Genetics and Variation - Video Notes (Vocabulary Flashcards)

Vocabulary-style flashcards covering key genetics concepts from DNA structure to meiosis, variation, and inheritance.

Zygote

Fertilized egg cell.

Fertilization

Fusion of egg and sperm cell.

Backbone of DNA

Made of phosphate and sugar (the sugar-phosphate backbone).

Base pairs

A pairs with T and G pairs with C.

Genotype

A combination of two alleles inherited from parents.

Phenotype

A physical appearance.

Alleles

Variations of the same gene.

Haploid

Having half the number of chromosomes; gametes are haploid.

Mitosis

A type of cell division that is responsible for growth.

Chromosome

Long threads of DNA found in the nucleus.

Meiosis

A process that leads to genetic variation via two processes: independent assortment and crossing over.

Independent assortment

During meiosis, homologous chromosome pairs line up randomly, so the combination of alleles in gametes is random.

Crossing over

Homologous chromosomes swap sections of genetic material, creating new allele combinations.

Continuous variation

Variation typically measured on a continuum (e.g., height).

Discontinuous variation

Variation that falls into distinct groups (e.g., eye color categories).

Recessive allele

Lowercase allele; masked by a dominant allele and affects phenotype only when inherited from both parents.

Dominant allele

Capital letter allele; can determine phenotype even if present only once.

Homozygous

Having the same two alleles.

Homozygous Dominant (HH)

Two dominant alleles for a trait.

Homozygous recessive (hh)

Two recessive alleles for a trait.

Heterozygous (Hh)

Having different alleles for a trait.

Genetic variation

The presence of genetic differences between individuals.

Random fertilization

A random sperm fertilizes an egg during conception.