Module 3 - BIOLOGICAL DIVERSITY

Question 1

what is an ecosystem?

Answer 1

ecosystem is the combination of all the organisms (biotic factors) living in a community (a group of
different populations in an area or habitat) and all the non-living features (abiotic factors) with which they
interact.

Question 2

what abiotic factors are aquatic environments affected by?

Answer 2

salt concentrations, light availability, pressure

Question 3

what are some examples of terrestrial ecosystems?

Answer 3

desert, grassland, shrubland, woodland, temperate forest, tropical rainforest.

Question 4

what are some examples of selection pressures?

Answer 4

• abiotic factors such as temperature, light intensity, soil type, water
  availability and gas concentration in water
• biotic factors such as competition between members of a species for the same limited resources, predators and availability of prey.

Question 5

what is distribution and abundance?

Answer 5

• The distribution of a species describes where it is found
• the abundance of a species determines
  how many individuals of that species live throughout the ecosystem.

Question 6

what is ecology?

Answer 6

is the study of interrelationships between different types of organisms and between organisms and their environment.

Question 7

why do ecologists study abundance and distribution?

Answer 7

variety of reasons, including assessing biodiversity so that management plans can be put into place before development and land clearing goes ahead
in environments such as coastal areas, bushland and natural grasslands and forests.

Question 8

how to calculate plant abundance?

Answer 8

sampling techniques such as quadrats.

Question 9

formula for estimated abundance in an area?

Answer 9

= total number of individuals counted / area of each quadrant x number of quad.
x total area.

Question 10

how to calculate animal abundance?

Answer 10

a sampling technique called the mark–release– recapture technique.

Animals are captured; the sample animals are tagged and then released; these
animals are given time to mix again, another sample is captured, and the number tagged in the second
the sample is counted.

Question 11

The formula for animal abundance?

Answer 11

= number captured x number recaptured/ number marked in recapture

Question 12

how is the distribution of a species measured?

Answer 12

• transects are commonly used to give an idea of how a variation may occur
• A transect is a narrow strip that crosses the entire area being studied from one side to the other.

Question 13

what is adaptation?

Answer 13

a characteristic that an organism has inherited and that makes it suited to its
environment. An organism does not intentionally change to suit its environment, nor can it intentionally
produce offspring that have these changes.

Question 14

what are the three types of adaptations?

Answer 14

structural - how an organism is built

physiological - how an organism functions

behavioural - how an organism behaves or acts.

Question 15

structual adaptation and example (plant and animal)

Answer 15

is to do with how the organism is built or structured, and how this aids their survival in their natural habitat. Structural adaptations are physical features, on both the inside and outside of an organism.

• The webbed feet of a platypus enable it to swim fast

-thin, pointed leaves on spinifex grass reduce water loss

Question 16

physiological adaptation and an example (plant and animal)

Answer 16

are adaptations related to how organisms function that increase the organisms’ chances of survival in their natural environment. They involve variations in the metabolism or physiology of
organisms at a cellular, tissue, organ or system level, giving them specific advantages for a particular
set of environmental circumstances.

• example, the intertidal marsh crab has gills and kidneys that function to concentrate and excrete excess salt.
• Plant cells found in the growing tips of stems are sensitive to the hormone
  auxin, which causes them to grow towards light.

Question 17

behavioural adaptations and an example (plant and animal)

Answer 17

adaptations refer to those actions performed by an organism in response to a stimulus that improve its chances of survival.

• puffer fish are able to pump air into their stomachs and blow up to twice their size to frighten predators.
• The Venus flytrap is a plant that is adapted to live in nitrogen-poor soils.
  It is able to act rapidly when a small insect alights on it. Part of the plant is able to snap shut when the insect touches delicate sensory hairs.

Question 18

what is biodiversity?

Answer 18

refers to the variety of all forms of life on Earth, the diversity of the
characteristics that living organisms have and the variety of ecosystems of which they are components.

Question 19

what is genetic diversity?

Answer 19

which refers to the total number of genetic characteristics in the genetic make-up of a species

Question 20

what is species diversity?

Answer 20

which is a measure of the diversity of different species in an ecological
community

Question 21

what is ecosystem diversity?

Answer 21

which is the variation of different ecosystems found in a region.

Question 22

examples of genetic diversity?

Answer 22

calicivirus that affected rabbits and was used to control population numbers. some rabbits however survived due to an inherited resistance. It is these rabbits that will go on to reproduce and pass that genetic characteristic onto their offspring.

Question 23

what is the Darwin–Wallace Theory of Evolution by Natural Selection?

Answer 23

based on the premise that living things
arose from a common ancestor and that some populations moved into new habitats where they adapted
over time to their environments, leading to the diversity of life.

Question 24

what does natural selection depend on?

Answer 24

◗ variability: all populations have random differences or variations among their members

◗ heritability: variation may be inherited

◗ over-reproduction: organisms produce more offspring than the environment can support (that is, not all offspring survive)

◗ competition between organisms and survival of the fittest.

Question 25

what is speciation?

Answer 25

the formation of new species.

Question 26

what is allopatric speciaction?

Answer 26

speciation that occurs when populations become isolated.

Question 27

stages of allopatric speciation?

Answer 27

1. The parent pool has a large range and regular flow of genes
2. part of the population becomes separated
3. two populations experience different selection pressures that favour some individuals. isolated population becomes a subspecies.
4. if separated long enough the gene pool of each population will change. gene flow will not occur. the may become so different they cannot breed together

Question 28

what is macroevolution?

Answer 28

Macroevolution takes place over millions of years, measured as geological time, and results in new species (and even larger groups such as new families and orders) arising.

Question 29

what is microevolution?

Answer 29

Microevolution takes place over shorter periods and results in changes within populations, but it
generally does not produce new species. New forms that arise within populations are sometimes referred to as varieties or races. An example is the different breeds of dogs, which all belong to the
same species. (This form of evolution is most commonly seen in current short-term studies of living
organisms.)

Question 30

what was the first horse like and what was its name?

Answer 30

Hyracotherium:
- doglike
- long tail
- short legs
- ate fruit and soft plants
- short diastema and low-crowned teeth
- had four phalanges

Question 31

what are the medium-sized horses called and why did their features change?

Answer 31

include Miohippus and Mesohippus.

• the climate got drier, forests started shrinking and grasses became more prevalent.
• selection pressure to eat tougher plant materials, to increase in size and to move
  faster through the grasslands.
• had 4 phalanges

Question 32

what were the horses of the Miocene called and what did they change?

Answer 32

Merychippus.

• a gradual increase in the height of teeth crowns and horses became better at
  running, with an increase in both body size and length.
• 3 phalanges

Question 33

what were the last two horses called?

Answer 33

Pliohippus, and Equus

Question 34

what are vestigial strutures?

Answer 34

thought to be evolutionary remnants of body parts that no longer serve a useful function within that population.