Living Things and their Environment

Question 1

Define the main key terms; ecology, habitat, population, community, ecosystem. (5)

Answer 1

Ecology - The relationship of living things to their environment and to each other/the study of it.

Habitat​ - A part of the environment that can provide food, shelter, and a breeding site.

Population​ - All the members of the same species living in one area.

Community​ - A community is two or more populations of organisms.

Ecosystem​ - a biological community of interacting organisms and their physical environment.

Question 2

What are the factors that affect an environment? (2) Give examples of Abiotic and Biotic factors. (4)

Answer 2

An organism’s surroundings (abiotic and biotic factors) can influence its distribution.

Abiotic:
Wind speed

Wind speed is measured with an anemometer. It affects the rate of water loss by plants and therefore affects their survival rates in exposed areas.

pH levels

pH levels are measured using a pH probe. It affects the survival and therefore distribution of plants. Most plants prefer neutral conditions but some will only grow in acidic or alkaline conditions.

Biotic:
The number of predators

The number of predators can determine how many animals there are in an ecosystem.

The types of plants

The types of plants can determine which animals live in that ecosystem.

Question 3

Give an example of an organism and how it has adapted to its environment. (3)

Answer 3

Living things are adapted to their habitats. This means that they have special features that help them to survive.

An African elephant, for example, lives in a hot habitat and has very large ears that it flaps to keep cool.

Question 4

What causes changes in populations sizes? (1)

Answer 4

Immigration and Emigration.

Question 5

What are the four factors limiting population growth? (2)

Answer 5

Disease, Competition, Food, Predators.

Question 6

Name the organisms at all trophic levels. (7)

Answer 6

Producers: Green plants - they make glucose during photosynthesis.
Primary consumers: Usually eat plant material - they are herbivores. For example rabbits, caterpillars, cows and sheep.
Secondary consumers: Usually eat animal material - they are carnivores. For example cats, dogs and lions.
Predators: Kill for food. They are either secondary or tertiary consumers.
Prey: The animals that predators feed on.
Scavengers: Feed on dead animals. For example, crows, vultures and hyenas are scavengers.
Decomposers: Feed on dead and decaying organisms, and on the undigested parts of plant and animal matter in faeces.

(Use the acronym 4P2SD)

Question 7

What is the role of decomposers in a food chain? (4)

Answer 7

Decomposers are bacteria and fungi, which break down dead organisms in a process called decomposition or rotting. They do this by releasing enzymes onto the dead matter and afterwards, consume the broken down substances. They form a vital role in the recycling of matter. When organisms die and decompose plants absorb the broken down nutrients through their roots.

Question 8

All energy in a food chain comes from what? (1)

Answer 8

The Sun

Question 9

What % of energy is passed on to each level of the food chain? (1)

Answer 9

10%

Question 10

Green plants get their energy from what? (1)

Answer 10

Photosynthesis

Question 11

Animals get their energy from what? (1)

Answer 11

Respiration