Unit 5.2: Natural selection

Question 1

Evolution

Answer 1

The change in heritable characteristics of a population over time

Question 2

Natural selection

Answer 2

Is the theory that explains the process whereby organisms better adapted to their environment tend to survive and reproduce.

Question 3

Biodiversity

Answer 3

Is the variety of life in all of its forms

Question 4

Paradigm

Answer 4

Is a distinct set of concepts and understandings, including theories

Question 5

Paradigm shift

Answer 5

Is a fundamental and dramatic change to scientific understanding

Question 6

Mutation

Answer 6

A change in the nucleotide sequence of a section of DNA coding for a specific trait

Question 7

Sexual reproduction

Answer 7

The fusion of gametes in which each parent contributes half of their genetic material to generate a new combination of alleles

Question 8

Variation

Answer 8

the differences in traits between individuals

Question 9

Genetic variation

Answer 9

the genetic differences that result in different traits between individuals

Question 10

Allele

Answer 10

Alternative forms of a gene that code for the different variations of a specific trait

Question 11

Gene

Answer 11

A heritable factor that consists of a length of DNA and influences a specific characteristic

Question 12

Meiosis

Answer 12

A process consisting of two nuclear divisions in order to produce 4 genetically distinct, haploid nuclei

Question 13

Crossing-over

Answer 13

the process by which non-sister chromatids exchange alleles

Question 14

Independent assortment

Answer 14

Describes how pairs of alleles separate independently from one another during gamete formation

Question 15

Gametes

Answer 15

Sex cells with haploid nuclei

Question 16

Carrying capacity

Answer 16

Is the maximum population of a species that can be supported long term in an environment

Question 17

Competition

Answer 17

An interaction between organisms or species in which both require a resource that is in limited supply

Question 18

Biotic factors

Answer 18

Are living factors that affect the survival of other organisms

Question 19

Abiotic factors

Answer 19

Are non-living parts of an ecosystem that can affect the survival of organisms

Question 20

Selection Pressure

Answer 20

Any reasons for organisms with certain phenotypes to have either a survival benefit or disadvantage

Question 21

Phenotype

Answer 21

The observable traits of an organism resulting from genotype and environmental factors

Question 22

Genotype

Answer 22

The combination of alleles inherited by an organism

Question 23

Density Independent Factors

Answer 23

Factors that limit population growth but are not dependent on population density

Question 24

Intraspecific competition

Answer 24

Competition that occurs within a species

Question 25

Sexual selection

Answer 25

Is natural selection arising through preference by one sex for certain physical or behavioural traits in individuals of the other sex