Biology Ecosystems

Question 1

Define food chain.

Answer 1

A food chain is a diagram that shows what an organism eats.
It shows the transfer of energy between organisms.
Part of a food web, starting with producer and ending with a top predator.

Question 2

What is a producer?

Answer 2

A green plant or algae that makes its own food using sunlight by the process of photosynthesis.

Question 3

What is the second organism in a food chain?

Answer 3

A herbivore.

Question 4

What is the third organism in a food chain?

Answer 4

A carnivore.

Question 5

What is a consumer?

Answer 5

An animal that eats plants or other animals.

Question 6

What do the arrows show in a food web?

Answer 6

The transfer of energy (stored in food) from one organism to the next.

Question 7

Define prey and predator.

Answer 7

An animal that is eaten by another animal.
An animal that eats other animals.

Question 8

How many links are there in a food chain?

Answer 8

Most food chains have only 4 or 5 links.

If there were more, too little energy would be transferred to organisms at the top of the food chain.

Question 9

At each level of the food chain, ……. energy is transferred to the organism in the level above.

Answer 9

Less

Question 10

How is energy lost in a food chain?

Answer 10

Some energy is transferred to the surroundings by heating and as waste products.

Question 11

How much energy available at one level, is transferred to the next level?

Answer 11

About 10%

Question 12

Define food web.

Answer 12

A diagram that shows how food chains in an ecosystem are linked.

Question 13

Define decomposers.

Answer 13

Organisms, bacteria and fungi that break down dead plant and animal material. This releases nutrients into the soil or water.

Question 14

Define bioaccumulation.

Answer 14

The build up of toxic chemicals inside organisms in a food chain.

Question 15

Define population.

Answer 15

A group of the same species living in an area.

Question 16

Define habitat.

Answer 16

The area in which an organism lives.

Question 17

What is interdependence?

Answer 17

The way in which living organisms depend on each other to survive, grow and reproduce.

Question 18

Why is the decreasing bee population a concern?

Answer 18

If bee populations decrease, then less pollination occurs, which means fewer crop plants may be produced, which means human food supplies could decrease.

Question 19

What is the size of a population affected by?

Answer 19

The number of predators and prey
Diseases
Pollution
Competition

Question 20

What would happen if the grass went for long periods without rain?

Answer 20

The grass would die, and there would be less food for insects and animals such as snails, caterpillars and rabbits. These organisms would die, unless they moved to another area. All other animals in the food web would also die as their food source has gone.

Question 21

Give an example of a chemical that can be passed along a food chain?

Answer 21

Insecticides.
There are the chemicals that some farmers use to kill insects that eat their crops.

Question 22

Describe how bioaccumulation works with insecticides?

Answer 22

Farmers use them on their crops.
Some are washed into rivers and end up in the sea.
Fish absorb small amouns of these chemicals and store them in their body.
Seals eat the fish and the insecticides passes into their body.
Levels of the chemical accumulate in the seals, as they eat a lor of fish.
Polar bears eat seals and so it accumulates to high levels in the polar bear and can make them ill and cuase death.

Question 23

Define ecosystem.

Answer 23

The name given to the plants and animals that are found in a particular location and the area in which they live. These plants and animals dependon each other to survive.

Question 24

The organisms in an ecosystem are known as a ….

Answer 24

community

Question 25

The conditions found in a habitat are known as the…

en

Answer 25

environment.

Question 26

In an ecosystem, what is a niche?

Answer 26

Each of the organisms living in an ecosystem has its own niche.
A niche is a particular place or role that an organism has within an ecosystem.

Question 27

In a habitat, what is competition?

Answer 27

In a habitat with a limited supply of resources, such as food, water and space.
To survive, animals compete with each other to get enough of these resources. This is known as competition.

Question 28

List four things animals/living organisms compete for?

Answer 28

1. Food
2. Water
3. Space - to hunt and for shelter
4. Mates - to reproduce

Question 29

State why flowers have petals.

Answer 29

The petals are normally brightly coloured to attract insect so that they will be pollinated.

Question 30

State where the pollen is made.

Answer 30

The pollen is made in the anther.

Question 31

State three ways in which pollen can be transferred between plants.

Answer 31

Wind
Insects
Animals

Question 32

Explain how plants are pollinated by insects.

Answer 32

Brightly coloured and sweet-smelling petals to attract insects.
Nectar - a sweet, sugarly fluid; bees use nectar to make honey.
Smaller quantities of pollen produced.
Pollen is often sticky or spiky to stick to insects
Anthers and stigma are held firmly inside the flower to insects can brush against them.
Stigma has a sticky coating, so pollen sticks to it.

Question 33

Explain how plants are pollinated by wind.

Answer 33

Small petals, often brown or dull green.
No nectar.
Pollen prduced in large quantities to increase the chances of it reaching another plant.
Pollen has a very low mass - it is very light and can be blown away easily by the wind.
Anthers are losely attached and dangle out of the flower to make it easier to release pollen into the wind.
Stigma hangs outside the flower to make it easier to catch pollen blown by the wind.

Question 34

Define stigma.

Answer 34

The female part of the flower that is sticky to catch grains of pollen.

Question 35

Define stamen.

Answer 35

The male reproductive part of a flower made of two parts:
Anther
Filament

Question 36

Define anther.

Answer 36

Produces pollen, the male sex cells.

Question 37

Define filament.

Answer 37

Holds up the anther.

Question 38

Define carpel.

Answer 38

The female reproductive part of a flower.
Stigma
Style
Ovary

Question 39

Define style.

Answer 39

Holds up the stigma in a flower.

Question 40

Define ovary in a flower.

Answer 40

Contains ovules, the female sex cells.

Question 41

Define pollination.

Answer 41

The transfer of pollen from the male part of the flower to the female part of the flower on the same (or another) plant.

Question 42

Define pollen.

Answer 42

Contains the plant male sex cells found on the stamens.

Question 43

Describe the structure of a flower.

Answer 43