ecosystems

Question 1

What is an apex consumer?

Answer 1

A carnivore/omnivore, not eaten by anything else.

Question 2

What percentage of energy available is transferred from a lower level of the food chain to the one above?

Answer 2

10%

Question 3

Define interdependence.

Answer 3

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

Question 4

Name four things the plant population is affected by.

Answer 4

• rainfall
• sunlight
• minerals
• space to grow

Question 5

Name three things the animal population is affected by.

Answer 5

• food availability
• habitats
• disease

Question 6

Define an ecosystem.

Answer 6

all living (biotic) and non living (non-biotic) things in an area

Question 7

Define a community.

Answer 7

organisms within an ecosystem

Question 8

Define coexisting.

Answer 8

living together without competing for food or resources or eating each other

Question 9

Define a niche.

Answer 9

a particular role an organism has within an ecosystem

Question 10

Define bioaccumulation.

Answer 10

build up of toxic chemicals through a food chain

(It’s safer at the lower levels.)

Question 11

Define bioaccumulation.

Answer 11

build up of toxic chemicals through a food chain

(It’s safer at the lower levels.)

Question 12

Name three ways of transferring pollen.

Answer 12

• wind
• animals
• water

Question 13

Define cross pollination.

Answer 13

pollination from one plant to another

Question 14

Define self-pollination.

Answer 14

occurs between male and female parts of one flower

(This is bad for the plant.)

Question 15

Name two ways that plants ‘try’ to stop self-pollination.

Answer 15

• by one plant only having male parts or only female parts
• anthers on a plant ripen and release pollen before the stigma is ready to receive pollen

Question 16

Name three features of wind-pollinated plants.

Answer 16

• **dully-coloured **- don’t need to attract insects
• anthers loosely attached+dangle out of flowers - makes it easier for pollen to catch wind
• stigma hangs outside flower - makes it easier to catch pollen

Question 17

Name the events that happen after pollination of a flower.

Answer 17

1. pollen tube grows out of the pollen grain through the stigma, style and then down into the ovary
2. stigma makes a sugary solution - provides source of energy for pollen tube to grow
3. nucleus of pollen cell travels down the tube into ovary
4. nucleus of pollen grain joins with nucleus of ovule - fertilisation
5. zygote develops

Question 18

Name three things a seed needs to germinate and grow successfully.

Answer 18

• water - allows seed to swell up, embryo starts growing
• oxygen - used for respiration - transferring energy for germination
• warmth - speeds up reactions and germination of the plant

Question 19

Name the parts of the seed and their functions.

Answer 19

• seed coat - tough protective outer coating
• embryo - is the young root that will develop into the adult plant
• food store - store of food (starch) that a young plant uses before it can grow its own by photosynthesis

Question 20

Name the five types of seed dispersal.

Answer 20

• water
• wind
• animal internal
• animal external
• explosive