Chapter 11: Simple Inheritance and Meiosis

Comprehensive vocabulary flashcards covering the biological concepts of simple inheritance, meiosis, gamete production, chromosome dynamics, and cystic fibrosis genetics from Chapter 11.

Allele

Different versions of the same gene.

Cystic Fibrosis (CF)

The most common life-threatening genetic disease in the United States, caused by a single-gene mutation that leads to thick mucus clogging airways and blocking digestive enzyme pathways.

CFTR Protein

A transmembrane conductance regulator protein that functions to shuttle chloride ions across cell membranes in cells lining tissues such as the lungs.

Diploid

An organism or cell carrying two copies of every chromosome ($2n$).

Homologous Chromosomes

A pair of chromosomes that contain the same genes, with one chromosome inherited from the biological mother and the other from the biological father.

Genotype

The particular genetic makeup of an individual organism.

Phenotype

The visible, observable, or measurable features or traits of an individual.

Gamete

A specialized haploid reproductive cell, such as an egg or sperm, carrying only one copy of each chromosome.

Haploid

Cells containing only one copy of each chromosome ($n$).

Meiosis

A specialized form of cell division that reduces the chromosome number by half to produce genetically unique haploid gametes.

Zygote

The diploid cell formed by the fertilization of a haploid egg by a haploid sperm.

Meiosis I

The first division of meiosis, during which homologous chromosome pairs separate into different cells, halving the chromosome number while each chromosome retains two sister chromatids.

Meiosis II

The second division of meiosis, during which sister chromatids separate, resulting in four genetically distinct haploid daughter cells.

Recombination

The process before separating at meiosis I where paired maternal and paternal homologous chromosomes physically exchange segments of DNA.

Independent Assortment

The principle that homologous chromosome pairs align and separate randomly during meiosis I, distributing alleles of different genes independently of one another.

Recessive Allele

An allele that affects the phenotype only if an organism has two copies of it, and whose effect is hidden by a dominant allele when present.

Dominant Allele

An allele that specifies the phenotype even in the presence of a different allele for the same gene, masking a recessive allele.

Heterozygous

Having two different alleles for a given gene (e.g., $Aa$).

Homozygous

Having two identical alleles for a given gene (e.g., $AA$ or $aa$).

Punnett Square

A diagram used to predict the genotypes and phenotypes of offspring by matching all possible allele combinations from parental gametes.

Modifier Gene

A secondary gene located on another chromosome (such as TGFβ1) that influences the severity or expression of a disease caused by a primary gene mutation.

Ivacaftor (Kalydeco)

A drug designed to restore and enhance the chloride-shuttling activity of malfunctioning CFTR channel proteins in patients with specific alleles, such as the G551D allele.

ΔF508 Allele

The most common mutant CFTR allele, characterized by a three-nucleotide deletion that causes the resulting CFTR protein to be absent from the cell membrane.

Forced Expiratory Volume (FEV)

A measure of lung function representing the volume of air a person can forcibly exhale in 1 second, expressed as a percentage of total lung volume.

Huntington Disease

An inherited autosomal dominant disorder that causes progressive mental deterioration and uncontrollable movements, typically with onset during middle age.