Patterns of Heredity & Core Vocabulary

These flashcards cover key vocabulary and concepts from the lecture on patterns of heredity and genetics, providing definitions and explanations essential for understanding the subject matter.

Gene

A segment of DNA that codes for a specific protein or trait.

Allele

Different forms of the same gene.

Phenotype

Observable physical or biochemical characteristics of an organism.

Genotype

The genetic makeup or allele combination of an organism.

Heterozygous

Having two different alleles for a specific gene.

Homozygous

Having two identical alleles for a specific gene.

Dominant allele

An allele that expresses its phenotype even when a different allele is present.

Recessive allele

An allele whose effect is masked by a dominant allele in heterozygotes.

Meiosis

The process that produces unique, haploid gametes for sexual reproduction.

Crossing over

Exchange of genetic material between homologous chromosomes during Prophase I, increasing genetic diversity.

Meiosis I

Separates homologous chromosomes.

Meiosis II

Separates sister chromatids.

Gregor Mendel

The father of genetics; he experimented with pea plants to understand inheritance patterns.

Mendel’s Principle of Segregation

During gamete formation, two alleles for a trait separate so each gamete receives only one.

Mendel’s Principle of Independent Assortment

Genes for different traits are inherited independently of each other.

Codominance

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

Incomplete Dominance

Heterozygote shows a phenotype intermediate between dominant and recessive.

ABO blood types

Inherited through multiple alleles; A and B alleles are codominant, O is recessive.

Epistasis

One gene affects the expression of another gene.

Pleiotropy

One gene influences multiple, seemingly unrelated phenotypic traits.

X-linked traits

Traits inherited through the X chromosome, usually affecting males more.

Pedigree chart

A diagram that shows the occurrence of genetic traits in several generations of a family.

X-linked dominant inheritance

Appears in every generation, affecting both males and females.

X-linked recessive inheritance

Skips generations and is more common in males.

Polygenic traits

Traits influenced by multiple genes, such as skin color or height.

Phenotype variation

Polygenic traits usually show a wide range of variation, often forming a bell curve distribution.

Missense mutation

A mutation resulting in one amino acid being replaced by another in a protein.

Nonsense mutation

A change that introduces a stop codon, terminating translation prematurely.

Frameshift mutation

Insertions or deletions that shift the reading frame of a gene.

DNA polymerase proofreading

A DNA repair mechanism that checks the accuracy of DNA replication.

DNA repair enzymes

Enzymes that fix errors in DNA to maintain genetic integrity.

Apoptosis

Programmed cell death occurring when DNA damage is too severe to repair.

Senescence

Permanent cell cycle arrest due to extensive DNA damage.

Cancer

Arises when mutations disrupt normal control of cell division.

PCR (Polymerase Chain Reaction)

A technique for amplifying specific DNA sequences.

DNA microarray

A laboratory tool used to detect the expression of thousands of genes at once.

Southern blotting

A method to detect specific DNA sequences in DNA samples.

Recombinant DNA technology

Combining DNA from different organisms to create new genetic combinations.

DNA profiling

Identifying individuals by their unique DNA patterns (e.g., forensics).

Biopharming

Using genetically modified organisms to produce pharmaceuticals.

Genetically Modified Organisms (GMOs)

Organisms whose genetic material has been altered using genetic engineering.

Stem cells

Cells with the ability to develop into many different cell types.

Cloning

Making genetically identical copies of DNA, cells, or organisms.

Hardy-Weinberg equilibrium

A principle stating allele and genotype frequencies remain constant unless disturbed by evolutionary forces.

Conditions for Hardy-Weinberg equilibrium

No mutation, random mating, no gene flow, infinite population size, no selection.

Natural selection

Increases favorable alleles and decreases unfavorable ones over generations.

Genetic drift

Random changes in allele frequencies in small populations.

Founder effect

Reduced genetic diversity when a population is descended from a small number of colonizing ancestors.

Speciation

Formation of new and distinct species in the course of evolution.