Lab 101 #6 Flashcards
Homologous Chromosomes
Two chromosomes of a pair have the same length, centromere position, and staining pattern.
A pair of identical chromosomes.
Centromere
The point on a chromosome by which it is attached to a spindle fiber during cell division.
The part of a chromosome that is attaches to the spindle fiber.
Chromatin
The material of which the chromosomes of organisms are composed.
It consists of protein, RNA, and DNA.
Centrosome
An organelle near the nucleus of a cell that contains the centrioles (in animal cells).
Where the spindle fibers develop in cell division.
Centrioles
A cylindrical organelle near the nucleus in animal cells.
Occurring in pairs.
Involved in the development of spindle fibers in cell division.
Asters
A star-shaped structure formed during division of the nucleus of an animal cell.
Surrounds centriole pair and centrosomes.
Sister Chromatid
Each of the two threadlike strands into which a chromosome divides longitudinally during cell division.
Individual strand of homologous chromosomes.
Each contains a double helix of DNA.
Cleavage Furrow
The first sign of cytokinesis during cell division on an animal cell.
A shallow groove in the cell surface near the metaphase plate.
Cell Plate
A plate that develops at the midpoint between the two groups of chromosomes in a dividing cell.
Plate that forms between two dividing plant cells.
Synapsis
The fusion of chromosome pairs at the start of meiosis.
When the homologous chromosomes “find their mate”.
Tetrad
A pair of homologous chromosomes.
Crossing over
The exchange of genes between homologous chromosomes.
When two chromosomes or sections of chromosomes switch places.
This process results in a mixture of parental characteristics in offspring.
Chiasma
A point at which paired chromosomes remain in contact during the first metaphase of meiosis, and at which crossing over and exchange of genetic material occur between the strands.
The point at which crossing over takes place.
Plasma Membrane
A microscopic membrane of lipids and proteins that forms the external boundary of the cytoplasm of a cell.
Membrane made up of lipids and proteins that surrounds the cell.
Nuclear Envelope
The double lipid bilayer membrane which surrounds the genetic material and nucleolus.
Made up of two parts: inner and outer nuclear membrane.
