Genetics - Patterns of Heredity and Biotechnology (Vocabulary Flashcards)

Vocabulary-style flashcards covering core genetics concepts, including heredity, Mendelian genetics, non-M Mendelian patterns, pedigrees, mutations, molecular biology techniques, biotechnology, and population genetics.

gene

A segment of DNA that codes for a specific trait (e.g., a gene for eye color).

allele

An alternative form of a gene (e.g., blue vs. brown allele for eye color).

phenotype

The physical appearance or trait shown by an organism (e.g., blue eyes).

genotype

The combination of alleles for a trait (e.g., BB, Bb, or bb).

heterozygous

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

homozygous

Having two identical alleles for a gene (e.g., BB or bb).

dominant allele

An allele that masks the presence of a recessive allele (e.g., B is dominant over b).

recessive allele

An allele that is masked by a dominant allele and only expressed when both alleles are recessive (e.g., bb).

meiosis

Cell division that produces four haploid gametes, each genetically unique.

mitosis

Cell division that produces two identical diploid daughter cells.

Meiosis I

Phase where homologous chromosomes separate.

Meiosis II

Phase where sister chromatids separate.

crossing over

Exchange of DNA between homologous chromosomes during Prophase I, increasing genetic variation.

independent assortment

Shuffles chromosomes to create genetic diversity in gametes.

Gregor Mendel

Father of genetics; studied inheritance in pea plants.

Principle of Segregation

Allele pairs separate during gamete formation; offspring inherit one allele from each parent.

Principle of Independent Assortment

Genes for different traits are passed independently of one another if on different chromosomes.

Punnett Square

A diagram used to predict genotype and phenotype combinations in offspring.

codominance

Both alleles are fully expressed (e.g., AB blood type).

incomplete dominance

The heterozygous phenotype is intermediate between the two homozygous phenotypes (e.g., red + white = pink).

ABO blood types

Inherited through codominance (A and B both dominant); O is recessive.

sex-linked trait

A trait carried on a sex chromosome, commonly the X chromosome.

X-linked inheritance

Males (XY) show the X allele they inherit; females (XX) require two copies for a recessive trait.

polygenic trait

A trait controlled by multiple genes, producing a spectrum of phenotypes (e.g., skin color, height).

pedigree

A chart where circles represent females and squares represent males; shaded symbols show the trait.

autosomal

Traits located on autosomes; typically affect both sexes similarly.

sex-linked in pedigree

Traits that often affect males more; can indicate X-linked inheritance.

mutation

Any change in the DNA sequence.

missense mutation

A change that results in a different amino acid in a protein.

nonsense mutation

A substitution that creates a premature stop codon, ending translation early.

frameshift mutation

Insertion or deletion that shifts the reading frame of DNA.

silent mutation

A change that does not alter the amino acid sequence of a protein.

apoptosis

Programmed cell death when DNA damage is too great to repair.

senescence

Permanent stop in cell division.

cancer (mutations)

Mutations in genes that control cell division may cause uncontrolled growth.

PCR (Polymerase Chain Reaction)

A method to amplify DNA, making millions of copies.

DNA sequencing

Determining the order of nucleotides in a DNA molecule.

DNA microarray

A tool to study expression of many genes at once.

Southern blotting

A technique used to detect a specific DNA sequence.

recombinant DNA

DNA created by combining genes from different sources.

DNA profiling

Analyzing DNA to identify individuals (used in forensics).

biopharming

Using genetically modified organisms to produce pharmaceuticals.

GMOs

Organisms whose DNA has been altered for specific purposes.

stem cells

Unspecialized cells that can become any cell type.

cloning

The process of making a genetically identical organism.

Hardy-Weinberg equation

p^2 + 2pq + q^2 = 1; predicts genotype frequencies in a non-evolving population.

p (allele frequency)

Frequency of one allele in a population.

q (allele frequency)

Frequency of the alternate allele in a population.

Hardy-Weinberg conditions

No mutation, random mating, no selection, large population size, no migration.

genetic drift

Random change in allele frequencies; strongest in small populations.

founder effect

Reduced genetic variation when a small group founds a new population.

natural selection

Traits that increase an organism's survival and reproduction become more common.

speciation

Process by which new species arise.