Biol 315: Genetics Module 1-ch 1 & 2

Vocabulary flashcards covering key genetics concepts from Modules 1 Part A & B (Chapters 2-3).

Haploid

A cell with a single complete set of chromosomes (n); ex. gametes in humans

Diploid

A cell with two complete sets of chromosomes (2n); typical body cells

Ploidy

The number of complete chromosome sets in a cell (e.g., haploid, diploid).

Phenotype

The observable traits of an organism, resulting from the genotype and environment.

Genotype

The genetic makeup of an organism; the specific alleles present at one or more loci.

Allele

A variant form of a gene at a particular genetic locus.

Homozygous

Having two identical alleles for a given gene (e.g., AA or aa).

Heterozygous

Having two different alleles for a given gene (e.g., Aa).

Dominance

The allele whose phenotype is expressed in a heterozygote (often masks the other allele).

Recessiveness

An allele whose phenotype is expressed only when homozygous recessive and is masked in the presence of a dominant allele.

Monohybrid cross

A genetic cross examining a single trait.

Dihybrid cross

A genetic cross examining two different traits.

Selfing

Self-fertilization; an organism fertilizes itself to produce offspring.

Testcross

Crossing an unknown genotype with a homozygous recessive to infer the unknown's genotype.

Meiosis

Cell division that halves the chromosome number to form gametes.

Segregation

The separation of paired alleles into gametes during meiosis.

Fertilization

The union of sperm and egg to form a zygote.

Sister chromatid

Two identical copies of a replicated chromosome held together at the centromere.

Homologous chromosomes

A paternal and a maternal chromosome that carry the same genes in the same order.

Bivalent

A paired set of homologous chromosomes (tetrad) aligned during meiosis I.

Non-sister chromatid

Chromatids from different homologous chromosomes that can undergo crossing over.

Independent assortment

The random distribution of different gene alleles into gametes, contributing to genetic variation.

X-linked

Genes located on the X chromosome; inheritance patterns differ between males and females.

Autosomal

Genes located on non-sex (autosome) chromosomes.

Pedigree

A diagram of family relationships used to study inheritance patterns.

Gene

A specific DNA sequence that codes for a protein or functional product.

Chromosome

A structure that contains DNA and proteins; they are replicated and segregated during cell division.

DNA

the molecule that stores genetic information.

mRNA

RNA transcript that carries genetic information from DNA to the ribosome for protein synthesis.

Protein

A molecule that performs a wide range of cellular functions; the product translated from mRNA.

Central dogma

DNA is transcribed into RNA, which is translated into protein.

Zygote

The diploid cell formed when a sperm fertilizes an egg.

Interphase

Phase of the cell cycle when the cell grows and DNA is replicated before division.

Dihybrid cross

Cross of 2 identical heterozygotes. Ex. A/a X A/a