CELL DIVISION AND CELL REPLICATION

Question 1

What happens in G1 phase during cell divions

Answer 1

cell increases in size and new biomass is made

Question 2

what happens during G2 of cell cycle

Answer 2

cells get ready for divisons

Question 3

gene definition

Answer 3

section of DNA that codes for sequence of amino acids in a protein

Question 4

allele definition

Answer 4

different versions of same gene

Question 5

chromosome definition

Answer 5

dependent DNA molecule in a condensed from which contains many genes

Question 6

sister chromatids definition

Answer 6

genetically identical copies. Chromosome joined together by a single centromere

Question 7

haploid definition

Answer 7

one copy of each chromosomes

Question 8

diploid definition

Answer 8

2 copies of each chromosomes

Question 9

binary fission

Answer 9

1. replication of DNA and of plasmids
2. division of the cytoplasm to produce 2 daughter cells with a single copy of circular DNA
3. cell elongates from the middle , separating 2 DNA molecules
4. a cell wall formed down the middle of the elongated cell

Question 10

HCL

Answer 10

break down cell wall

Question 11

meiosis

Answer 11

homologous chromosomes associates (bivalent formed)
chiasmata formed
equal length of chromatids
produces new combination of alleles

Question 12

importance of mitosis

Answer 12

1. repair of damaged tissues
2. replacement of dead cells
3. increasing cell numbers and growth of organisms

Question 13

prophase

Answer 13

1. nuclear membrane break down
2. centrioles move to the poles and make spindle fibers
3. chromosomes supercoil and condense and become visible
4. Each chromosomes appear as 2 identical sister chromatids joined at the centromeres

Question 14

anaphase

Answer 14

1. spindle fibers contract
2. centromere splits
3. identical sister chromatids are pulled to opposite poles
4. making a V shape

Question 15

metaphase

Answer 15

1.centrioles complete production of spindle fibers
2. chromosomes are attached to the spindle fibers by their centromere
3. chromosomes align down the equator of the cell

Question 16

telophase

Answer 16

1. nuclear membrane starts to reform around each set of chromosomes
2. chromosomes unwind and become visible

Question 17

cyctokineses

Answer 17

cell surface membrane pinches together , cytoplasm divides forming 2 daughter cells