Chromosomes Flashcards
Chromosomes are made of two…
identical structures joined together called chromatids.
During interphase, each…
DNA molecule in a nucleus makes an identical copy of itself.
Each chromatid contains…
one of the copies of DNA produced during interphase.
The two chromatids are held together by…
a narrow region called centromere, forming a chromosome.
The position of the centromere is…
charcteristic for particular chromosome.
Each chromatid contains one…
DNA molecule, which is identical to the other DNA in the second chromatid.
DNA is a molecule of…
inheritance and is made up of a series of genes.
When cell divide one chromatid goes…
into one daughter cell and the other to second daughter cell, making them genetically identical.
Chromatin is…
the combination of DNA and proteins. The DNA is wound around the outside of these proteins.
Chromosomes are made of…
chromatin.
Most of the proteins are…
basic so they easily interact with DNA which is acidic.
Nucleosome is…
the basic unit of a structure of chromatin.
Nucleosome has a cylindrical…
shape, about 11nm wide and 6nm long.
A nucleosome is made up of…
8 histone molecules.
The DNA is wrapped…
around the outside of the cylinder(nucleosome) and it is held in place by histone molecules.
The chromosomes seen just before nuclear division represent…
the most tightly coiled(condensed) form of DNA.
The nucleosome line up like a string of…
beads. This string can be further coiled and supercoiled.
The extent of coiling of chromatin varies…
during the cell cycle.
Karyotype is a diagram…
showing all pairs of chromosomes.
Diploid cells (2n)
- two sets of chromosomes
- somatic cells-forming the organism
Haploid cells (n)
- only one set of chromosomes
- gametes
- produced by reduction division
First 22 pairs of chromosomes are…
autosomes-not a sex chromosome
23rd pair is…
gonosome (sex chromosomes)
Homologous pairs are similar in…
structure and composition.
Each member in homologous pairs comes from…
one of the parents.
Each homologous pair posses…
alleles of the same gene.
A change in allele is called…
mutation.
A gene is…
length of DNA coding for a specific sequence of amino acids. (polypeptide chain)
