3. reproduction and inheritance

Question 1

where is oestrogen produced?

Answer 1

in the ovary

Question 2

what is the role of oestrogen?

Answer 2

-stimulates the uterus to develop a lining (causes uterus lining to thicken)
-post ovulation, inhibits FSH and LH production

Question 3

where is progesterone produced?

Answer 3

in the ovary

Question 4

what is the role of progesterone?

Answer 4

-maintains and thickens the lining of the uterus
-inhibits FSH and LH production
-if fertilisation doesn’t occur, levels drop and menstruation occurs

Question 5

where is FSH produced?

Answer 5

pituitary gland

Question 6

what is the role of FSH

Answer 6

-causes eggs to mature in ovaries
-stimulates follicles in the ovaries to secrete oestrogen

Question 7

where is LH produced?

Answer 7

pituitary gland

Question 8

what is the role of LH?

Answer 8

-stimulates ovulation (release of egg from ovary to oviduct)

Question 9

number of parent organisms in asexual reproduction and sexual reproduction

Answer 9

A- 1, S- 2

Question 10

What type of cell division is required to produce offspring in asexual and sexual reproduction?

Answer 10

A- mitosis
S- meiosis (to produce gametes), mitosis after fertilisation

Question 11

what level of genetic similarity between offspring is in asexual and sexual reproduction?

Answer 11

A- genetically identical to each other and to the parent
S- genetically unique and different from both parents

Question 12

what sources of genetic variation in offspring is in asexual and sexual reproduction?

Answer 12

A- only one source (mutation)
S- three sources-
- contribution of 50% if their DNA from each of the 2 parents
- production of gametes by meiosis (resulting in new combinations of alleles on the chromosomes)
- random assortment of chromosomes into gametes during meiosis

Question 13

what number of offspring is usually produced and what is the time taken to produce the offspring in asexual and sexual reproduction?

Answer 13

A- relatively large numbers, fast
S- limited numbers, slow

Question 14

what is an allele

Answer 14

-variation of the same gene
-having them give rise to differences in inherited characteristics and variation within species

Question 15

what is a gene

Answer 15

a short length of DNA that codes for a specific protein

Question 16

what is a dominant allele

Answer 16

an allele that is always expressed, even if only one copy is present

Question 17

what is a recessive allele

Answer 17

can only be expressed if two copies are present (if there is no dominant allele)

Question 18

what does homozygous mean

Answer 18

two alleles of a gene that are the same- e.g. YY and yy

Question 19

what does heterozygous mean

Answer 19

two alleles of a gene that are different- e.g. Yy

Question 20

what is a genotype

Answer 20

the combination of alleles that control each characteristic

Question 21

what is a phenotype

Answer 21

the observable characteristics of an organism (seen just by looking- e.g. eye colour, or found through testing- e.g. blood type)

Question 22

what chromosomes do males and females carry

Answer 22

males = XY
females = XX

Question 23

how are petals adapted for pollination in an insect pollinated flower

Answer 23

large and brightly coloured to attract insects

Question 24

how is the scent and nectar adapted for pollination in an insect pollinated flower

Answer 24

produced to encourage insects to visit the flower and push past the stamen to get to the nectar

Question 25

how is the anthers adapted for pollination in an insect pollinated flower

Answer 25

held on stiff filaments within the flower so that they brush against the insects

Question 26

how is the stigma adapted for pollination in an insect pollinated flower

Answer 26

sticky stigmas within the flowers to catch pollen grains when insects brush past

Question 27

how are petals adapted for pollination in a wind pollinated flower

Answer 27

small and dull, often green or brown in colour

Question 28

how is scent and nectar adapted for pollination in a wind pollinated flower

Answer 28

not produced

Question 29

how is anthers adapted for pollination in a wind pollinated flower

Answer 29

held on long filaments outside the flower to release pollen grains easily into the wind

Question 30

how is the stigma adapted for pollination in a wind pollinated flower

Answer 30

feathery stigmas outside the flower catch airborne pollen grains

Question 31

how can plants reproduce asexually by natural methods

Answer 31

grow runners (side branches), which grow sideways out of the parent plant and once they touch the soil they grow roots and become independent

Question 32

how can plants reproduce by artificial methods

Answer 32

by taking cuttings (where a section of the parent plant with a new bud is cut off and then replanted)

Question 33

what is the role of the placenta

Answer 33

to enable exchange of substances between the mothers blood and that of the fetus- these include oxygen and nutrients (e.g. glucose, amino acids, and mineral ions) and take away carbon dioxide and urea

Question 34

how is the placenta adapted

Answer 34

has a large surface area and a thin wall for efficient diffusion of nutrients
contains lots of capillaries and the blood vessels are separate from the mother and fetus (don’t mix)
also contains villi

Question 35

what is amniotic fluid

Answer 35

-surrounds the developing embryo in the uterus
-contained within the amniotic membrane (also known as the amniotic sac)
-protects the embryo by cushioning it from bumps when the mother moves around