Chapter 4 Flashcards
Terms
Anaphase I
Homologous chromosomes separate.
Anaphase II
Sister chromatids separate.
Asexual reproduction
A type of reproduction involving only one parent (genetically identical offspring.)
Asters
Clusters of microtubules radiating out from the poles in dividing cells. They are present in animal cells, but not in the cells of flowering plants and most gymnosperms.
Autosome
Any chromosome that is not a sex chromosome
Cell cycle
Cyclic series of events in the life of a dividing eukaryotic cell; consists of stages of interphase, mitosis and cytokinesis
Cell plate
The structure that forms during cytokinesis in plants, separating the two daughter
Centromere
Specialized constricted region of a chromatid; contains the kinetochore. In cells at prophase and metaphase, sister chromatids are joined in the vicinity of their centromeres.
Chiasmata
Points where homologous chromosomes exchange genetic material during meiosis. An X-shaped site in a tetrad marking the location where homologous chromatids previously underwent crossing over
Chromatid
is one half of a duplicated chromosome, which pairs with its sister chromatid during cell division seen in prophase and metaphase.
Chromatin
Uncoiled DNA found in interphase
Chromosomes
structures in the cell nucleus, composed of chromatin and containing the genes Condensed DNA seen in prophase and metaphase.
Clone
A population of cells descended by mitotic division from a single ancestral cell, or a population of genetically identical organisms asexually propagated from a single individual.
Crossing over
The breaking and rejoining of homologous (non sister) chromatids during early meiotic prophase I, resulting in an exchange of genetic material.
Cytokinesis
Stage of cell division in which the cytoplasm is divided to form two daughter cells. cells produced by mitosis
Diploid
a cell containing two copies of each chromosome (2n).
DNA
Deoxyribonucleic acid The molecule that carries genetic information in cells
DNA molecule components
A phosphate group, A deoxyribose sugar, A nitrogenous base (Adenine, Thymine, Cytosine, or Guanine)
Fertilization
Fusion of n gametes; results in the formation of a 2n zygote
Gamete
A sex cell; in plants and animals, an egg or sperm containing half the normal number of chromosomes.
Gene
A segment of DNA molecule that codes for a particular trait: found at a specific
location on a chromosome (from your parents)
Germ line cell
Cells that give rise to gametes.
Haploid
a cell containing half the usual complement of chromosomes (n).
Histone
Proteins around which DNA wraps to form nucleosomes.