cell division

Question 1

haploid cell

Answer 1

one pair of chromosomes eg gamete

Question 2

diploid cell

Answer 2

two pairs/sets of chromosomes eg somatic cells

Question 3

interphase

Answer 3

phase in the cell cycle when the cell is not dividing

Question 4

mitosis

Answer 4

form of nuclear division in which one nucleus divides to form two nuclei, each containing the same number of chromsomes with identical genes

Question 5

meiosis

Answer 5

form of nuclear divison in which the four daughter nuclei contain half the chromosome number of the parent nucleus

Question 6

prophase

Answer 6

-chromatin start to contract
-chromosomes become visible as double stranded structures
held together at the centromere
- 2 strands have identical genes
- nucleolus disappears
-fibres appear in cytoplasm called spindle fibres
- nuclear membrane starts to break down

Question 7

metaphase

Answer 7

• nuclear membrane completes its breakdown
  -a spindle fibre from each pole of the cell attaches to each centromere

Question 7

telophase

Answer 7

• chromosomes at each pole begin to lengthen and become hard to distinguish
• spindle fibres break down
• nucleolus re-forms
• a nuclear membrane forms around the chromatin
• at the end of mitosis, the original nucleus has divided into 2 identical nuclei

Question 7

anaphase

Answer 7

• spindle fibres contract, causes centromere to split
• one chromosome/ strand from each double stranded chromosome is pulled to opposite poles of the cell
• the four chromosomes pulled to each pole have identical genes

Question 7

animal cells divide by ….

Answer 7

cleavage furrow

Question 8

plant cells divide by …..

Answer 8

forming a cell plate

Question 9

cancer

Answer 9

group of disorders in which certain cells test their ability to control both the rate of mitosis and the number of time mitosis takes place

Question 10

causes of cancer

Answer 10

cigarette smoke, abestos fibres, pesticides, ultra-violet radiation