Bio 134 Cell Division and Genetics Vocabulary Flashcards

Vocabulary flashcards generated from Bio 134 lecture notes on cell cycle, mitosis, meiosis, and genetics.

Cell cycle

The life of a cell, from when it was first formed, up until cell division.

Genome

All of a cell's DNA.

Chromosome

A structured piece of DNA; eukaryotic cells usually have multiple linear chromosomes, while prokaryotic cells usually have one circular chromosome.

Chromatin

A condensed complex of DNA and proteins formed by winding a chromosome around proteins called histones.

Somatic cells

Nonreproductive cells in a multicellular eukaryotic organism that have two copies of each chromosome ($2 \times 23 = 46$ in humans).

Gametes

Reproductive cells (also called germ cells) in a multicellular eukaryotic organism that have one copy of each chromosome ($1 \times 23 = 23$ in humans).

Histones

Proteins around which a chromosome is wound to form chromatin.

Mitosis

The process of dividing the genetic material in the nucleus into two identical sets.

Sister chromatids

Two duplicated pieces of a chromosome that remain attached to each other.

Centromere

The region where two sister chromatids are attached to each other.

Centrosome

A microtubule organizing center (MTOC) in animal cells out of which microtubules grow.

Centrioles

Small microtubule structures located in the centrosome that are important in cell division.

Mitotic spindle

A structure made of microtubules and other proteins that forms in the cytoplasm at the beginning of mitosis to separate chromosomes.

Kinetochore

A protein complex on the centromere of chromosomes where microtubules attach.

Cytokinesis

The division of cytoplasm and cytoplasmic components, pinching the cell into two separate cells.

Checkpoint

A control point in the cell cycle where stop or go signals can regulate progression.

Kinases

Protein enzymes that can add a phosphate group to other proteins, generally turning that protein's function ON.

Proto-oncogenes

Genes that encode for positive cell-cycle regulators that make the cell cycle proceed forward.

Oncogenes

Mutated proto-oncogenes that inappropriately drive the cell cycle forward and lead to tumor formation.

Tumor suppressor genes

Genes that encode for negative cell-cycle regulators that stop the cell cycle at checkpoints.

p53

A tumor suppressor gene called the 'guardian of the genome' that turns ON expression of genes that inhibit the cell cycle.

Genetics

The study of heredity and inherited variations.

Heredity

The transmission of traits from one generation to the next.

Variation

Differences between members of the same species.

Gene

A discrete unit of hereditary information consisting of a specific nucleotide sequence.

Locus

A gene's specific location on a chromosome.

Diploid

A cell that contains two complete sets of chromosomes ($2n$), one from each parent.

Haploid

A cell that contains only one set of chromosomes ($n$).

Karyotype

A display of chromosome pairs in the cell arranged by size and shape.

Homologous chromosomes

A pair of chromosomes of the same length that possess genes for the same character traits at the same loci.

Sex chromosomes

X and Y chromosomes that determine the sex of the individual.

Autosomes

Non-sex chromosomes.

Fertilization

The union of two haploid gametes ($n$) to form a diploid zygote ($2n$).

Zygote

A fertilized egg produced by the union of two haploid gametes.

Meiosis

A cell division process consisting of Meiosis I and Meiosis II that produces haploid gametes from a diploid cell.

Synaptonemal complex

A large protein complex formed during prophase I that physically attaches homologous chromosomes to each other.

Chiasmata

The spots where genetic crossovers occurred, holding homologous chromosomes together after the synaptonemal complex disassembles.

Crossing over

A process occurring during prophase I of meiosis where broken DNA backbones reattach between homologous chromosomes to produce genetic diversity.

Independent assortment

The random distribution of maternal and paternal chromosomes into gametes during meiosis.