Chapter 2 Key Terms

Question 1

A variation of a specific gene.

Answer 1

Allele

Question 2

The first 22 pairs of chromosomes

Answer 2

Autosomes

Question 3

The branch of genetics that deals with the inheritance of behavioural and psychological traits.

Answer 3

Behavioural Genetics

Question 4

A technique using clustered, regularly interspaced short palindromic repeats to edit genes.

Answer 4

CRISPR

Question 5

Thread-like structures in the nucleus of the cell that contain genetic material

Answer 5

Chromosomes

Question 6

A molecule composed of four nucleotide bases; DNA is the biochemical basis of heredity

Answer 6

Deoxyribonucleic Acid (DNA)

Question 7

Twins that are the result of the fertilization of two separate eggs by two sperm

Answer 7

Dizygotic (fraternal) Twins

Question 8

The form of an allele whose chemical instructions are followed

Answer 8

Dominant Allele

Question 9

A disorder caused by an extra 21st chromosome that results in intellectual disability and a distinctive appearance

Answer 9

Down syndrome

Question 10

The continuous interplay between genes and multiple levels of the environment (from cells to culture)

Answer 10

Epigenesis

Question 11

A group of nucleotide bases that provide a specific set of biochemical instructions

Answer 11

Gene

Question 12

A person’s hereditary makeup

Answer 12

Genotype

Question 13

A disorder in which the blood does not clot easily, and sufferers can bleed severely from even minor injury

Answer 13

hemophilia

Question 14

An estimate of the extent to which differenced among people reflect heredity

Answer 14

Heritability Coefficient

Question 15

The condition in which the alleles for hereditary characteristics differ from each other.

Answer 15

Heterozygous

Question 16

The condition in which the alleles for hereditary characteristics are the same

Answer 16

Homozygous

Question 17

A type of dementia caused by a dominant allele characterized by degeneration of the nervous system.

Answer 17

Huntington’s disease

Question 18

The situation in which one allele does not dominate another completely.

Answer 18

Incomplete Dominance:

Question 19

The technique of fertilizing eggs with sperm in a Petri dish and then transferring several of the fertilized eggs to the mother’s uterus, where they might implant in the lining of the uterine wall

Answer 19

In Vitro Fertilization

Question 20

Twins that result when a single fertilized egg splits to form two new individuals.

Answer 20

Monozygotic (identical) Twins

Question 21

A process by which experience changes the expression of DNA- the genetic code is preserved, but a gene is silenced by a methyl molecule

Answer 21

Methylation

Question 22

The process of deliberately seeking environments that are compatible with one’s genetic makeup

Answer 22

Niche-picking

Question 23

Forces in the immediate environment (e.g, within a family) that make children different from one another

Answer 23

Nonshared Environmental Influences

Question 24

The physical, behavioural, and psychological features that are the result of the interaction between one’s genes and the environment

Answer 24

Phenotype

Question 25

When phenotypes are the result of the combined activity of many separate genes.

Answer 25

Polygenic Inheritance

Question 26

The phenomenon is that a particular genotype can interact with various environments to produce a range of phenotypes.

Answer 26

Reaction Range

Question 27

An allele whose instructions are ignored when it is combined with a dominant allele

Answer 27

Recessive Allele

Question 28

The 23rd pair of chromosomes which determine the sex of the child

Answer 28

Sex Chromosomes

Question 29

When a genetic disorder is linked to a gene carried by one of the sex chromosomes.

Answer 29

Sex-linked

Question 30

A disorder in which individuals show signs of mild anemia only when they are seriously deprived of oxygen; it occurs in individuals who have one dominant allele for normal blood cells and one recessive sickle-cel allele.

Answer 30

Sickle-cell Trait