Unit 5 Heredity Vocabulary

Vocabulary flashcards for Unit 5: Heredity, covering key terms and concepts from the lecture notes.

Autosomal Chromosome

A chromosome that is not a sex chromosome.

Codominance

A form of inheritance wherein both alleles are equally expressed in the phenotype of the heterozygote.

Crossing Over

The exchange of genetic material between homologous chromosomes during mitosis 1.

Deletion

A type of mutation involving the loss of a portion of a DNA sequence.

Dihybrid

A cross that is heterozygous for two different genes.

Diploid

A cell containing two sets of chromosomes (2n).

Dominant

An allele that expresses its phenotypic effect even when heterozygous with a recessive allele.

F1 Generation

The first filial generation, which is the offspring of the P generation.

F2 Generation

The second filial generation, which is the offspring of the F1 generation.

Fertilization

The fusion of gametes to initiate the development of a zygote.

Gamete

A haploid reproductive/sex cell (sperm or egg).

Genetic Diversity

The variety of genes within a species.

Genotype

The genetic makeup of an organism.

Haploid

A cell containing one half the set of chromosomes (n).

Heredity

The transmission of traits from parents to offspring.

Heterozygous

Having two different alleles for a particular gene.

Homologous Chromosome

A pair of chromosomes coding for the same alleles, one derived from each parent.

Homozygous

Having two identical alleles for a particular gene.

Incomplete Dominance

A form of inheritance wherein the heterozygous phenotype is intermediate between the two homozygous phenotypes.

Inherit

To receive traits from parents.

Insertion

A type of mutation involving the addition of a portion of genetic material.

Karyotype

The number and visual appearance of the chromosomes in the cell nuclei of an organism or species.

Law of Independent Assortment

Mendel's law stating that genes for different traits are inherited independently of each other.

Law of Segregation

Mendel's law stating that allele pairs separate during gamete formation.

Linked Genes

Genes located close enough together on a chromosome that they tend to be inherited together.

Map Distance

The distance between genes on a chromosome, determined by recombination frequencies.

Map Units

A unit of measurement for the distance between genes on a chromosome; one map unit is equal to a 1% recombination frequency.

Maternal Inheritance

Inheritance of genes located on mitochondrial or chloroplast chromosomes, which are inherited exclusively from the mother.

Meiosis

A type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes.

Monohybrid

A cross that is determining the % of one allele. follows Mendel's gennetics

Multiple Alleles

The existence of more than two alleles for a particular gene.

Nondisjunction

The failure of homologous chromosomes or sister chromatids to separate during cell division. occurrence in mitosis 1 is worse than #2

Non-nuclear Inheritance

Inheritance of genes located outside the nucleus, such as in mitochondria or chloroplasts.

P Generation

The parental generation in a genetic cross.

Paternal

Relating to or derived from the father.

Pedigree

A diagram that shows the occurrence and appearance of phenotypes of a particular gene or organism and its ancestors from one generation to the next.

Phenotypic Plasticity

The ability of an organism to change its phenotype in response to changes in the environment.

Phenotype

The observable characteristics of an organism.

Polygenic Inheritance

The inheritance of traits that are determined by multiple genes.

Probability

The likelihood of an event occurring.

Recessive

An allele that expresses its phenotypic effect only when homozygous.

Recombination

The process of forming new allelic combinations in offspring by exchanges between genetic material (as exchange of DNA sequences between homologous chromosomes). Also called genetic recombination.

Sex-Linked Trait

A trait associated with a gene that is carried only by the male or female parent.

Sexual Reproduction

A type of reproduction involving the fusion of gametes creating a zygote..

Sister Chromatid

Two identical copies of a single chromosome that are connected by a centromere.

Somatic Cell

Any biological cell forming the body of a multicellular organism other than a gamete, germ cell, gametocyte or undifferentiated stem cell.

Test Cross

A genetic cross between a homozygous recessive individual and a corresponding suspected heterozygote to determine the genotype of the latter.

Zygote

A diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.