Chapter 10

Question 1

What’s genetic diversity

Answer 1

number of diff alleles of genes in population.

Question 2

When can natural selection only occur

Answer 2

if there’s genetic diversity within a population.

Question 3

What is natural selection

Answer 3

process that leads to evolution in populations.

results in species becoming better adapted to their enviro.

Question 4

3 types of adaptations

Answer 4

anatomical

physiological

behavioural

Question 5

Natural selection - process

Answer 5

I. New alleles for gene created by random mutations

2. If new alleles increase chances of survival in that enviro, then they more likely to survive and reproduce.
3. This reproduction passes on advantageous allele to next gen.
4. As result, over many gen, new allele increases in freq in population.

Question 6

What are the 2 types of selection

Answer 6

Directional

stabilising

Question 7

Directional selection

Answer 7

• One of the extremes has the selective advantage

• Occurs when there is a change in the environment

• modal trait changes

Question 8

Stabilising selection

Answer 8

. modal traits has selective advantage

• Occurs when there is no change in enviro

• modal trait remains same.

• Standard deviation decreases, as individuals with extreme trait decrease

Question 9

Courtship

Answer 9

essential for successful mating and species recognition.

Question 10

What is a species

Answer 10

group of similar organisms that can breed to make fertile offspring

Species must reproduce, and pass on advantageous alleles, for survival of their species.

Question 11

Courtship rituals

Answer 11

sequence of actions whichs unique to each species. This how animals identify members of their own species to reproduce with.

Most are performed by males.

can include sequence of dance moves, sounds, release of pheromones, display of colourful feathers or fighting.

Females observe courtship ritual and decide if they want to mate with male.

Question 12

importance of courtship to ensure successful reproduction

Answer 12

• Enables them to recognise own species and opposite sex

• Synchronises mating behaviour - indicates sexually mature and in season (releasing egg)

Question 13

Importance of courtship to ensure survivals of the offspring

Answer 13

To ensure survival of the offspring
• Form a pair bond
• Choose a strong and healthy mate

Question 14

Study courtship rituals

Answer 14

The more similar a courtship sequence is between different species, the most closely related a species are.
For example: 3 duck species courtship rituals

Duck I: Shakes tail → shakes beak → nods and swims → turns to female

Duck 2: Shakes tail → shakes beak → flicks head → turns

Duck 3: Shakes tail → whistles → grunts → raises head and tail → turns to female

Duck I & 2 more closely related, as courtship sequence very similar.

Courtship rituals genetically determined, so more similar species sequence is, more similar their DNA base sequence is.

Question 15

What’s the binomial system

Answer 15

First name is GENUS, second name is SPECIES.

Same genus shows close relationship.

Question 16

WHY DO DIFFERENT SPECIES LOOK SIMILAR

Answer 16

1. Live in similar enviro
2. Have similar selection pressures
3. Similar alleles will have selective advantage
4. Produces similar/same proteins and therefore have similar characteristics

Question 17

What is a taxa

Answer 17

Each group of hierarchy

Question 18

What are classification systems examples of

Answer 18

A hierarchy

Question 19

What is a hierarchy

Answer 19

Smaller groups arranged within larger groups

No overlap between groups.

Question 20

Classification systems order

Answer 20

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

Question 21

Why do we need systems to organise the millions of species

Answer 21

Understand relationships between organisms and keep track of changes

system used needs to be universal

Question 22

Ways to classify

Answer 22

Originally, based on visible similarities- e.g. appearance, behaviour, fossils.

More modern and accurate classification methods are:
- DNA sequence
- mRNA sequence
- Amino acids sequence
- Immunological - comparing similarity in self-antibody shape

Question 23

Phylogenetic classification

Answer 23

arranges species into groups according to their evolutionary origins & relationships

Question 24

Phylogeny

Answer 24

tells us who’s related to whom and how closely related they are.

All organisms have evolved from shared common ancestors (relatives).
This shown on phylogenetic tree.

Question 25

Whats species richness

Answer 25

number of diff species in particular area at particular time

Question 26

What’s species diversity

Answer 26

number of different species & individuals within each species in community

Question 27

What’s genetic diversity

Answer 27

variety of genes amongst all individuals in population of 1 species

Question 28

What’s ecosystem diversity

Answer 28

range of diff habitats

Question 29

The importance of biodiversity

Answer 29

can be used to describe range of habitats, from small local habitats to the entire Earth.

low biodiversity might not be a concern - for example you would expect this in the artic or deserts.

decrease in diversity is cause for concern, often caused by human activity.

Question 30

Farming reduces biodiversity

Answer 30

I. Destruction of hedgerows
2. Selective breeding
3. Monocultures
4. Over-grazing
5. Filling in ponds and draining wetlands

Question 31

What’s index of diversity

Answer 31

measure of species diversity

Is a calculation to measure relationship between number of species in community and number of individuals in each species.

Question 32

Index of diversity formula

Answer 32

D = N(N - 1) / sum of n(n - 1)

N = the total number of organisms of all species
n = total number of organisms of a particular species
D = Simpson’s diversity index

1is lowest value for D. larger value for D, the greater species diversity.
is typically between 1- 10.

Question 33

What is evolution

Answer 33

change in allele frequency over many generations in population.