B16: Adaptations, interdependence and competition

Question 1

What is a habitat?

Answer 1

The environment in which an organism lives

Question 2

What is population?

Answer 2

The total number of organisms of the same species living in the same geographical area

Question 3

What is a community?

Answer 3

The populations of all of the different species that live in the same habitat

Question 4

What is the biotic part of an environment?

Answer 4

All the living organisms in an environment

Question 5

What is the abiotic part of the environment?

Answer 5

The non-living parts of an environment e.g. amount of water and minerals in soil

Question 6

What is an ecosystem?

Answer 6

The biotic and abiotic parts of an environment and how they interact

Question 7

Why do organisms have to compete with eachother?

Answer 7

Organisms need materials from the ecosystem, often times the materials are in short supply, leading to competition

Question 8

What do plants compete for?

Answer 8

Light
Space
Water
Minerals in soil

Question 9

What do animals compete for?

Answer 9

Food
Water
Mating partners
Territory

Question 10

What is interdependence?

Answer 10

All the species in a community that depend on each other - every animal depends on other living organisms for food. Some living organisms provide shelter.
Plants can also depend on animals e.g. bees to spread pollen or birds which can spread seeds in faeces.
If a species disappears from a community, this affects the whole community

Question 11

What is a stable community?

Answer 11

In most communities, the populations of different species remain fairly constant.
(The populations of organisms are in balance with each other and the abiotic resources e.g. water)

Question 12

What are the biotic factors that can affect a community?

Answer 12

Availability of food - all animals eat other living organisms. If availability of food falls, then the number of organisms in a community will also fall.
New predator - cause the population of prey species to fall. Also affect existing predators if they are competing for the same prey.
Competition - if a species is outcompeted, then its population can fall to the point of extinction as numbers are no longer sufficient to breed.
New pathogens - if an infectious disease emerges and spreads, it can wipe out a population of species.

Question 13

What are the abiotic factors that affect a community?

Answer 13

Light intensity - effects plants who photosynthesise, plants grow slower in dim light (if plants grow slowly, then animals that rely on them as food will also be affected).
Temperature - if temp changes, it could cause the distribution of species to change e.g. animals could migrate and plant species might disappear from the area.
Water - plants and animals need water to survive.
pH and mineral content of soil - important for plants, many cannot grow if soil is too acidic or alkaline. Plants also need certain minerals in soil.
Wind intensity and direction - affects plants e.g. strong winds blowing inland can cause plants to lose water.
Co2 - needed for photosynthesis, is less, photosynthesis also falls.
O2 - needed for aerobic respiration, level of dissolved oxygen in water can fall on hot days, which is harmful to aquatic organisms.

Question 14

What are structural adaptations?

Answer 14

Adaptations of body shape or body structure

Question 15

What are behavioural adaptations?

Answer 15

Adaptations to the animal’s lifestyle or behaviour

Question 16

What are functional adaptations?

Answer 16

Adaptations to the body functions of an organism

Question 17

How are camels adapted to the hot and dry conditions of a desert (structural adaptations)?

Answer 17

Hump on back - store of fat, thermal insulator which allows heat loss from other parts of the camel’s body, reducing water loss from sweating. Metabolic reactions can be used to produce water from the fat.
Thick coat on upper surface - insulates the top of the camel from the heat of the sun and reduces heat loss from sweating.
Leathery inside of mouth - chew plants which often have thorns (good source of water)
Long eyelashes - keep sand away from eyes
Close their nostrils to keep dust away.
Wide feet - prevent camel from sinking into sand.

Question 18

How are camels adapted to the hot and dry conditions of a desert (functional adaptations)?

Answer 18

Produce concentrated urine and dry faeces - reduce water loss.
Tolerate large changes in body temp - helps cope with the intense heat of the desert

Question 19

What are the behavioural adaptations of kangaroo rats?

Answer 19

Nocturnal - avoid heat of daytime.
During the day, they live in burrows underground, keeping them cool and protects them from predators.

Question 20

What are the adaptations of an arctic fox?

Answer 20

Structural - thick fur, insulation and reduces heat loss.
Fur on soles of feet, reducing heat loss to the ice and snow.
Small ears, reduces surface area, which reduces heat loss.
White coat, provides effective camouflage which helps the fox hunt prey.

Question 21

What are the adaptations of cacti in dry conditions?

Answer 21

Very small leaves/ no leaves at all - reduces water loss through leaves, due to the small surface area.
Spines - protect the cactus from animals.
Extensive and shallow roots - deserts are dry with minimal rain, allowing cacti to catch as much water as possible after rainfall, before the water evaporates or sinks to the ground.
Store water in stem, cacti can survive many months without rain.