Unit 3

Question 1

Habitat

Answer 1

The place where an organism usually lives

Question 2

Population

Answer 2

All the organisms of one species in a particular habitat

Question 3

Community

Answer 3

All the populations of different species living in the same place at the same time

Question 4

Ecological Niche

Answer 4

The role of an organism within its environment
This includes how it:
- Obtains energy
- Interacts with other species
- Interacts with its environment

Question 5

Ecosystem

Answer 5

The combination of all the abiotic and biotic factors in a particular area
It is a self sustained system (mainly) so it only needs little energy or matter flowing in and out of it and no external energy source, this is because it functions due to photosynthesizing organisms.

Question 6

Microhabitat

Answer 6

A small, localized habitat within a larger habitat
There can be several microhabitats in a single area.
Each microhabitat has different characteristics which give it its own microclimate

Question 7

Ecoregion

Answer 7

A large area that has a distinct geography and contains a collection of organisms which are distinct from the area next to it.
Ecoregions differ based on their climate, geology, and the organisms that live there.

Question 8

Carrying capacity

Answer 8

The maximum stable population size that can be maintained over a period of time in a habitat

Question 9

Limiting factors that can influence carrying capacity

Answer 9

Biotic: Predation and Competition
Abiotic: Temperature, Light, pH, Water + Humidity and Area size

Question 10

Population Size

Answer 10

The number of organisms from the same species in a habitat

Question 11

Population Growth Rate

Answer 11

How quickly the size of a population changes over time

Question 12

Population Growth Rate Equation

Answer 12

Change in population/Length of time

Question 13

The stages of population size

Answer 13

1. New population settles into an environment
2. Birth and immigration exceeds death and emigration
3. Density dependent factors slow population growth
4. Population reaches carrying capacity

Question 14

J Curve

Answer 14

There is a rapid increase in growth which is followed by a sudden drop
‘BOOM and then a bust’

Question 15

Ectotherm

Answer 15

Organisms that cannot control their internal temperature

Question 16

Endotherm

Answer 16

Organisms that can control their internal temperature

Question 17

Photosynthesis

Answer 17

Plants convert light energy into chemical energy

Question 18

Competition

Answer 18

Competition always exists when more than one individual wants the same limited resource

Question 19

Interspecific Competition

Answer 19

When organisms from different species compete for the same resources
It can impact the distribution of species and the population size

Question 20

Distribution of species

Answer 20

If one species is better adapted and able to obtain more resources, it will out-compete the other species
The population size of the less-suited species will fall, or species could occupy a new niche

Question 21

Intraspecific Competition

Answer 21

Organisms from the same species compete for the same resources
It is more common than interspecific competition
Consequences include:
- Fluctuation in population size around the carrying capacity

Question 22

Symbiosis

Answer 22

A close prolonged relationship between organisms of different species
At least one organism must benefit from this relationship
The three types of symbiotic relationships are:
1. Mutualism
2. Commensalism
3. Parasitism

Question 23

Mutualism

Answer 23

Both organisms benefit from the relationship

Question 24

Commensalism

Answer 24

One organism benefits, and the other is unaffected

Question 25

Parasitism

Answer 25

One organism benefits, and the other is harmed

Question 26

Amensalism

Answer 26

One organism is unaffected and the other is harmed

Question 27

Biodiversity

Answer 27

The variability among Earths living organisms, can exist as:
Ecosystem Biodiversity
Species Diversity
Genetic Diversity

Question 28

Spatial Comparison

Answer 28

Comparing Biodiversity over an area

Question 29

Temporal Comparison

Answer 29

Comparing Biodiversity over time

Question 30

Species

Answer 30

1. A group of organisms which can interbreed to produce live, fertile offspring
2. A group of organisms with morphological or genetic similarity

Question 31

Biological Classification

Answer 31

A way of organising organisms so that closely related organisms are grouped together

Question 32

Linnaean Classification- Taxonomic Groups

Answer 32

Do- Domain
Keep- Kingdom
Practicing- Phylum
Classifying- Class
Organisms- Order
For- Family
Guaranteed- Genus
Success- Species

Question 33

Sexual Reproduction- K

Answer 33

Involves 2 parent organisms each providing a sex cell
In fertilizations, genetic material combines to form a new unique cell that develops into an organism

Question 34

Asexual Reproduction- R

Answer 34

Involves 1 parent organism
No fertilisation takes place and no new genes are created
Offspring is genetically identical to the parent

Question 35

Phylogenetic Trees

Answer 35

Phylogenetic trees are structures that display the evolutionary relationships between organisms

Question 36

Cladograms

Answer 36

Cladograms are structures based largely on morphological characteristics of organisms that predict the evolutionary relationship between groups of similar looking organisms