Vocabulary Flashcards
Chromosome
A threadlike structure made of protein and a single molecule of DNA that serve to carry the genomic information from cell to cell.
Homologous
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)
Diploid
The presence of two complete sets of chromosomes in an organism’s cells, with each parent contributing a chromosome to each pair
Haploid
A cell that contains a single set of chromosomes
Ova
Unfertilised female gamete
Sperm
Male gamete
Fertilisation
- Union of two gametes
- Sperm and egg fuse to form a diploid zygote to initiate prenatal development
Zygote
The fertilized egg cell that results from the union of a female gamete with a male gamete
Mutations
- 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
Gene
A stored set of instructions for a protein, found on a specific locus (position) on a chromosome
Allele
- 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
Karyotype
An individual’s complete set of chromosomes
Locus
The physical site or location of a specific gene on a chromosome
Homozygous
- Possessing two identical alleles of a gene
□ AA is a homozygous dominant genotype
□ aa is a homozygous recessive genotype
Heterozygous
Possessing two different alleles of a gene
Genotype
- 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
Phenotype
- An individual’s observable traits, such as height, eye colour, etc
- Determined by genetic makeup and environmental factors
Dominant
- 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
Recessive
- 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
Monohybrid cross
A hybrid of two individuals with homozygous genotypes which result in the dominant allele’s phenotype for a certain genetic trait
Hybrid
The offspring resulting from combining the qualities of two organisms of different genetic information through sexual reproduction
Pedigree
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
Autosomal
A numbered chromosome that is not a sex chromosome
Sex linked
Characteristics or traits that are influenced by genes carried in the sex chromosomes
