chapter 16

Question 1

habitat

Answer 1

The part of an ecosystem where an organism lives.

Question 2

species

Answer 2

This is a group of organisms that can breed together to…

to produce fertile offspring

Question 3

population

Answer 3

This is the organisms of the same species that share a particular habitat.

Question 4

community

Answer 4

This is made up of all the organisms that share a particular habitat.

Question 5

competition

Answer 5

A word that describes the fact that organisms often need the same competition.

Question 6

interdependent

Answer 6

A word that describes how organisms rely on and impact upon each
other.

Question 7

biotic factors

Answer 7

Other living things that can affect a particular population. E.g. a new pathogen or parasite.

Question 8

abiotic factors

Answer 8

Non-living things that can affect a particular population. e.g. light- intensity.

Question 9

how does the abiotic factor temperature affect its communities?

Answer 9

Can limit photosynthesis so affects growths in plants.

In cold climates, temperature is always limiting. This affects the numbers of herbivores.

Question 10

how does the abiotic factor moisture levels affect its communities?

Answer 10

If there is no water, there will be no life. As a rule, plants and animals are relatively rare in desert as the availability of water is limited.

Question 11

how does the abiotic factor soil pH and mineral content affect its communities?

Answer 11

The level of mineral ions, for example, nitrate ions, has a considerable impact on the distribution of plants. Carnivorous plants such as sundews thrive where nitrate levels are very low because they can trap and digest animal prey.

Question 12

how does the abiotic factor wind intensity

affect its communities?

Answer 12

In areas with strong prevailing winds, the shape of the trees and the whole landscape is affected by the wind.

Question 13

how does the abiotic factor direction affect its communities?

Answer 13

It also means that plants transpire fast.

Question 14

how does the abiotic factor availability of oxygen affect its communities?

Answer 14

The availability of oxygen has a huge impact on water-living organisms. Some invertebrates can survive in water.

Question 15

how does the biotic factor availability of food affect its communities?

Answer 15

When there is plenty of food, organisms breed successfully. When food is in short supply, animals struggle to survive and often do not breed.

Question 16

how does the biotic factor new pathogens or parasites affect its communities?

Answer 16

When a new pathogen or a parasite emerges, organisms have no resistance to the disease. A new pathogen can damage and even wipe out populations in a community.

Question 17

how does the biotic factor new predators arriving affect its communities?

Answer 17

Organisms that have no defences against new predators may quickly be wiped out.

Question 18

how does the abiotic factor light intensity affect its communities?

Answer 18

Can limit photosynthesis so affects distribution of plants and animals
􏰀Breeding cycles of many animals and plants is linked to day length and light intensity

Question 19

What are carnivores in competition for?

Answer 19

They compete for prey. Small mammals such as mice ar eaten by animals such as foxes,
owls, hawks and domestic cats. The animal best adapted to finding and catching mice will be
most successful. Carnivores have to compete with their own species for their prey as well as
with different species.

Question 20

What do prey organisms compete for?

Answer 20

They compete for their life and not to get caught. these animals compete for very similar food types due to their small sizes meaning they eat similar foods.

Question 21

Why are animals that eat a wide range of food more likely to be successful?

Answer 21

If they have a wide range of food this means that is easier for them to find food that they can eat therefore keeping them alive and healthy.

Question 22

Why was the introduction of rabbits to Australia bad for the ‘native’ ecosystem?

Answer 22

It led to the extinction of a number of common species that simply could not compere with the grass eating and breeding abilities of the rabbits.

Question 23

Give two reasons why an animal needs to set-up and defend a territory.

Answer 23

Most animals cannot reproduce successfully if they have no territory so they will compete for the best spaces. Also when animals reproduce they need somewhere to look after their offspring and care for them in that they have to provide food for them.

Question 24

Give two ways in which males compete for females

Answer 24

The males fight between themselves. The winner gets to mate with several females. The male animals also put a lot of effort into impressing females.

Question 25

Give three examples of how plants avoid competition with each other (hint – growth season, root length, light…)

Answer 25

Small plants found in woodlands often grow and flower very early in the year. This is when plenty of light gets through the bare branches of the trees.

Plants have different types of roots. Some plants have shallow roots taking water and nutrients from near the surface of the soil, while other plants have long, deep roots that go far underground.

If one plant is growing in the shade of another, it may grow taller to reach the light. It may also grow leaves with a larger surface area to take advantage of the light it does get. Some plants have adaptations such as tendrils or suckers that allow them to climb up artificial structures or large trees to reach the light.

Question 26

Give two ways that plants spread or ‘disperse’ their seeds in order to reduce competition between the parent plant and it’s seedlings.

Answer 26

To reproduce successfully, a plant has to avoid competition with its own seedlings for light, space, water and mineral ions. Many plants use the wind to help them spread their seeds as far as possible. They produce fruits or seeds with special adaptations for flight to carry their seeds away. Plants also use explosive seed pods, animals, or even water to carry their seeds as far away as possible.

Question 27

What is a structural adaptation?

Answer 27

Features related to physical structure - shape, colour and size.

Question 28

What is a behavioural adaptation?

Answer 28

Features related to short or long-term behaviours - migration, basking, tool use

Question 29

What is a physiological/ functional adaptation?

Answer 29

Features related to processes - usually intentional, cellular processes.

Question 30

two example of Structural adaptations in plants

Answer 30

An example of this is the formation fo spines, which are found on many species, such as cacti and roses, and can stop a plant being eaten by grazing animals. Other examples of structural adaptations include plants with wide-ranging, shallow roots to absorb lots of water after rain, large leaves to maximise photosynthesis and flowers, which attract insects to pollinate them.

Question 31

two examples of behavioural adaptations in plants

Answer 31

All plant shoots grow quickly towards the light to maximise photosynthesis. Growth towards the light and other tropisms ensure that plants can respond to changes in their environment. Plant roots which grow downwards may be because of gravity or growing directly towards water to maximise photosynthesis. Other plants like the Venus flytrap have evolved structural and behavioural adaptations to catch insects. The flytrap itself is a structural adaptation and the closing of the trap to catch an insect is a behavioural adaptation.

Question 32

two examples of Physiological/Functional adaptations in plants

Answer 32

An example of this is the formation of poisons for defence. The nettle plant stings us when we brush the tiny needles on its leaves, which contain poison. Other plants, like deadly nightshade, are so poisonous they can kill if consumed by humans.

Question 33

Give 2 examples of Structural adaptations Animals

Answer 33

Animals have a wide range of structural adaptations including sharp claws to catch prey, dig burrows or scratch trees to signal territories. Predators and prey often have similar adaptations. Both are likely to have good vision and hearing. Prey often has eyes on the sides of their heads to easily spot predators. Predators often have their eyes on the front of their heads to judge distance to their prey.

Question 34

give 2 examples of behavioural adaptations in animals

Answer 34

The scratching of trees is a behavioural adaptation. Behavioural adaptations include mating rituals, like a male peacock bird showing his tail feathers to attract a female mate. They can also include working together in packs like wolves to hunt prey. Other animals have evolved the behavioural adaptation of using tools. For example, crocodiles use twigs to lure birds, who would pick them up to build nests.

Question 35

give 2 examples of Physiological/Functional adaptations in animals

Answer 35

The production of venom is an example of this. Many predators such as snakes and spiders produce venom both to defend themselves and kill their prey.

Question 36

Define the term extremophile in detail

Answer 36

Organism that survive and reproduce in the most difficult conditions are known as extremophiles. Many extremophiles are microorganism, especially archaea. Micro-organisms have a range of adaptations that mean they can live in many different environments. Some extremophiles can live at very high temperatures. Bacteria known as thermophiles can survive at temperatures of over 45 degrees celsius and often up to 80 degrees celsius of higher. These extremophiles have specially adapted enzymes that do not denature at these high temperatures. Many thermophiles cannot survive and reproduce at low temperatures. Other bacteria and archaea live at very low temperatures, down to -15 degrees celsius. They are found in ice packs and glaciers around the world. In short an extremophile is an ogranisms that can live where nothing else can and thrive when the going gets tough.

Question 37

Give two examples of

adaptations found in different extremophiles

Answer 37

They have specially adapted enzymes that don’t denature at very high temperatures. This is known as being resistant to warm temperatures. enzymes that function in very high temperatures, enzymes that function at very low temperatures, they have the ability to get rid of excess salt and they have the ability to respire without oxygen.