Genetic Diversity and adaptation

Question 1

How can genetic diversity be caused?

Answer 1

1) gene mutation
2) chromosome mutation
3) random factors associated with meiosis, fertilisation and mating

Question 2

Phenotypic Variation

Answer 2

Differences in phenotypes in a population/species

Question 3

Population

Answer 3

Organisms of the same species in the same habitat

Question 4

Genetic Diversity

Answer 4

-measure of the number of different alleles that are present in a population
-allows for the process of natural selection to occur resulting in a species that is best adapted to its environment

Question 5

3 types of biological adaptation

Answer 5

1) anatomical (structural)
2) physiological (relates to internal functions of organs, tissues, cells and biochemistry)
3) behavioural

Question 6

Allele frequency during natural selection

Answer 6

Frequency will increase in the population as less advantageous individuals without the allele will exist and those with the advantageous allele will increase in numbers.

Question 7

Evolution

Answer 7

• a change in the characteristics of a species across several generations, sometimes leading to the development of a new species from pre-existing one

Question 8

Polygenic traits

Answer 8

-most genetic traits are polygenic meaning they are due to multiple action of many genes and there protein product.
-example is variation in size
-can be presented using a histogram or density plot

Question 9

Steps of natural selection

Answer 9

1) Random mutation - new alleles of a gene
2) Threat to survival - competition, predation, lack of food , disease, change to environmental conditions
3) Natural selection - some individuals are better adapted
4) Reproduction - better adapted individuals will survive to breed
5) Increase in allele frequency - advantageous alleles will increase in frequency and less advantageous alleles will decrease

Question 10

3 Types of natural selection

Answer 10

1) Directional
2) Stabilizing
3) Disruptive

Forms a normal distribution curve on a graph which can then be used to identify the type of selection

Question 11

Directional Selection

Answer 11

Allele frequency moves towards one phenotype extreme and away from the other

Question 12

Stabilising Selection

Answer 12

Allele frequency moves towards the mean value/phenotype and against both phenotype extremes

Question 13

Disruptive Selection

Answer 13

Allele frequency moves towards both extremes of the phenotype and away from the mean value/phenotype

Question 14

How do 2 organisms belong to the same species

Answer 14

If they are able to reproduce fertile offspring

Question 15

What is courtship?

Answer 15

Includes a wide range of behaviours in the natural world that lead to a ‘successful mating between a male and female of the same species.

Question 16

What does courtship allow for?

Answer 16

-Natural selection through sexual selection. This will allow unique characteristics that cause a natural attraction to be detected. These attributes may be quite random or predictable.

Question 17

Reasons for courtship behaviour

Answer 17

1) To identify members of the same species
2) To approach one another without aggression
3) recognition and attraction to mate of opposite sex
4) indicates fertility or readiness to mate
5) helps to form pair bond

Bird song is an example of this

Question 18

What is classification?

Answer 18

-process of arranging organisms, both living and extinct, into groups based on similar characteristics.

-Each group is known as a taxon (plural taxa)

-groups do not overlap

Question 19

2 types of classification

Answer 19

1) Artificial
2) Phylogenic

Question 20

Artificial Classification

Answer 20

This groups organisms according to the similarities and differences that are useful at the time e.g size, colour leaf shape, number of legs etc. e.g The Linnaen System of classification.

Not based on evolutionary relationships

Question 21

Artificial Classification Example

Answer 21

5 Kingdom System-
Animal
Plant
Fungi
Protist
Prokaryote

Question 22

Phylogenic Classification

Answer 22

-groups organisms according to their evolutionary relationships. Often these can be represented on a phylogenetic tree.

Question 23

Phylogenic Classification Example 1

Answer 23

3 Domain System -
-developed by Carl Woess domain system after noticing that there were 2 distinct types of prokaryotic cells with very different structural features

Archaea - are actually more closely related to eukaryotic cells (similar metabolic pathways). They have a much more diverse range of energy sources.
Bacteria
Eukaryotes

Question 24

Phylogenic Classification Example 2

Answer 24

Biological Hierarchy of Classification
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 25

What is a species?

Answer 25

-A group of organisms that can interbreed to produce fertile offspring
-The most diverse taxon

Question 26

Binomial Names

Answer 26

Consists of organisms genus and species