chapter 9 - genetic diversity and adaptation

Question 1

How were classification system’s formed and how are they different now

Answer 1

Classification systems used to be based on observable features however now we use genetic comparisons that can be made by different species by direct examination of the base sequence of DNA, the base sequence of mRNA all the proteins encoded by DNA and mRNA

Question 2

What is biodiversity/biological diversity

Answer 2

It is reflected in the vast number of species of organisms, these different says reflect genetic differences in the variation of individual characteristics within a single species

Question 3

What is genetic diversity

Answer 3

The total number of alleles of a gene in a population. The greater the number of alleles the greater the genetic diversity of that species. enables natural selection to occur

Question 4

What is allele frequency

Answer 4

How often a particular allele appears in a population

Question 5

What is the cause of genetic diversity

Answer 5

All members of the same species have the same genes. Organisms differ in the alleles. It is a combination of alleles in an organism that makes individuals within a species different from each other.

Question 6

Changes in genetic Diversity

Answer 6

Genetic diversity within a species can be caused by, a random mutation in the DNA resulting in new alleles of a gene.

Question 7

Why do we use phylogenetics

Answer 7

To see how closely related the organisms among various taxonomic groups are. It assumes that’s all organisms have an evolutionary history that’s began with an ancestor

Question 8

What is DNA hybridization

Answer 8

Allows scientists to find similarities between the DNA of different species.

1) DNA from the two species is extracted, purified and cut into shorter pieces
2) The DNA of one of the organisms is labeled with a fluorescent radioactive marker and then is mixed with the unlabeled DNA to be compared against.
3) The mixture is heated to allow DNA strands to disassociate and become single strands
4) The mixture is allowed to cool so that’s DNA strands with complementary base sequences combine

hybridised sequences with a greater similarity will have more base pairing and will bind more firmly.

after. mixtures are heated again at temperature increments to analyze how many stands have separated from their hybrid.

less hybridization, more different the two DNAs are

Question 9

Describe the process of natural selection

Answer 9

Within a population that is a gene pool with a variety of alleles. However in certain environments there may be an allele with a advantage over other individuals in a population. These individuals are more likely to obtain available resources and grow rapidly and live longer, they are better adapted to survive. These individuals have a better chance of breeding. Only individuals that reproduce successfully will pass on their alleles. Therefore they new allele passed to the parents is most likely going to pass on to the next generation. as new individuals have the advantageous allele they are more likely to survive and reproduce successfully. Over many generations the number of individuals with the new Allele will increase. Overtime the frequency of the new advantageous allele in the population increases while that’s of the non-advantageous allele decreases.

Question 10

Behavioral and behavioral adaptations

Answer 10

Behavioral-These are acts which an organism does to increase its chances of survival and reproduction.

Behavioral adaptations-When a hedgehog is startled It curls into a ball with its spikes up. huddling reduces surface area to volume ratio, reducing heat loss.

Birds keep themselves warm by cuddling with each other

Question 11

Physiological and physiological adaptations

Answer 11

physiological-Processes inside and organisms body that increases its chance of survival and reproduction

Physiological adaptations-Arctic fish contain an anti-freeze protein which prevents them from freezing in very cold waters, therefore they are able to survive and reproduce and pass on this beneficial gene to their offspring.

Question 12

Anatomical and anatomical adaptation

Answer 12

Anatomical-Structural external features which increase an organisms chance of surviving and reproducing

Anatomical adaptations-Common wombat,They have small ears and short strong legs. Sharp claws for digging borrows, rounded body weight. Females have a pouch were Young can grow and be protected.

Question 13

Define evolution

Answer 13

Evolution is The gradual change an allele frequency Within a population over time. occurs due to natural selection

Question 14

what is the niche of a species

Answer 14

The role within the environment. Species which share the same niche compete with each other

Question 15

Describe and explain directional selection

Answer 15

Happens when the environmental conditions change and the phenotypes best suited to the new conditions are more likely to survive. And these individuals breed and produce offspring. Overtime the mean of the population will move in the direction of these individuals. the change is in One Direction

Question 16

Describe and explain stabilizing selection

Answer 16

In stabilizing selection the phenotypes with successful characteristics are preserved and those of greater diversity are reduced. However the selection does not occur due to changes in the environment. If the environment stays the same then the individuals closest to the mean are favored because they have the alleles that have given them the survival advantage. The furthest from the mean are selected against.

Question 17

When does directional selection occur

Answer 17

When there is a change in environment

Question 18

When does stabilising selection occur

Answer 18

When there is no change in environment

Question 19

Why is a low biodiversity possibly not a concern by decrease in diversity a cause for concern

Answer 19

hello biodiversity might not be a concern for example you would expect this in an Artic or in desert conditions

however a decrease in diversity is a cause for concern, and this is often caused by human activity

Question 20

What are five farming techniques that reduce biodiversity

Answer 20

destruction of hedgerows
selective breeding
monocultures
overgrazing
Filling in ponds and draining wetlands

Question 21

How do you interpret the diversity index

Answer 21

The lowest value you can get for the diversity index is one

The larger the value for the diversity index means of the greater the species diversity

Question 22

Investigating diversity: you can investigate genetic diversity within or between species by comparing:

Answer 22

The frequency of observable characteristics
The base sequence of DNA The base sequence of mRNA
Amino acid sequence of proteins

Question 23

Why does destruction of hedgerows reduce biodiversity

Answer 23

this destroys a habitat for local species and small mammals and insects in the area

Question 24

How does selective breeding reduce biodiversity in the area

Answer 24

Plants or animals that display desirable characteristics of selectively bred to reproduce therefore the desirable characteristic is displayed in the next generation. however this narrows down the gene pool and you don’t have as much biodiversity/diversity in the area

Question 25

How do monocultures reduce biodiversity in the area

Answer 25

This is where you grow only one type of plant species in a specific area. This immediately reduces the diversity in the area. Monocultures also attract only one type/a few types of species of insects into the area. This further decrease as the diversity of the area

Question 26

Why does overgrazing lead to a reduction in biodiversity

Answer 26

if the animals are left over Greece in a specific area which reduces the yield/mass of crop in the area

Question 27

Why does filling in ponds and draining wetlands reduce biodiversity in an area

Answer 27

This eliminates a habitat for some species/insects/animals in an area. This decreases biodiversity however it needs to be done as space is needed for crops to grow