Evolution

Question 1

Mutagens

Answer 1

Physical or chemical agents that induce mutations in DNA are called mutagens and are said to be mutagenic

Question 2

Negative consequences of genetic variation

Answer 2

Only a small % cause genetic disorders—most have no impact on health or development.

Question 3

Positive consequences of genetic variation

Answer 3

A very small % of all mutations actually have a positive effect.
Lead to new versions of proteins that help an individual better adapt to changes in his or her environment.
Eg. a beneficial mutation could result in a protein that protects an individual and future generations from a new strain of bacteria.

Question 4

Taxonomy

Answer 4

used to determine evolutionary relationships between organisms

Question 5

Binomial Nomenclature

Answer 5

Naming species: composed of two parts (scientific name)

Question 6

Carl Linnaeus

Answer 6

Swedish physician and botanist: founder of modern taxonomy.

Question 7

Jean Baptiste Lamarck:

Answer 7

Evolution by use or disuse

Question 8

Darwin’s 2 ideas

Answer 8

Evolution, natural selection

Question 9

Darwin’s 5 points

Answer 9

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 10

Evidence For Evolution

Answer 10

Fossils
Biogeography
Comparative Anatomy
Molecular Biology

Question 11

Evidence from fossils

Answer 11

Fossils in a particular rock are different from rocks above and below = gives them a certain age

Question 12

Index fossils

Answer 12

plant and animals species that lived a short time in geological history, but were wide spread

Question 13

Comparative Anatomy

Answer 13

Comparative anatomy = study of similarities & differences in anatomy of organisms.

Question 14

Homologous Structures

Answer 14

Similar in structure & development but may have different functions.

Question 15

divergent evolution

Answer 15

Implies common ancestor
Differences in structure have evolved in response to different environmental conditions.

Question 16

Analogous Structures

Answer 16

Similar function but no structural relationship.

Question 17

Convergent evolution

Answer 17

structures with different origins have become adapted to a common function.

Question 18

Parallel Evolution

Answer 18

Related species evolve similar features independently.

Question 19

Vestigial Organs

Answer 19

Once useful in an animal’s evolutionary past
Now has no apparent function

Question 20

Limitations of fossils

Answer 20

soft-bodied organisms do not fossilise easily.

only a small fraction of organisms die in conditions favourable to fossilisation.

only a fraction of the fossils have been unearthed.

Question 21

What causes natural selection?

Answer 21

Natural selection happens because there is variation i.e. natural differences in populations.

Question 22

Variation

Answer 22

Variation is caused by differences in genes.

Question 23

Speciation

Answer 23

When one species splits into two or more separate species.

Question 24

Steps of speciation

Answer 24

Variation
Isolation
Selection

Question 25

Physical Isolation

Answer 25

Physical barrier = allopatric speciation Earthquakes, volcanoes, desert formation

Question 26

Temporal Isolation

Answer 26

Breeding at different times to other groups inside a species

Question 27

Behavioural Isolation

Answer 27

Changes in courtship rituals (mating calls)

Question 28

Mechanical Isolation

Answer 28

Mutations that cause physical incompatibility (body parts of pollinators or potential mates)

Question 29

Developmental Isolation

Answer 29

Unviable or sterile offspring

Question 30

gene pool

Answer 30

All the alleles (versions of genes) that exist in a population

Question 31

Allele frequency

Answer 31

How common an allele is in a population.

Question 32

Gene Flow

Answer 32

Movement of genes from one population to another – Due to Migration

Question 33

Genetic Drift

Answer 33

variation in the relative frequency of genotypes in a population (chance, some die or don’t reproduce) – Due to Random Sampling

Question 34

Microevolution

Answer 34

Survival through the inheritance of favourable traits (genes). Results in changes within a population

Question 35

Macroevolution

Answer 35

Progression of biodiversity over geological time. Results in new species