C8 - Evolution

Question 1

What are mutagens?

Answer 1

Physical or chemical agents that can induce mutations in DNA

Question 2

What are some examples of positive changes mutations can cause?

Answer 2

Creating new versions of proteins that help and individual better adapt to their environment

Question 3

How can a mutation be negative?

Answer 3

Can cause genetic disorders

Question 4

What are most genetic mutations?

Answer 4

Neutral, in that they don’t create any observable change

Question 5

What is binomial nomenclature?

Answer 5

The method of naming species, created by Carl Linneaus (in 1707) and founded modern taxonomy

Question 6

What does Genus mean?

Answer 6

General

Question 7

What does species mean?

Answer 7

Specific, and can create viable offspring with each other

Question 8

What is taxonomy?

Answer 8

Used to determine evolutionary relationships between organisms

Question 9

What was Lamarck’s 1801 theory of evolution

Answer 9

Use it or lose it mentality, with portions of animal that are not used within their lifetime becoming smaller or disappearing, and parts that are more heavily used becoming larger.

Question 10

What is an example that ‘proved’ Lamarck’s theory?

Answer 10

The giraffe, who stretched it’s neck to reach leaves, resulting in a longer neck that was passed on to offspring

Question 11

Problems with Lamarck’s theory of evolution

Answer 11

We now know that traits acquired over an individual’s lifetime (i.e. muscles) cannot be passed onto offspring

Question 12

When did Darwin publish “Origins of Species”?

Answer 12

1859

Question 13

What were the two main ideas of Darwin’s theory?

Answer 13

Species are not created in their present form, but evolved from an ancestral species, and Natural selection as a mechanism for evolution

Question 14

What are Darwin’s 5 points?

Answer 14

1: Population has variations
2: some variations are favourable
3: More offspring are produced than survive
4: Those that survive have favourable traits
5: A population will change over time

Question 15

What is the evidence for evolution?

Answer 15

Fossils, correlation between rock and fossil age, biogeography, comparative anatomy

Question 16

What are homologous structures?

Answer 16

Similar in structure and development but may have different features (wing of a bird and flipper of a whale), imply a common ancestor

Question 17

What are analogous structures?

Answer 17

Similar function but no structural relationship (wing of a bird and an insect - same function - flight, but no structural relationship) - implies these two groups have different ancestral origins

Question 18

What are vestigial organs?

Answer 18

Once used in an animals evolutionary past, but not anymore, like the pelvis on a whale

Question 19

What is comparative embryology?

Answer 19

Comparing embryos to see similarities

Question 20

What are some limitations to fossils?

Answer 20

Many gaps in fossil record and the chance of an organism being fossilized is very low

Question 21

What are index fossils?

Answer 21

A plant or animal that lived for a relatively short time but was widespread, indicating it was the ‘fittest’ at the time

Question 22

How are fossils evidence for evolution?

Answer 22

The older the rock, the older the fossil, and there are a variety of fossils in each layer of rock - fossils are different to those in upper and lower levels of rock, giving them a certain age

Question 23

What is biogeography?

Answer 23

Patterns in species distribution, shows geographical fragmentation of ancestral species, along with continental drift and consequential isolation of populations

Question 24

What is comparative anatomy?

Answer 24

Study of similarities and differences in anatomy of organisms - main concept is homologous and analogous structures

Question 25

What is convergent evolution?

Answer 25

structures with different origins have evolved the same function (bird and insect)

Question 26

What is parallel evolution?

Answer 26

Related species form similar features independently

Question 27

What is natural selection?

Answer 27

Individuals with favourable traits are selected and are more likely to thrive and produce more offspring, passing down the trait in DNA to future generations

Question 28

What is variation?

Answer 28

Natural differences in populations caused by genes

Question 29

What is speciation?

Answer 29

When one species splits into two or more separate species - why there is biodiversity on earth

Question 30

What are the three steps to speciation?

Answer 30

1: variation
2: Isolation
3: Selection

Question 31

What is isolation?

Answer 31

Required for a new species to form (Grand Canyon Squirrel)

Question 32

What are the five types of isolation?

Answer 32

Physical isolation (barrier - earthquake etc)
Temporal isolation (breeding at different times to other groups inside species)
Behavioural isolation (change in courtship rituals)
Mechanical isolation (incompatibility of a physical nature)
Developmental isolation (after copulation - offspring is not viable)

Question 33

What is the gene pool?

Answer 33

All the alleles that exist in a population

Question 34

What is allele frequency?

Answer 34

How common the allele is within the population

Question 35

What is gene flow?

Answer 35

Movement of genes from one population to another - due to migration

Question 36

What is genetic drift?

Answer 36

Variation in the relative frequency of genotypes in a population - due to random sampling

Question 37

What is microevolution?

Answer 37

Survival through inheritance of favourable genes (traits) - results in changes within a population

Question 38

What is macroevolution

Answer 38

Progression of biodiversity of geological time and results in new species, caused by speciation/extinction