Unit 2 - AOS1 - Adaptations & Population Dynamics

Question 1

Limiting factors

Answer 1

environmental conditions that restrict the types of organisms that can survive in a given environment

Question 2

Examples of limiting factors

Answer 2

• light intensity
• water availability
• temperature
• dissolved oxygen levels

Question 3

Structural adaptations

Answer 3

physical features that enable organisms to survive in their enviro
e.g. blubber in seals

Question 4

Behavioural adaptations

Answer 4

Activities that an organisms performs in response to internal or external stimuli
e.g. birds migrate to warmer regions in winter

Question 5

Physiological adaptations

Answer 5

Internal and /or cellular features (processes) of an organism
e.g. vasoconstriction

Question 6

Ecology

Answer 6

Study of how life interacts within one’s environment

Question 7

What do limiting factors prevent ?

Answer 7

overpopulation of a species

Question 8

3 points about populations

Answer 8

1. communities of animals, plants, or humans among whose members interbreeding occurs.
2. dynamic
3. size will depend on and fluctuate with availability of resources.

Question 9

3 population stages

Answer 9

1. Slow growth : population is slow to adapt to particular environment
2. exponential growth : high birth rates due to natural selection and resources
3. carrying capacity (plateau) : greatest number of individuals that the environment can sustain.

Question 10

‘K’ selected species

Answer 10

Sigmoid phenomena
(there is a plateau at carrying capacity)

Question 11

‘R’ selected species

Answer 11

Peak phenomena
(“Boom and Bust”, fluctuates)

Question 12

Population Size

Answer 12

“Measure the number of individuals in a population at a given time”
Growth Rate = Birth rate = (immigration rate) - (death rate + emigration rate)

Question 13

Population Density

Answer 13

“The number of individuals of a population a certain at a given time”
-Terrestrial: The number of individuals per unit of area.
-Aquatic: the number of individuals per unit of volume.

Question 14

Population Distribution

Answer 14

“The spatial pattern in which the members of population are found in their habitat”

• can help keep track of populations

Question 15

Population Age distribution

Answer 15

“The proportion of individuals in each age group in a population”
Pre-reproductive, reproductive, post-reproductive

Question 16

population momentum (in terms of age distribution)

Answer 16

When a population has a large % of individuals in pre-reproductive category has high potential for growth = population momentum.

Question 17

Types of distribution

Answer 17

Random - irregularly spaced (e.g. dandelions)
Uniform - rare, evenly spaced (e.g. penguins)
Clumped - rare, grouped together (e.g. Hurd of elephants)

Question 18

2 Factor impacting populations

Answer 18

Density Dependent:
“Factors where the severity is impacted by the density of a population”
(e.g. reproduction, migration, deaths, diseases)

Density Independent:
“Factors where the severity is NOT impacted by the density of a population”
(e.g. natural disasters, bushfires, human destruction)