Mitosis and Meiosis

Question 1

What stage the of the cell cycle does cell division occur

Answer 1

M

Question 2

What is G0

Answer 2

So not dividing. With signal can re-enter cell cycle e.g. liver cells neuron introduce era and never re-enter cell cycle

Question 3

What are Telomeres

Answer 3

Repeated sequence TTA GGG non-coding DNA protects the chromsomes

Question 4

Chromosome structure

Answer 4

Metacentric
sub metacentric
acrocentric
telocentric

Question 5

Mitosis

Answer 5

Subdivision of somatic cells
production of two identical daughter cells
50 mitotic rounds during development
mitotic growth necessary for some tissues such as spermatogonia

Question 6

Pro phase

Answer 6

Nuclear membrane begins to break away
chromosome condense
Centrioles migrate to different poles
nucleus disappears

Question 7

Pro metaphase

Answer 7

Nucleus membrane disappears
kinetochore attached to the centromere
spindle fibres from centrioles attached to kinetochore’s

Question 8

Anaphase

Answer 8

Spindle fibres pull on sister chromatides
centromere divides
sister chromatid migrate to opposite poles

Question 9

telophase

Answer 9

Nuclear membrane reforms
Cchromosomes de condense
spindle fibres disappear
nucleolus reappears

Question 10

cyto kinesis

Answer 10

Cytoplasm divides

Question 11

Meiosis

Answer 11

Special subdivision for germline cells
production of four nonidentical cells
one round of replication followed by two rounds of division meiosisi 1 and 2
diploid reduced haploid
production of egg and sperm

Question 12

Pro phase 1

Answer 12

Nuclear membrane begins breakaway
chromosomes condense
centrioles migrate to different poles of cell
homologous pairs of chromoomes begin to find each other
homologous pairs lineup in twos
crossing over occurs between alleles of parental and maternal

Question 13

Meta phase 1

Answer 13

Pairs of homologous chromosomes line up randomly
spindle fibres attached to kinetochore is attached to centromere
as variation as paternal and maternal Crimson’s line up randomly in twos

Question 14

anaphase 1

Answer 14

Pair of cchromosomes separate
microtubules pull on homologous chromosomes
centromere and not divided

Question 15

telophase 1

Answer 15

Nuclear membrane formed is
chromosome D condenses
spindle fibres disappear

Question 16

meiosis II

Answer 16

Similar to mitosis

Question 17

meiosis I vs meiosis II

Answer 17

Homologous pairs of chromosomes lineup separatel

Chromosomes lineup and chromatides separate

Question 18

Consequences of meiosis

Answer 18

Maintaining constant chromosome number from generation to generation

Generation of genetic diversity
one- random assortment of chromosomes line up on metaphase plate randomly Metaphase I
two- crossing over of genetic material prophase I

Question 19

Length of OOGenesis

Answer 19

12 to 15 years

Question 20

Meiosis in making egg

Answer 20

Make three polar bodies, one big egg

Question 21

What happens when meiosis goes wrong

Answer 21

. Third of all identified miscarriages
. Infertility
. The leading cause of mental retardation

Question 22

Non-disjunction

Answer 22

Leads to aneuploidy, leads to mosaicism presence of two more signs in individual

Question 23

Non-dysjuntion first pre-zygotic division

Answer 23

Non-mosaic karyotype

Question 24

Non-disjunction later mitotic divisions

Answer 24

Mosaic karyotype