Ecology (General Principles)

Question 1

Food Web

Answer 1

Many food chains in relation to each other

Question 2

Trophic Pyramid

Answer 2

Show comparative biological productivity for each level of the food chain - As one gets further up the food chain, the energy gained from that level decreases to about 10% of the previous level

Question 3

Climax

Answer 3

Stable / mature population or community

Question 4

Succession

Answer 4

Replacement of one community by another - developing toward a climax

Question 5

Primary succession

Answer 5

Succession of vegetation that starts from barren land / water to a climax community

Question 6

Secondary succession

Answer 6

Succession of biotic communities in areas where natural vegetation + existing community has been removed but soil remains

Question 7

Tertiary Succession

Answer 7

Process of recolonizing in areas that has been completely abandoned by plants + animals due to complete destruction by natural phenomenon - occurs very rarely

Question 8

Extinction

Answer 8

No remaining living organisms; gone forever

Question 9

Selection

Answer 9

How likely a population can survive - rely on reproductively + adaptive traits / inherited characteristics

Question 10

Natural selection (NS)

Answer 10

The differential survival and reproduction of organisms with genetic characteristics that enable them to better utilize environmental resources

Question 11

Stabilizing selection

Answer 11

Type of natural selection where genetic diversity decreases as population stabilizes on a particular trait

Question 12

Disruptive selection

Answer 12

Type of natural selection that simultaneously favors individuals at both extremes of the distribution - They produce more offsprings than those in the center (produce 2 peaks in the distribution of a particular trait)

Question 13

Directional selection

Answer 13

Occurs in population genetics when NS favors a single allele and therefore allele frequency continuously shift in one direction.

Question 14

Artificial selection

Answer 14

Process where breeders choose the variants to be used to produce succeeding generations

Question 15

Limiting Factor

Answer 15

Factor that limits a population’s growth (ex: resources, shelter, food, disease)

Question 16

Biodiversity

Answer 16

Number and variety of organisms within one region (biome)

Question 17

Carrying Capacity

Answer 17

Maximum number of individuals of a species or population a given environment can sustain

Question 18

Age of Reproduction

Answer 18

Average age in an organism when it becomes capable of reproduction

Question 19

R-selected organisms

Answer 19

Put most of their energy into rapid growth and reproduction - common for organisms occupying unpredictable environments (ex. weeds)

Question 20

K-selected organisms

Answer 20

Put most of their energy into growth - common in stable environments near carrying capacity (ex. redwood trees)

Question 21

Geographic Range

Answer 21

Where the members of a species’ populations live, feed, and reproduce - can change due to establishment / extinction of species

Question 22

Cosmopolitan species

Answer 22

Species that have ranges that stretch over several continents

Question 23

Endemic species

Answer 23

Species that have ranges that are isolated to a small area on a single continent

Question 24

Types of Movements

Answer 24

2 main types of movement that organisms do

Question 25

Active movement

Answer 25

Movement that requires an organism to use some appendage to move (walking, flying, swimming, etc)

Question 26

Passive movement

Answer 26

Movement in which an organism uses an external force to cause transit (wind, water, etc)

Question 27

Seed Dispersal

Answer 27

Method by which a plant scatters its offspring away from the parent plant to reduce competition. Methods include: wind, insects, animals, tension, and water - Form of passive movement.

Question 28

Wind (seed dispersal method)

Answer 28

Very light seeds (some have hairy growth acting like parachutes and carrying it far from the parent) are carried to a new place by the wind

Question 29

Water (seed dispersal method)

Answer 29

Ocean currents / rivers carries fruits that float (water lily; coconut palm)

Question 30

Animals / Insects (seed dispersal method)

Answer 30

Animal eats the fruit digesting the juicy part - stones + pips pass through digestive system and are excreted to form new plants - can occur far from parent plant

Question 31

Explosions / Tension / Mechanical (seed dispersal method)

Answer 31

Some plants (lupins, gorse, broom, ripe, bean plants) have pods that explode when ripe and shoot out the seeds

Question 32

Adaptive trait

Answer 32

Behavior / physical feature / characteristic that helps a plant or animal survive and make the most of its habitat

Question 33

Fire

Answer 33

Plants that have adaptive traits that allow them to reproduce or regenerate after surviving fire - Animals have the ability to fly, run away or burrow deep into the ground during fire - Plants can’t so they stores its seeds and disperses them is an example of a fire adaptive strategy. The intensity of the fire is crucial to the seeds dispersal (it is important the fire reaches the right temperature). Also important is how often the fires occur.