Cell Biology and Genetics Review

Comprehensive vocabulary flashcards covering the cell cycle, mitosis, meiosis, cancer biology, mutagens, sex determination mechanisms, and Mendelian inheritance patterns.

Cell Cycle Regulation

The internal molecular control system, mediated by checkpoints and regulatory proteins, that determines whether a eukaryotic cell will proceed through the stages of cell division.

Abnormal Cell Cycle Regulation

A failure of normal cell cycle controls and checkpoints that leads to unregulated, uncontrolled cell division and tumor formation or cancer.

Tongue Sole Fish (Cynoglossus semilaevis) Sex Determination

A sex-determination mechanism governed by both genetics and temperature, in which $ZZ$ individuals develop into males and $ZW$ into females at $22^\bullet\text{C}$, but exposure to $28^\bullet\text{C}$ modifies the $Z$ chromosome into a $Z^*$ chromosome.

$Z^*W$ Phenotypic Male

A genetically female tongue sole fish that develops into a fertile phenotypic male when raised at $28^\bullet\text{C}$ and can transmit the modified $Z^*$ chromosome to offspring even at $22^\bullet\text{C}$.

2:1 Male-to-Female Sex Ratio in Tongue Sole Fish

The offspring ratio observed when a normal $ZW$ female mates with a $Z^*W$ male; because at least one $Z$ or $Z^*$ chromosome is mandatory for survival, the resulting $WW$ zygote is lethal, leaving two male genotypes ($Z^*Z$, $ZZ$ or $Z^*W$) to one female genotype ($ZW$).

Fitness Cost in $ZW \times Z^*W$ Mating

A severe reduction in reproductive success for the female, characterized by a $25\%$ mortality rate among offspring due to non-viable $WW$ embryos lacking a $Z$ or $Z^*$ chromosome.

Achondroplastic Dwarfism

An autosomal dominant genetic condition causing severe malformation of the skeleton; it is lethal in homozygous individuals (causing spontaneous abortion) and viable only in heterozygotes.

Achondroplasia Parental Genotypes (Matthew and Jane)

The genotypes of unaffected Matthew ($dd$) and heterozygous affected Jane ($Dd$) in a cross evaluating the risk of skeletal malformation in their offspring.

Achondroplasia Offspring Probability

The $\frac{1}{2}$ ($50\%$) chance that an unaffected individual ($dd$) and a heterozygous individual with achondroplasia ($Dd$) produce a child with achondroplastic dwarfism.

African Violet Monohybrid Inheritance

An inheritance pattern illustrated by a self-pollinating blue-flowered plant producing $36$ blue-flowered and $14$ pink-flowered offspring, indicating the parent was heterozygous and that blue flower color is dominant over pink.

Autosomal Mode of Fly Eye-Color Inheritance

An inheritance pattern demonstrated by an $F_2$ generation consisting of $40$ red-eyed females, $13$ sepia-eyed females, $39$ red-eyed males, and $11$ sepia-eyed males; the identical approximately $3:1$ ratio across both sexes confirms the eye-color gene is autosomal, not sex-linked.

Meiosis vs. Mitosis Functional Distinction

The unique capability of meiosis to produce four genetically diverse, non-identical haploid gametes through crossing over and homologous chromosome reduction, unlike mitosis which produces two identical diploid daughter cells.

Mutagen

Any physical, biological, or chemical agent that causes permanent alterations or damage to cellular DNA.

Carcinogen

A specific type of agent that causes cancer by damaging cellular DNA and introducing mutations into critical regulatory genes.

Antioxidants

Protective molecules that help prevent cancer development by neutralizing free radicals before they can induce mutations or oxidative damage to DNA.

Chemotherapy and Radiation Therapy

The two most common clinical modalities used for treating cancer in human patients.

Genetically Modified Organisms (GMOs)

Organisms whose genetic material has been artificially altered, which scientific research has NOT linked to causing cancer.

Interphase

The longest phase of the eukaryotic cell cycle, during which the cell grows, carries out typical metabolic functions, and duplicates its DNA prior to cell division.

Tumor

An abnormal, non-functional mass of tissue resulting from unregulated cell division.

Regeneration

The replacement or regrowth of damaged, missing, or amputated body tissues, as seen when a starfish regrows a lost arm.

Gametes

Haploid reproductive sex cells, specifically sperm and egg cells, produced through meiosis and carrying $23$ chromosomes in humans.

Human Chromosome Count

The normal somatic complement of $46$ chromosomes (or $23$ homologous pairs) found in human diploid cells.

Cell Cycle Checkpoint Regulatory Proteins

Specific regulatory proteins that monitor cell readiness at cycle checkpoints and act to activate or deactivate progression into cell division.

Lymphatic System (in Metastasis)

A secondary circulatory and drainage network through which free cancer cells travel, alongside the cardiovascular system, to disperse across the body.

Malignant Tumor

An aggressively growing cancerous mass that invades adjacent tissues and sheds cells into the bloodstream or lymphatic pathways to form secondary tumors.

DNA Replication (Cell Division Pre-requisite)

The mandatory cellular process of copying all genomic DNA before a cell divides into two daughter cells.

Crossing Over

The exchange of corresponding large DNA segments between non-sister chromatids of homologous chromosomes during meiosis, creating unique genetic combinations.

Prophase Cycles in Meiosis

The $2$ distinct rounds of chromosome condensation and spindle formation occurring during meiosis (designated Prophase I and Prophase II).