BIOL 1406 Study Guide - Exam 4

Vocabulary flashcards created from lecture notes for exam preparation in biology.

Cell Cycle

The series of phases including G1 (growth), S (DNA synthesis), G2 (prep), M (mitosis), and G0 (resting/non-dividing).

Checkpoints

Control points in the cell cycle including G1, G2, and M checkpoints.

G0 phase

A resting phase where nerve/muscle cells are permanent, and temporary for other types.

Mitosis

A process for growth, repair, and asexual reproduction consisting of phases: Prophase, Prometaphase, Metaphase, Anaphase, Telophase.

Cytokinesis

The process that divides the cytoplasm after mitosis.

Apoptosis

Programmed cell death that balances mitosis for tissue homeostasis.

Caspases

Key enzymes involved in the process of apoptosis.

DNA Packaging

The wrapping of DNA around histone proteins forming nucleosomes.

Euchromatin

Active form of DNA, less compact.

Heterochromatin

Inactive form of DNA, more compact.

Chromosomes

Structures made of DNA and proteins, replicated during S phase.

Sister chromatids

Identical copies of a chromosome, joined by a centromere.

Meiosis

Type of cellular division that results in four haploid gametes from one diploid cell.

Homologous chromosomes

Pairs of chromosomes containing the same genes but may have different alleles.

Crossing-over

Exchange of genetic material between homologous chromosomes during Prophase I of meiosis.

Independent assortment

The random distribution of homologous chromosomes during Metaphase I of meiosis.

Random fertilization

The process by which any sperm can fertilize any egg, contributing to genetic variation.

Spermatogenesis

The process resulting in four functional sperm from one diploid cell.

Oogenesis

The process resulting in one egg and two to three polar bodies from one diploid cell.

Aneuploidy

An abnormal number of chromosomes, such as in trisomy.

Mendel's Law of Segregation

The law stating that alleles separate during gamete formation.

Mendel's Law of Independent Assortment

The law stating that genes on different chromosomes assort independently.

Monohybrid inheritance

A genetic cross involving one trait, producing a 3:1 phenotypic ratio.

Dihybrid inheritance

A genetic cross involving two traits, producing a 9:3:3:1 phenotypic ratio.

Testcross

A method used to determine the genotype of an unknown individual by crossing with a homozygous recessive.

Incomplete dominance

A form of inheritance where the phenotype is a blend of both parents' traits.

Codominance

A form of inheritance where both traits are expressed in the phenotype.

Multiple alleles

Having more than two alleles for a genetic trait, as seen in ABO blood groups.

Sex-linked traits

Traits that are associated with genes located on sex chromosomes, often X-linked.

Centromere

The region where two sister chromatids are joined together.

Gametes

Haploid reproductive cells produced during meiosis.

Phenotypic ratio

The ratio of different phenotypes in the offspring of a genetic cross.

Chromosomal mutations

Changes to the structure of chromosomes including deletion, duplication, and translocation.

Nondisjunction

Failure of homologous chromosomes or sister chromatids to separate properly during cell division.

Viable egg

One functional egg produced during oogenesis that can be fertilized.

Punnett square

A diagram used to predict the outcome of genetic crosses.

Growth phase (G1)

The phase where the cell grows and prepares for DNA synthesis.

S Phase

The phase in the cell cycle where DNA is replicated.

M phase

The phase of the cell cycle where mitosis occurs.

Repair function of mitosis

Mitosis repairs damaged tissues by producing new cells.

Genetic variation sources in meiosis

Include crossing-over and independent assortment.

Balancing mitosis

Apoptosis ensures that cell death balances cell division for tissue maintenance.

Cell cycle control

Mechanisms that regulate progression through the phases of the cell cycle.

Chromosome structure

Chromosomes composed of DNA and proteins that condense during cell division.

Mitosis phases

Prophase, Prometaphase, Metaphase, Anaphase, Telophase are the stages of mitosis.

Haploid gametes

Cells produced by meiosis with half the chromosome number of the parent.

Prophase I (Meiosis)

The stage where crossing-over occurs, increasing genetic variability.