in warm/cold conditions:

Answer 15

Chemical reactions in micro organisms work faster in warm conditions. They slow down and might even stop if the conditions are too cold. However, in very hot conditions, the enzymes may denature and stop working.

Question 16

Decay in moist conditions:

Answer 16

Most micro organisms grow better in moist conditions. The moisture makes the micro organisms dissolve their food with ease and it also prevents the micro organisms from drying out.

Question 17

Decay with oxygen:

Answer 17

Most micro organisms need oxygen to release energy, grow and reproduce which is why decay takes place quicker when there is plenty of oxygen available.

Question 18

Uses of decay:

Answer 18

Decomposers are vital for recycling resources in the natural world. In sewage treatment plants, micro organisms are used to break down the bodily waste we produce. In compost heaps, decomposing micro organisms break down grass cuttings and vegetable peelings which leaves a substance that can be used as a fertiliser.

Question 19

What is the carbon cycle?

Answer 19

The carbon cycle is the constant cycling of carbon in nature.

Question 20

What are the main molecules in our body based on?

Answer 20

These molecules are based on carbon atoms combined with other elements.

Question 21

Photosynthesis and carbon:

Answer 21

Photosynthesis is one of the main ways which leads to carbon dioxide being taken out of the environment. Plants use carbon dioxide and sunlight to make carbohydrates, fats and proteins. The carbon then gets passed on to the animal that eats the plant.

Question 22

Respiration and carbon:

Answer 22

Respiration is one of the main ways which leads to carbon dioxide being returned back into the environment. The carbon released is then taken back by growing plants in the form of carbon dioxide for photosynthesis.

Question 23

Combustion and carbon:

Answer 23

Fossil fuels contain carbon which was locked away by photosynthesising organisms millions of years ago. When fossil fuels are burned, the carbon is released back into the atmosphere.

Question 24

Compost heap features:

Answer 24

Compost heaps should have holes so that micro organisms can respire and have access to oxygen. Moreover, warm and moist conditions should be provided to maximise the speed of decay. Mixing the compost heap also helps air get in.

Question 25

Carbon Cycle Diagram:

Answer 25