B16 - Adaptation, Interdependence and Competition

Define 'community'.

A group of interdependent organisms that are made of different species

Define 'ecosystem'.

The interaction of a community with the abiotic parts of the environment

What are abiotic factors? State two examples.

Non-living factors in an environment (e.g. light intensity, soil pH, wind, humidity, temperature)

What are biotic factors? State two examples.

Living factors in an environment (e.g. predators, competitors, pathogens/microorganisms)

Define 'population'.

A group of organisms of one species that interbreed and live in the same place at the same time

What is interdependence?

A relationship that describes how all species within a community depend on each other to survive

What is meant by a stable community?

Where all the species and environmental factors are in balance, hence population sizes remain fairly constant

A disease causes large areas of trees to die. Is their death cause by an abiotic or biotic factor?

Biotic (as diseases are caused by pathogens, which are living beings)

Briefly explain why low light intensity may decrease animal populations.

Less light → less photosynthesis by plants → poor plant growth → less plant available for animals to eat → less herbivores grow and survive → further affects higher levels in the food chain

Sort the following into abiotic and biotic factors: soil pH, availability of food, oxygen availability, wind intensity, new competitors, carbon dioxide levels.

Abiotic: soil pH, CO₂ levels, O₂ availability, wind intensity

State three biotic factors.

New pathogens, new predators, new competitors, food availability

State an equipment that is commonly used to investigate a population of plants in a particular area.

Quadrat

What is quantitative sampling?

A technique to record and estimate the number of organisms in a particular area

How can the distribution of a species be measured?

Sampling along a transect

State a difference between quantitative sampling and transect sampling.

Quantitative sampling takes samples at random coordinates

What are the three things that animals compete for?

Food, mates, territory

Give one characteristic of a lion that makes it a good competitor.

Sharp teeth/claws

Give one characteristic of a deer that makes it a good competitor.

Horns/Antlers

Give one characteristic that a peacock has that makes it a good competitor, and state what it is competing for using this trait.

Behaviour (e.g. mating dance) / Attractive, colourful feathers to attract mate

Tigers urinating on trees is a behaviour adaptation to compete for…?

Territory

Wasps building nests is a behaviour adaptation to compete for…?

Shelter/Habitat

Owls' sharp hearing is an adaptation to compete for…?

Food

What are the four things that plants compete for?

Light, space, water, mineral ions

Some small plants in woodlands grow only in winter and die before spring comes. Suggest why this occurs.

To avoid competition for sunlight when large trees grow leaves and block out sunlight in spring/summer

Suggest why plants may have different root depths.

To avoid competition for water and/or mineral ions at the same soil depth

Suggest why seed dispersal is considered an adaptation to avoid competition.

Seed is carried far away instead of landing right next to parent plant, so offspring plant doesn't compete with parent plant

'Cactus' long roots is a feature to help compete for…?

Water

Large flowers are a feature to help compete for…?

(Attract) Pollinators

Weeds' rapid growth in height is a feature to help compete for…?

Light

What are extremophiles?

(Micro)organisms that live in environments that are very extreme (e.g. high temperature, pressure, salt concentration)

Which domain tends to include most extremophiles?

Archaea

State the specific name given to extremophiles that are adapted to live in high temperatures.

Thermophiles

Suggest one adaptation that thermophiles have to help them live in high temperatures.

Special enzymes with higher optimal temperature (don't denature at high temperature) / Specially structured cell membrane and/or cell wall

Suggest one adaptation that halophiles have to help them survive in salty areas.

Special cytoplasm to prevent water loss by osmosis / Special cell membrane/cell wall

For animals that live in cold climates, would they have adaptations to increase or decrease their surface area to volume ratio?

Decrease

Why do animals that live in hot climates adapt to have a high SA:V ratio?

Increase heat loss

State an adaptation that polar bears have to survive in cold climates.

More insulation (thick fat layer + fur)

Give a behavioural adaptation of penguins.

Huddling

What is stored in camels' humps and what is it for?

Fat store → can be metabolised to make water

Apart from their humps, give one other adaptation of camels to help them reduce water loss.

Specially adapted kidneys / Very little sweating

Arctic foxes' fur coat changes from grey to white during winter. Suggest two reasons why.

Reduce heat loss by radiation + Better camouflage in the snow

What is the major way in which plants lose water in hot, dry conditions?

Transpiration

Why do plants in dry and hot conditions have curled leaves?

Traps moist air → reduce water vapour concentration gradient → reduce transpiration

Why do some plants have thorns?

Prevent predation by herbivores

Why do some plants have long roots?

Increase water uptake

Why do cacti have swollen stems?

Store water

Why do cacti have spine-like leaves?

Reduce SA → reduce water loss