Download Biology 3201 - Chapter 14 Terms

Biology 3201 - Chapter 14 Terms
Cell Cycle – Cells reproduce through the continuous sequence of growth and division.
Interphase – The growth stage of the cell cycle. The cell makes new molecules, which
increases the cell’s volume and mass. DNA is copied during interphase. The three parts
of interphase are G1, S phase, and G2.
G1 (Gap 1) – Growth and development stage of interphase. Cells carry out metabolic
activities to prepare for cellular division.
S Phase – DNA replicates during this stage of interphase.
G2 (Gap 2) – Cells prepare to undergo cellular division. Centriole ducplicates.
Mitosis – Division of the nucleus. The daughter cells receive the exact number of
chromosomes and genetic make-up as the parent cell.
Cytokinesis – Division of the cytoplasm, forming two new daughter cells.
Chromatin – Long fibres that form chromosomes and contain DNA, RNA, and various
proteins.
Parent Cell – The original cell (before division).
Daughter Cells – The two new cells produced from the division on a parent cell.
Prophase – The first stage of the four stages of mitosis. Chromosomes condense and
can be seen as two chromatids.
Chromosome – (46 in humans) Chromatin (fibres) condensed.
Sister Chromatids – (Same genes, same alleles) Two structures in a chromosome
that are genetically identical, which are held together by a centromere.
Centromere – The point at which two sister chromatids join and which the spindle
fibres are attached during mitosis.
Metaphase – The second phase of mitosis. The chromosomes line up at the cell’s
equator in preparation for separation.
Anaphase – The third phase of mitosis. The centromere splits apart and chromosomes
move to the poles of the spindle.
Telophase – The fourth and final stage of mitosis. Daughter cell nuclei form around
chromosomes at opposite ends of the dividing parent.
Mutation – A permanent change in the DNA molecule that can change the genetic
information of a gene, causing the gene to function improperly or not at all.
Oncogenes – Genes, that when mutated, can cause cancer.
Radiation Therapy – Directs radiation, such as X-rays or gamma rays, at the infected
part of the body. Radiation damages the chromosomes in a cell, rendering it unable to
grow or divide.
Chemotherapy – A course of one or several types of drugs, depending on the patient
and the cancer. Chemotherapy affects the entire body. It attacks dividing cells as they
divide or prevents cells from dividing.
Meiosis – A cell division that only occurs in reproductive organs, producing
reproductive cells called gametes.
Gamete – The reproductive cells (sperm and egg).
Haploid (n) – Cells that contain only one copy of each type of chromosome (half).
Diploid (2n) – Cells that contain two copies of every chromosome.
Reduction Division – The first part of meiosis that reduces the chromosome number
from diploid to haploid.
Autosomes – (44 in humans) Chromosomes that are not directly involved in
determining the sex of an individual.
Sex Chromosomes – (2 in humans) Either an X or Y chromosome that carries the
genes involved in determining the sex of an individual.
Germ Cells – Sex cells.
Homologous Chromosomes (Homologs) – (Same genes, different alleles)
Chromosomes that contain the same gene sequences, but may not be made up of the
same alleles.
Tetrad – A homologous pair formed during prophase of meiosis containing four
chromatids.
Allele – Alternate form of a gene.
Crossing Over – In cellular reproduction, the process in which non-sister chromatids
exchange genes during prophase 1 of meiosis allowing for the recombination of genes.
Non-sister Chromatids – In a tetrad, chromatids that do not belong to the same
chromosome and undergo crossing over during prophase 1 of meiosis.
Gametogenesis – Gamete formation when daughter cells, or gametes, are produced
at the end of meiosis 2, resulting in the production of sperm and eggs.
Spermatogenesis – The process of male gamete production.
Spermatogonium – The diploid germ cell from which sperm are produced in the
testes.
Oogenesis – The process of female gamete production.
Oogonium – The diploid germ cell from which eggs are produced in the ovaries.
Zygote – The first cell created from 2 haploids (sperm and eggs) joining together.