Genetics Review

These flashcards cover key concepts related to genetics, including definitions, laws, and processes related to inheritance.

What is genetics?

The study of passing on traits from parents to offspring.

Mendel’s Law of Dominance

A dominant allele can cover up or mask a recessive allele.

Law of Segregation

Each individual carries 2 alleles for each trait.

Law of Independent Assortment

Genes for different traits are inherited independently of each other.

Probability

Likelihood something will occur, expressed as a percentage.

Ratio

A comparison between two or more values.

Homozygous

Having the same alleles for a particular gene.

Heterozygous

Having different alleles for a particular gene.

Alleles

Different forms of a gene.

Punnett Square representation of alleles

Dominant alleles are written with a capital letter, and recessive alleles are represented with a lowercase letter.

Heterozygous genotype with B

Bb

Homozygous dominant genotype with B

BB

Homozygous recessive genotype with B

bb

Purpose of meiosis

The process of cell division in gametes resulting in four daughter cells each with half the number of chromosomes.

Diploid cells

Cells that contain two complete sets of chromosomes.

Haploid cells

Cells that contain one complete set of chromosomes.

Chromosomal number disorders

Disorders caused by a wrong number of chromosomes.

Chromosomal structural disorders

Disorders caused by damaged or rearranged chromosomes.

Karyotype

The appearance and number of an organism’s chromosomes used to identify chromosomal disorders.

Difference between mitosis and meiosis

Mitosis produces 2 identical diploid cells, while meiosis produces 4 non-identical haploid cells.

Phases of meiosis

Prophase 1, Metaphase 1, Anaphase 1, Telophase 1, Prophase 2, Metaphase 2, Anaphase 2, Telophase 2.

When does crossing over occur?

During Prophase 1.

When are homologous chromosome pairs separated?

During Anaphase 1.

When are sister chromatids pulled apart?

During Anaphase 2.

Genotypes for yellow and green pea cross

Yy x yy.

Phenotype Ratio of Yellow to Green Peas

2:2 or 1:1 ratio.

Probability of Brown eyes and no widow's peak

25%.