Unit 7 Genes

Alleles

a variation of a gene, or a different version of a DNA sequence at a specific location on a chromosome. 

Carrier

a person who has one copy of a mutated (changed) disease-causing gene but has no symptoms or mild symptoms.

codominance

a phenomenon where both alleles of a gene are fully expressed, resulting in both traits being displayed, rather than one masking the other.

Dihybrid cross

Is a genetic cross between two individuals that are both heterozygous for two different traits

Dominant

In a little that expresses its trait, even when only one copy is present in an organism genotype

Fertilization

Process by which a sperm cell from a male merges with an egg cell from a female to form a zygote

Gene

Segment of DNA that contains the instructions for building and maintaining an organism cell and passing genetic traits to offspring

Generations p/f1/f2

Parental generation initial set of parents in a genetic cross

First Filial generation, these are the offspring of the P generation. They are usually heterozygous if the P generation was homozygous.

Second Filial generation, these are the offspring of the F1 generation where there are crossed with each other

Genetics

Branch of biology, that studies, genes, genetic variations and heredity and organisms it involves understanding how traits are passed from parent to offspring through genes.

Genotype

Genetic make up of an organism in terms of the alleles it carries

Gregor Mendel

Discovered the fundamental laws of inheritance, which are law, segregation, law of independent assortment, dominant, and recessive traits

Heredity

Processed by which traits are passed from parents to their offspring it involves the transmission of genetic information through genes, which are segments of DNA located on chromosomes

Heterozygous

refers to having two different alleles for a specific gene one dominant one recessive

Homozygous

An organism is when it has identical alleles for that gene

Incomplete dominance

Genetic inheritance were neither allele is completely dominant over the other

Law of independent assortment

The levels of two or more different genes get sorted into gamete independently of one another the alleles a gamete receives from one gene does not influence the allele receive from another gene

Law of segregation

during the formation of gametes (sperm or egg cells), each allele of a gene pair separates randomly, so that each gamete only receives one allele from each gene pair, ensuring genetic diversity in offspring

Monohybrid cross

a breeding experiment where parents differ in only one trait, or characteristic, and the focus is on the inheritance of that single trait. 

Pedigree

a family tree, an animal's ancestry, or a person's education and experience

Phenotype

the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.

Pleiotropy

the production by a single gene of two or more apparently unrelated effects.

Polygenic trait

a characteristic influenced by multiple genes, rather than a single gene, often resulting in a continuous range of variation in the phenotype, like height or skin color

Principal of dominance

in a pair of contrasting traits, one trait (the dominant trait) will mask the expression of the other (the recessive trait) in the first generation (F1). 

Recessive

a characteristic that is only expressed when an individual inherits two copies of a recessive allele.

sex-linked genes

a gene located on a sex chromosome (X or Y), resulting in inheritance and expression patterns differing between males and females

Trait

a characteristic of an organism that is passed down through its genes or determined by its environment

True breeding

an organism that consistently produces offspring with the same phenotypic traits when self-fertilized or bred with another true-breeding organism for the same trait,