What Is The Genetic Makeup Of Meiosis

MEIOSIS

The notation for the number of chromosomes has changed. Instead of "Due north", we are now using "C" . "N" would be appropriate when talking almost ploidy, as in haploid, diploid and tetraploid, merely "C" is more appropriate when talking about changes during a cell cycle.

Have HOME MESSAGE: [see shut-upward]

In MEIOSIS I, each girl prison cell gets EITHER the maternal OR the paternal PAIR of chromosomes.
[NOTE: each chromosome is carve up. There will virtually always be a mix of chromosomes from the mother and begetter in the entire cell. That is, non ALL the maternal chromosomes will stop up on one cell.]

In MITOSIS, each girl cell gets Ane maternal chromosome and 1 paternal chromosome.

The post-obit is to be used along with the MEIOSIS overhead. Come across besides the two animations Meiosis I and Meiosis II

CHROMOSOME TABLE

MITOSIS[#/cell]:

	BIG RED	Large Blueish	little red	little blue	C
A	2	2	2	ii	4
B	two	ii	two	2	4
C	i/1	1/1	1/1	1/1	2

MEIOSIS[#/cell]:

	Large Ruby-red	BIG Bluish	trivial reddish	little blue	C
A	2	2	2	2	4
B	2	two	ii	2	4
C	two/0	0/2	0/2	2/0	2
D		2	2		2
Eastward		2	2		2
F		1/1	1/one		1

In the Meiosis Ii animation the "F" line above refers to the right hand pair of cells at the cease of the animation.

EXPLANATION:

A	Starts at metaphase. The chromosomes take already duplicated, from 2C to 4C and the cell is ready to divide. There are two chromosomes BIG and little. In that location are two sets, one originally from the mother [red], 1 from the begetter[blue].
B	This stage shows the deviation between meiosis and mitosis. In Meiosis the duplicated chromosomes do non split from each other [mitosis], only either a maternal OR a paternal set goes to each pole.
C	Cell division is complete. Both mitosis and meiosis are 2C at this phase. BUT, the genetic makeup of the two girl cells in mitosis is identical, whereas in meiosis the genetic makeup is Not identical [daughter cells are lacking either a maternal or paternal chromosome for each chromosome pair].
D	Now the chromosomes line upwards every bit in mitosis, simply there is only one pair of chromosomes for each chromosome, non 2C as in normal mitosis.
E	Chromosomes dissever.
F	Daughter cells are at present 1N [haploid], each with a mix of maternal and paternal chromosomes, merely have a complete 1N set of all the chromosomes. [Normal cells take a 2N set, diploid]

CROSSOVER

Meiosis explains how in sexual reproduction, traits that are on two different chromosomes in parents tin come up to exist recombined in an offspring. [You accept your begetter's nose and your mother'due south hair.]. Crossover explains how traits on the same chromosome, but coming from different parents tin be recombined. In that location is a limit hither as to how "flexible" a chromosome is and traits that are closer to each other or closer to the kineticore [blackness ball on effigy below] on a chromosome are less likely to be exchanged. Crossover occurs at Phase Meiosis A every bit seen in the graphic overhead. This is when the maternal and paternal chromosomes are in close proximity to each other.

Taken together, meiosis and crossover, the possibilities of recombining of genetic data are immense. This gives sexual reproduction a significant advantage over asexual reproduction.

See the lesson MIXING THE GENE Pool. And information in MITOSIS & CENTROSOMES

Source: https://web.stanford.edu/group/Urchin/meiosis.htm

Posted by: ruckersoetted.blogspot.com

Share this post