Chapter 1

Question 1

What is a characteristic?

Answer 1

A feature of an organisms.

Question 2

What is variation?

Answer 2

Differences in characteristics.

Question 3

What are the two types of variation?

Answer 3

Genetic + environmental

Question 4

What is a species?

Answer 4

A group of organisms with similar characteristics that mate to produce fertile offspring.

Question 5

What is a gene?

Answer 5

A sequence of DNA that codes for specific characteristics.

Question 6

What does DNA stand for?

Answer 6

Deoxyribonucleic acid.

Question 7

What is a genotype?

Answer 7

All the genes found in an organism.

Question 8

What is an allele?

Answer 8

Different versions of the same gene.

Question 9

What is a phenotype?

Answer 9

The development of physical characteristics controlled by the genes (observable traits).

Question 10

True or false: A phenotype can also be changed by the environment.

Answer 10

True.

Question 11

What is a genome?

Answer 11

The complete set of genetic instructions (genes) in that cell or organism.

Question 12

What is a mutation?

Answer 12

A change in the sequence of DNA.

Question 13

What mutation did the Malpeque oysters have?

Answer 13

They became immune to the disease.

Question 14

What mutation did the peppered moths have?

Answer 14

They changed colour for protection against predators.

Question 15

What were Darwin’s main ideas?

Answer 15

1. Individuals in species vary in traits.
2. Reproduction produces too much off spring for the environment to support.
3. The ones most likely to survive and reproduce were those fittest for the environment.

Question 16

What is natural selection?

Answer 16

A process where organisms that are better to an environment will survive and reproduce. This is also known as survival of the fittest.

Question 17

Why does variation exist?

Answer 17

It exists due to random mutations in ones genome.

Question 18

What are the steps of survival of the fittest?

Answer 18

1. Organisms in a species show genetic and phenotypic variation.
2. Those who are more fit for the environment are more likely to survive and reproduce.
3. These good alleles are passed on.
4. If two populations of the same species become so different, they form two new species.

Question 19

What adaptations can improve survival?

Answer 19

Structural (physical), functional (physiological or chemical), or behavioural (actions that aid survival).

Question 20

When did life first develop?

Answer 20

3 billion years ago.

Question 21

What did the first life develop from?

Answer 21

Simple life forms - Protoctists.

Question 22

What is evolution?

Answer 22

The change in the inherited characteristics of a population over time, through the process of natural selection.

Question 23

What does the gene pool of a population determine?

Answer 23

Which phenotypes are present at any given time.

Question 24

What is the evidence of evolution?

Answer 24

1. Anatomy and embryology
2. Biogeography
3. Fossils
4. Direct observation

Question 25

What are the causes of extinction?

Answer 25

Natural causes, catastrophic event, human impact, inability to adopt to change in environment, overfishing and new predators.

Question 25

What are the consequences of mass extinction in evolution?

Answer 25

1. Death of several species + eliminates whole chains of organisms. 2. Gives surviving species an opportunity to diversify and evolve.

Question 26

Why did life move from sea to land?

Answer 26

Because of the ozone layer.

Question 27

What are stromolites?

Answer 27

Primitive single-celled bacteria grouped together in multicellular mats.

Question 28

What are the advantages of being multicellular?

Answer 28

1. Can grow larger because they can diffuse gases and nutrients. 2. They avoid duplication of work and save energy because they have specialized cells. 3. Increases survival chances because it doesn't atter if a few cells die. 4. Specialized cells form tissues, improving efficacy. 5. They live longer due to division of labour. 6. They can regulate internal environment and adapt to environmental changes. 7. Sexual reproduction leads to genetic variation, therefore survival chances are increased.

Question 29

What is a eukaryotic cell?

Answer 29

A cell that has a nucleus and specialized membrane-bound organelles.

Question 30

What is a prokaryotic cell?

Answer 30

A cell that lacks a nucleus and membrane-bound organelles.

Question 31

What does the endosymbiotic theory explain?

Answer 31

Certain organelles, like mitochondria and chloroplasts, originated from free-living bacteria that were engulfed by a host cell in a mutualistic relationship.

Question 32

What is the evidence for the endosymbiotic theory?

Answer 32

1. Chloroplasts and mitochondria are the same size as the prokaryotes and divide like them. 2. Similar to bacteria, they have their own circular DNA. 3. Their ribosomes resemble those of prokaryotes. 4. They have multiple membranes and their inner one is similar to the prokaryotic membranes. 5. Some primitive eukaryotes have a nucleus but no mitochondria.