DNA, Chromosones & cell division

Question 1

DNA=

Answer 1

DeoxyriboNucleic Acid

Question 2

gene

Answer 2

section of DNA that codes for protein

Question 3

the four bases

Answer 3

adenine (a)
thymine (t)
guanine (g)
cytosine (c)

Question 4

complementary base

Answer 4

pairs are bases that match each other ie a+t and c+g

Question 5

base pair rule

Answer 5

bases can occur in any sequence along the strand of DNA but they must be complementary

Question 6

chromosones

Answer 6

structure found inside a nucleus of a cell

Question 7

how many pairs are there

Answer 7

23 pairs, 46 in total

Question 8

diploid cell

Answer 8

has two copies of each chromosomes (occurs in pairs)

Question 9

haploid cell

Answer 9

one copy of each chromosomes

Question 10

mitosis

Answer 10

nucleus divides into two identical nuclei that have the same number of chromosomes

Question 11

functions of mitosis in multi-cellular organisams

Answer 11

allows for growth
replacement
and for repairs

Question 12

functions in singular celled organisms

Answer 12

asexual reproduction ie. yeast(fungus)

Question 13

cancer

Answer 13

develops when cells lose the ability to control the rate of mitosis

Question 14

mutations

Answer 14

are changes in amount or structure of DNA

Question 15

factors that increase the risk of cancer

Answer 15

^age
^hereditary (family history)
^carcinogens
-cigarette smoke
-ultra-violet radiation
- certain viral infections
-asbestos

Question 16

benign tumors

Answer 16

non-canercous. they grow slowly and are only life-threatening if it presses against a vital organ

Question 17

malignant tumors

Answer 17

cancerous. grow quickly and spread to other organs

Question 18

how can malignant tumors be treated

Answer 18

through surgery, chemotherapy and radiotherapy

Question 19

meiosis

Answer 19

(diploid cells turned into haploid cells) cells divide into 4 new cells that contain half the number of chromosomes

Question 20

functions of meiosis

Answer 20

-produce gametes for sexual reproduction
-variation; offspring is different to parents and siblings

Question 21

where does meiosis happen

Answer 21

animals - sex organs
plants - takes place within anthers and overies

Question 22

difference between mitosis and meiosis

Answer 22

meiosis:
- 1 cell into 2
-new cells are identical to each other
- same # of chromosomes
mitosis:
-1 cell into 4
-not identical
-# of chromosomes is halved