B7 Ecology random revision (pages 83-94)

Question 1

What is a community?

Answer 1

All the populations of different species living in the same habitat.

Question 2

What term is used to describe the place where an organism lives?

Answer 2

Habitat

Question 3

Name two things that plants compete for in an ecosystem, other than light?

Answer 3

Any two from e.g.

Mineral ions
Space
Water

Question 4

If one species is removed it can affect a whole community. What word can be used to describe this?

Answer 4

Interdependence

Question 5

Give two examples of abiotic factors that can affect the animal species in a community?

Answer 5

Any two from e.g.

Moisture level
Light intensity
Temperature
Wind intensity and direction
Oxygen level (for animals that live in water).

Question 6

In an ecosystem the pH of the soil changes. Explain how this could lead to a decrease in the population of animals only eat plants?

Answer 6

E.g. It could negatively affect plant growth. This would reduce the availability of food for plant-eating species, which would lead to a decrease in their numbers.

Question 7

Give two examples of biotic factors that can affect plants?

Answer 7

Any two from e.g.:

Competition
Nutrient/food availability.
New pathogens

Question 8

What kind of adaptations are features of an animal’s body, such as its shape or colour?

Answer 8

Structural adaptations

Question 9

Some birds migrate to warmer places for the winter. What type of adaptation is this an example of?

Answer 9

Behavioural

Question 10

Some desert animals conserve water by producing very little sweat. What type of adaptation is this an example of?

Answer 10

Functional

Question 11

Give two examples of the type of extreme conditions that extremophiles might live in?

Answer 11

Any two from e.g.
High temperaturHigh salt concentration
High pressure

Question 12

What comes after a producer in a food chain?

Answer 12

A primary consumer

Question 13

What term is used for the organism in a food chain that makes its own food using photosynthesis?

Answer 13

Producer

Question 14

Which organism in the food chain is the secondary consumer?

Grass&raquo_space;>rabbitt»>stoat»>golden eagle

Answer 14

Stoat

Question 15

In a stable community, if the population of a predator falls, what will happen to the population of its prey?

Answer 15

It will increase

Question 16

What is meant by the ‘distribution’ of a species?

Answer 16

Where a species is found

Question 17

A student used quadrats to sample an area for red clover plants. She recorded her results. Describe how you would calculate the mean number of red clover plants per quadrat?

Quadrat 1 2 3 4 5 6
___________________________________________
Number of 8 12 14 8 10 7
red clovers

Answer 17

First, find the total number of red clover plants counded, then divide this by the number of quadrats used.

Question 18

A student used quadrats, each with an area of 0.5m², to sample a field. Then he calculated the mean number of buttercups per quadrat. How could he use this to estimate the population size of buttercups in the field?

Answer 18

First work out the mean number of buttercups per m². Then multiply this by the total area of the field (in m²)

Question 19

Describe two ways that you can collect data along a transect?

Answer 19

Count all the organisms your’e interested in that touch the transect.

Place quadrats along the transect (either next to each other or at regular intervals) and cound all the organisms you’re interested in that are inside each quadrat.

Question 20

When sampling using a quadrat, sometimes the percentage cover of organisms is estimated rather than counting individuals. Explain why?

Answer 20

It can be difficult to count numbers of some organisms in a quadrat (e.g. plants like grass).

Question 21

Describe how a student could use a quadrat to estimate the percentage cover of an organism within the quadrat?

Answer 21

Count the number of squares withing the quadrat that are more than half covered by the organism. Divide this by the total number of squares in the quadrat and multiply the result by 100.

Question 22

What is the name of the process through which water vapour forms clouds?

Answer 22

Condensation

Question 23

During the water cycle, what causes water from the land and sea to turn into water vapour in the air?

Answer 23

Energy from the sun makes the water evaporate.

Question 24

Plants need mineral ions to grow. How are mineral ions returned to the soil from dead or waste material?

Answer 24

The material is broken down by microorganisms (decay).

Question 25

Give two processes in the carbon cycle which release carbon dioxide back into the air?

Answer 25

Any two from:

Burning fossil fuels or plant/animal products
Plant respiration
Animal respiration
Respiration of microorganisms during decay.

Question 26

Explain how carbon from the atmosphere ends up in carbon compounds in animals?

Answer 26

Plants and algae take in carbon dioxide from the atmosphere during photosynthesis. they use the carbon in caron dioxide to make glcose, which they can turn into carbohydrates, fats and proteins. When the plants and algae are eaten by animals, some carbon from these compounds becomes part of the fats and proteins in their bodies.

Question 27

How are carbon compounds from animal waste materials converted back to carbon dioxide in the air?

Answer 27

Microorganisms (and detritus feeders) break down the waste. When these organisms respire, carbon dioxide is returned to the air.

Question 28

What term describes the variety of different species of organisms withing an ecosystem?

Answer 28

Biodiversity

Question 29

Give one example of how pollution occurs on land?

Answer 29

any one from e.g.:

Toxic chemicals (e.g. pesticides and herbicides) are used for farming

Nuclear waste is buried underground

Household waste is dumped in landfill sites.

Question 30

Explain how increasing levels of greenhouse gases in the Earth’s atmosphere are causing blobal warming?

Answer 30

The Earth absorbs energy from the Sun and then radiates some of it back out. This energy is absorbed by greenhouse gases in the atmosphere and re-radiated out in all directions, including back towards the Earth. More greenhouse gases in the atmosphere means that more energy is absorbed and radiated out, so the Earth becomes warmer.

Question 31

Name two greenhouse gases whose levels in the Earth’s atmosphere are currently increasing?

Answer 31

Carbon Dioxide and Methane

Question 32

Explain how global warming could lead to a change in the distribution of species?

Answer 32

E.g. If the Earth becomes warmer, species that do well in warm conditions may spread further, and species that need cooler temperatures may become less widespread.

Question 33

Describe one way that global warming could lead to flooding of habitats?

Answer 33

E.g. higher temperatures cause seawater to expand and ice to melt, resulting in rising sea levels. This could flood habitate in low-lying places

Question 34

How can a demand for biofuels lead to deforestation in tropical areas?

Answer 34

Some biofuels, like ethanol, are made from crops. Forests are cut down to clear land to grow crops for these fuels.

Question 35

State two environmental problems resulting from deforestation?

Answer 35

Any two from e.g.:

Less carbon dioxide is removed from the atmosphere by photosynthesis.

Carbon dioxide is released when trees are burnt to clear land.

Microorganisms feeding on dead wood release carbon dioxide through respiration

The destruction of the habitat risks many species becoming extinct reducing biodiversity.

Question 36

State two environmental problems with destroying peat bogs?

Answer 36

Any two from e.g.:

Burning of peat as a fuel releases carbon dioxide into the atmosphere.

Draining peat bogs brings the peat into contact with the aire more, so it decomposes more. Carbon dioxide is released as it decomposes.

It reduces the area of the habitat and the number or organisms that live there, reducing biodiversity.

Question 37

State two ways in which humans reduce the amoung of land available for other animals?

Answer 37

Any two from e.g:

Building
Quarrying
Farming
Dumping Waste

Question 38

Explain how introducing field margins for hedgerows around fields where only one crop is grown can help to increase biodiversity?

Answer 38

They can provide a habitat for a wider variety of organisms that could survive in the single crop habitat provided by the field.

Question 39

Explain how schemes to protect rare habitats help to maintain biodiversity?

Answer 39

E.g. they help to protect the species that live there, which preserves the ecosystem and maintains biodiversity in the area.