Vocabulary

Question 1

Chromosome

Answer 1

A threadlike structure made of protein and a single molecule of DNA that serve to carry the genomic information from cell to cell.

Question 2

Homologous

Answer 2

The two chromosomes in a homologous pair are very similar in size and shape, and carry the same genes in the same locations, although they do not necessarily have the same versions of genes (different alleles)

Question 3

Diploid

Answer 3

The presence of two complete sets of chromosomes in an organism’s cells, with each parent contributing a chromosome to each pair

Question 4

Haploid

Answer 4

A cell that contains a single set of chromosomes

Question 5

Ova

Answer 5

Unfertilised female gamete

Question 6

Sperm

Answer 6

Male gamete

Question 7

Fertilisation

Answer 7

• Union of two gametes
• Sperm and egg fuse to form a diploid zygote to initiate prenatal development

Question 8

Zygote

Answer 8

The fertilized egg cell that results from the union of a female gamete with a male gamete

Question 9

Mutations

Answer 9

• A change in the DNA sequence of an organism
• Can result from errors in DNA replication during cell division, exposure to mutagens, or a viral infection

Question 10

Gene

Answer 10

A stored set of instructions for a protein, found on a specific locus (position) on a chromosome

Question 11

Allele

Answer 11

• A form of a gene
• Different alleles code for different versions of the same trait
• Pairs of alleles are found on a set of maternal and paternal homologous chromosomes

Question 12

Karyotype

Answer 12

An individual’s complete set of chromosomes

Question 13

Locus

Answer 13

The physical site or location of a specific gene on a chromosome

Question 14

Homozygous

Answer 14

• Possessing two identical alleles of a gene
  □ AA is a homozygous dominant genotype
  □ aa is a homozygous recessive genotype

Question 15

Heterozygous

Answer 15

Possessing two different alleles of a gene

Question 16

Genotype

Answer 16

• The genetic composition of an organism for a particular trait
• The set of alleles (one from each parent) that an organism has for a particular trait

Question 17

Phenotype

Answer 17

• An individual’s observable traits, such as height, eye colour, etc
• Determined by genetic makeup and environmental factors

Question 18

Dominant

Answer 18

• Always expressed in the phenotype
• Masks a recessive allele if paired with one
• Has the same effect on the phenotype whether it is paired with the same allele or a different one
• Represented by a capital letter

Question 19

Recessive

Answer 19

• Only expressed in the phenotype when homozygous (present with the same allele e.g. aa)
• Is masked by the dominant allele
• Represented by a lowercase letter

Question 20

Monohybrid cross

Answer 20

A hybrid of two individuals with homozygous genotypes which result in the dominant allele’s phenotype for a certain genetic trait

Question 21

Hybrid

Answer 21

The offspring resulting from combining the qualities of two organisms of different genetic information through sexual reproduction

Question 22

Pedigree

Answer 22

A pedigree is a chart or diagram that shows relationships between family members and indicates which individuals have certain genetic pathogenic variants, traits, and diseases within a family

Question 23

Autosomal

Answer 23

A numbered chromosome that is not a sex chromosome

Question 24

Sex linked

Answer 24

Characteristics or traits that are influenced by genes carried in the sex chromosomes