Chromosome pairs fail to separate properly . Results in a imbalanced
amount of chromosomes
What is a CHROMOSOME ?
In eukaryotic cells , the DNA is coiled into very compact structures which are called chromosomes.
What is a HISTONE ?
The proteins that DNA wraps tightly around. Histones help maintain the shape of the chromosome and aid in the tight packing of DNA.
What is a CHROMATID ?
Each half of the chromosome is a Chromatid. They form as the DNA makes a copy of itself before cell division.
What is a CENTROMERE ?
The point where the two chromatids of a chromosome are attached. It holds the two chromatids together untill they separate during cell division.
What is a CHROMATIN ?
The less tightly Coiled DNA- Protien complex is called Chromatin.
What is a SEX CHROMOSOME ?
Chromosomes that determine the sex of an organism, they may also carry genes for other characteristics.
What is are AUTOSOMES ?
All of the otherchromosomes in an organism. Two of the 46 human chromosomes are sex chromosomes and the remaining 44 chromosomes are autosomes.
What are HOMOLOGOUS CHROMOSOMES?
Two copies of each autosome. They are the same shape and size and carry genes for the same traits.
What is a KARYOTYPE ?
A photomicrograph of the chromosomes in a normal dividing cell found in a human.
What is a DIPLOID ?
Cells having two sets of chromosomes.
What is a HAPLOID ?
Sperm and egg cells are haploid cells , they only contain one set of chromosomes.
What is BINARY FISSION ?
The division of prokaryotic cell into two offspring cells Where the DNA is copied resulting in two identical chromosomes attached to the inside of the prokaryote's inner cell membrane. A new cell membrane then begins to develope between the two DNA copies. The cell grows until it reaches approcimatly twice the cell's original size As the new material is added , the growing cell membrane pushes inward and the cell is constricted in the center, like a balloon being squeezed in the middle. A new cell wall forms around the new membrane. Eventually the dividing prokaryote is split into two independent cells. Each cell contains one of the identical chromosomes that resulted from copying of the original cell's chromosome. Creates two identical haploid cells.
What is MITOSIS ?
Cell division that results in new cells with genetic material that is identical to the genetic material of the orignial cell. Occurs in Organisms undergoing growth, development , repair , or asexual reporduction.
What is ASEXUAL REPRODUCTION ?
The production of offspring from one parent. There are three types of asexual reproduction , Budding , Fragmentation , and Regeneration.
What is Meiosis ?
Occurs during the formation of gametes, Meiosis reduces the chromosome number by half in new cells. Each new cell has the potential to join with another haploid cell to produce a diploid cell with a complete set of chromosomes.
What are GAMETES ?
Haploid reproductive cells
What is CYTOKINESIS ?
the division of the cell's cytoplasm .
What is PROPHASE , and what occurs in this phase?
The first phase of mitosis, begins with the shortening and tight coiling of DNA into rod shaped chromosomes that can be seen with a light microscope.