ecology pt2

Question 1

what do all food chains begin with

Answer 1

producers

Question 2

what do producers do

Answer 2

they synthesize new molecules

The producer is usually a green plant, which makes glucose molecules by photosynthesis.

Question 3

what are consumers that eat other animals called

Answer 3

consumers that eat other animals are predators and those eaten are prey. top consumers are apex predators. they are carnivores with no preditors

Question 4

what happens in a stable community

Answer 4

in a stable community, the numbers of predators and preys rise and fall in cycles.

Question 5

define biodiversity

Answer 5

the variety of all the different species of organisms on earth.

Question 6

what does a high biodiversity mean

Answer 6

a high biodiversity helps ecosystems to be stable because species depend on each other for food and shelter

Question 7

what factors put biodiversity at risk

Answer 7

availability of water

temperature

atmospheric gases

these changes may be due to

changes in the seasons

geographic activity

human interaction

pollution

kills plants and animals which can reduce biodiversity

Question 8

what is the effect of human population increasing

Answer 8

this means that more resources are used and more waste is produced

unless waste and chemical materials are properly handled more pollution will be caused

Question 9

In what areas can pollution occur

Answer 9

pollution can occur water from sewage, fertilizers or toxic chemicals

in air, from gases e.g. sulfur dioxide which dissolves in moisture in the atmosphere to produce acid rain

on land, from landfill and toxic chemicals e.g. pesticides and herbicides, which may be washed from land into water

Question 10

how do humans overexploit the environment

Answer 10

building, quarrying, farming, and dumping waste can all reduce the amount of land available for other animals and plants

producing garden compost destroys peat bogs reducing the area of this habitat and the variety of different organisms that live there

the decay or burning of the peat releases carbon dioxide into the atmosphere

Question 11

what has deforestation accrued to in tropical rain forests

Answer 11

provide land for cattle and rice fields to provide more food

grow crops from which biofuels can be produced

Question 12

define global warming

Answer 12

global warming is a gradual increase in the temperature of the earth. many scientists think that it is being caused by changes in various gases, caused by pollution and deforestation

Question 13

what are the biological consequences for Global warming

Answer 13

loss of habitat, when low lying areas are flooded by rising sea levels

changes in the distribution of species in areas where temperature or rainfall has changed

changes to the migration patterns of animals

Question 14

how have scientists conserved biodiversity

Answer 14

setting up breeding programs for endangered species

protecting rare habitats

encouraging farmers to keep margins and hedgerows in fields

reducing deforestation and carbon dioxide emissions

recycling rather than dumping waste in landfill

Question 15

How does decomposition help the environment?

Answer 15

when decomposers break down dead material by secreting enzymes, small soluble food molecules then diffuse into the microorganisms

this also releases nutrients into the environment, which the producers need in order to grow

Question 16

What happens in the water cycle?

Answer 16

1) Energy from the sun makes water evaporate from the land and sea, turning it into water vapour. Water also evaporates from plants (transpiration)
2) The warm water vapour is carried upwards. When it gets higher up it cools and condenses to form clouds
3) Waterfalls from the clouds, as precipitation, onto land where it provides fresh water for plants and animals
4) it then drains into the sea, before the whole process starts again

Question 17

What is the percentage of CO2 in the air?

Answer 17

0.04%

Question 18

How does carbon move up the food chain?

Answer 18

When the plants and algae are eaten by animals, some carbon becomes part of the fat and proteins in their bodies so carbon moves up the food chain

Question 19

What is photosynthesis used for?

Answer 19

to make glucose, which can be turned into carbohydrates, fats and proteins that make up the bodies of plants and algae

Question 20

What happens in the carbon cycle?

Answer 20

1) CO2 is removed from the atmosphere by green plants and algae during photosynthesis
2) When plants and algae respire, some CO2 is returned
3) When the plants and algae are eaten by animals, some carbon becomes part of the fat and proteins in their bodies so carbon moves up the food chain
4) when the animal respire some CO2 is returned to the atmosphere
5) when plants, algae and animals die, decomposers feed on their remains and CO2 is returned to the atmosphere when they respire
6) the combustion of wood and fossil fuels also releases CO2