UNIT 7 - Genetics and Heredity 🧑‍🔬

homologous chromosomes

Chromosome pairs with similar genetic information.

autosomes

Chromosomes not involved in sex determination.

gametes

Reproductive cells: sperm and egg.

meiosis

Cell division producing four genetically diverse gametes.

chromatid

Identical halves of a duplicated chromosome.

genetic variation

Differences in DNA among individuals.

independent assortment

Random distribution of alleles during gamete formation.

crossing over

Exchange of genetic material between homologous chromosomes.

fertilization

Union of sperm and egg to form zygote.

trait

Characteristic determined by genes.

gene

Segment of DNA coding for a trait.

allele

Different forms of a gene.

homozygous

Having two identical alleles for a trait.

heterozygous

Having two different alleles for a trait.

genotype

Genetic makeup of an organism.

phenotype

Observable characteristics of an organism.

dominant

Allele that expresses in phenotype when present.

recessive

Allele that expresses only when homozygous.

incomplete dominance

Blending of traits in heterozygous condition.

codominance

Both alleles fully express in phenotype.

polygenic trait

Trait controlled by multiple genes.

epistasis

Interaction between genes affecting a phenotype.

Punnett square

Diagram predicting genetic cross outcomes.

monohybrid cross

Cross examining one trait inheritance.

dihybrid cross

Cross examining two traits inheritance.

sex-linked genes

Genes located on sex chromosomes.

mutation

Change in DNA sequence.

mutagen

Agent causing genetic mutation.

chromosomal mutation

Alteration in chromosome structure.

germ cells

Reproductive cells that give rise to gametes.

somatic cells

Non-reproductive cells in an organism.

genetic testing

Analyzing DNA for genetic disorders.

PCR

Technique to amplify DNA segments.

clones

Genetically identical organisms or cells.

genetic engineering

Manipulating an organism's DNA.

transgenic

Organisms containing genes from other species.

recombinant DNA

DNA formed by combining DNA from different sources.

plasmid

Small circular DNA molecule in bacteria.

facilitated adaptation

Changes aiding survival in specific environments.

gene therapy

Correcting defective genes to treat diseases.

Sex chromosomes

Chromosomes that determine the sex of an individual

Meiosis I

Homologous chromosomes separate

Meiosis II

Sister chromatids separate

Gametogenesis

Production of gametes

Genetic cross

Cross-fertilization

Testcross

Cross between an organism with an unknown genotype and an organism with a recessive phenotype