2.01 Species and Populations

Question 1

Biotic components

Answer 1

What is living in the system

Question 2

Abiotic components

Answer 2

Non-living in a system

Question 3

Species

Answer 3

Group of organisms that share characteristics and that can also interbreed to produce fertile offspring.

Question 4

Problems arising when defining species

Answer 4

• Sometimes the male and female of the species look very different
• Sometimes different species look identical but can’t interbreed
• Organisms of different species can interbreed to create hybrids.

Question 5

Niche

Answer 5

A match of species to a specific environmental condition where it can thrive. It involves where it lives, breeds, its food, activity patterns and interaction with other species.

Question 6

Habitat

Answer 6

The environment (place) in which a species live, for example woodland habitat. Habitats contains a range of niches.

Question 7

Spatial habitat

Answer 7

Every organisms own space in an ecosystem. The ecosystem also change due to the organisms presence. (E.g. Woodpecker in hollow tree)

Question 8

Fundamental niche

Answer 8

Entire set of conditions under which a population could survive.

Question 9

Realized niche

Answer 9

Is conditions actually used by given population after interactions with other species. Perhaps because of predation and/or competition.

Question 10

When does competition happen related to niches?

Answer 10

The niche that an organism establishes is based on their adaptation or traits for survival. Organisms have to establish their own niche to survive. It is when two niches overlap that competition occurs.

Question 11

Three main types of ecosystems

Answer 11

• Marine
• Freshwater
• Terrestrial

Question 12

Marine systems

Answer 12

The sea, salt marshes, mangrove swamps, saline estuaries.

Question 13

Freshwater systems

Answer 13

rivers and lakes

Question 14

terrestrial systems

Answer 14

land based systems

Question 15

Population

Answer 15

Group of organism of the same species that live in the same area at the same time.

Question 16

Competition

Answer 16

Individuals in an ecosystem are in a competition for food, space and other resources. The organism best suited for the environment will survive and get the resources. Others have to adapt or die.

Question 17

Intraspecific competition

Answer 17

Compete with members of ones own specie

Question 18

Interspecific competition

Answer 18

Compete with members of other species

Question 19

Predation

Answer 19

The interaction between species, where one is a predator and the other is a prey. The change in size of population is clear in this relationship.

Question 20

Population size in relation to predation

Answer 20

Increase in predators—> Decrease in prey—> Decrease in predator—> Increase in prey—>

Question 21

Herbivore

Answer 21

Animals that feed on plants

Question 22

Parasitism

Answer 22

Relationship where parasite benefit from its host, which may suffer from parasite’s presence.

Question 23

Mutualism

Answer 23

Relationship that benefits both organisms. E.g. union between fungus and algae Fungus absorbs minerals and protect algae from drying out. Algae photosynthesis and provides sugar for both.

Question 24

Effects on organisms relationships summarized.

Answer 24

Benefit for both: Mutualism
Benefit for one and harm for one: Predation/parasitism
Harm for both: Competition

Question 25

Limiting factor

Answer 25

Anything that constrains a population’s size and slows or stops it from growing. What a resource becomes when the demand for it is higher than its supply.

Question 26

Carrying capacity

Answer 26

The number of individuals in a population that the resources can support in that environment

Question 27

J-curve

Answer 27

Demonstrates a growth of population where it doesn’t slow down. it shows rapid exponential growth. First time entering a new habitat: Loads of resources = high birth rates and low death rates. The J-curve continues as long as the resources can provide it.

Question 28

S-curve

Answer 28

Shows increase in population in the beginning and then how that slows down due to limiting factors. This is when the population becomes stabilized at a level the environment can support = the carrying capacity of the environment is reached.

Question 29

Phases of the curves

Answer 29

• Exponential growth phase
  No limiting factors so the population can just continue to grow.
• Transition phase
  Resources starts to become limited so the growth speed decreases
• Plateau phase
  Population is now stable at the carrying capacity.

Question 30

Connect curves to feedback

Answer 30

J-curve = positive feedback, increase and increase

S- curve =negative feedback, increase and decrease