Adaptations of organisms

Question 1

What is adaptation?

Answer 1

A combination of behavioural, physiological and morphological ways in which an organism meets the challenge of their environment

Question 2

What climatic ecological factors influence the distribution of organisms?

Answer 2

Temperature range 
Availability of water
Light intensity 
Light quality(what spectrums are being used) 
Day length

Question 3

What edaphic ecological factors influence the distribution of organisms?

Answer 3

pH values
Availability of nutrients
Water content
Aeration of soils

Question 4

What biotic ecological factors influence the distribution of organisms

Answer 4

Competitors

Predator and prey relationship

Question 5

what is an ecological niche?

Answer 5

An organism’s role within an ecosystem

Question 6

What is the competitive exclusion principle?

Answer 6

If organisms occupy the same ecological niche one of them will be driven to extinction

Question 7

What is fitness?

Answer 7

Those features which allow an organism to be adapted to its environment

Question 8

How is it maintained

Answer 8

Through Natural Selection : those with better fitness provide greater amounts of offspring and those with less fitness provide lesser amounts of offspring. Eventually, the less fit organisms die out and only the fittest remain (survival of the fittest)
-NS does not create useful adaptations it only increases the most suitable features

Question 9

What are the two types of selection?

Answer 9

• Stabilising

- Directional

Question 10

Discuss stabilising

Answer 10

A constant environment that benefits the status quo

Question 11

Discuss directional

Answer 11

A change in the environment means one of the extremes becomes the fittest, not the mean.

Question 12

What are xerophytic adaptations?

Answer 12

• Adaptations to reduce water loss by transpiration
• Reduced surface area: Cactus use needle leaves
• Thick cuticle
• Leaf hairs: restrict airflow over leaf surface trapping a layer of humid air
• Sunken stomata, creating low water potential gradient between the outside and inside of stomata
• Succulent tissue: large stores of water
• Deep roots: Reaches groundwater

Question 13

Name a xerophytically adapted plant

Answer 13

Marram grass

Question 14

What are hydrophytic adaptations?

Answer 14

• Adaptations for living in water
• Stomata on upper leaf surface to prevent their submergence and allow gaseous exchange to occur
• Aerenchyma: large air spaces helping leaves float