3. Reproduction And Inheritance

Question 1

Sexual reproduction

Answer 1

• genetically varies offspring
• two parent cells involved
• fertilisation
• gamete’s produced via meiosis, followed by mitosis

Question 2

Asexual reproduction

Answer 2

• genetically identical offspring
• one parent cell involved
• no fertilisation
• cell division by mitosis

Question 3

Similarity of sexual and asexual reproduction

Answer 3

Both create new individuals

Question 4

Alleles

Answer 4

An alternative form of a gene

Question 5

Dominant

Answer 5

Allele of gene that is expressed

Question 6

Recessive

Answer 6

Allele not expressed in phenotype when dominate allele is present

Question 7

Homozygous

Answer 7

Both chromosomes have the same allele (tt and TT)

Question 8

Heterozygous

Answer 8

Both contain the one of each allele (Tt and Tt)

Question 9

Phenotype

Answer 9

The characteristic that is expressed

Question 10

Genotype

Answer 10

Combination of the alleles

Question 11

Gene

Answer 11

Section of a molecule of DNA that codes for a specific protein

Question 12

Genome

Answer 12

The entire DNA of an organism

Question 13

Co dominant

Answer 13

Both alleles are expressed in the phenotype

Question 14

Pollen

Answer 14

Gamete produced in anther which is part of the male stamen of the flower

Question 15

Ova

Answer 15

Gamete produced in ovules found in the ovary within the female carpel of the flower

Question 16

Cross-pollination

Answer 16

The transfer of pollen from the anther of one flower to the stigma of another flower

Question 17

Insect pollinated flower

Answer 17

• stamen is enclosed within flower
• stigma is enclosed within flower and sticky
• petals are large and brightly coloured
• nectaries produce sugary fluid to attract insects

Question 18

Will pollinated flower

Answer 18

• stamen exposed outside of petal
• stigma exposed outside of petal, often feathery
• petals are small and usually green
• no nectaries

Question 19

Structural adaptations of insect pollinated flowers will..

Answer 19

Attract insects to them and ensure insects push close to stamens/stigmas within the flower

Question 20

Structural adaptations of wind pollinated flowers will..

Answer 20

Make sure that their stamens and stigma are exposed to the wind, achieved by having small dull coloured petals

Question 21

How can plants reproduce asexually by natural methods and artificial methods

Answer 21

Natural method - runners (a new plant is produced where the runner twitches the ground
Artificial method - cuttings (piece of plants stem with leaves is cut from healthy plant and planted into damp composts, where it grows roots and develops into a new plant)

Question 22

Role of FSH and where it’s produced

Answer 22

Produced - pituitary gland
Matures the egg and stimulates release of oestrogen

Question 23

Role of oestrogen and where it’s produced

Answer 23

Produced in ovary
Thickens uterus lining ready for embryo to implant/secondary sexual characteristics
Peaks at ovulation at day 14
Stimulates release of LH and inhibits release of FSH

Question 24

Role of LH and where it’s produced

Answer 24

Produced in pituitary gland
Stimulates ovulation and release of egg into oviduct

Question 25

Role of progesterone and where it’s produced

Answer 25

Produced in ovary Maintains uterus lining Menstruation occurs Increases after ovulation, graph drops causing shed of uterus lining

Question 26

Cell produces when an egg is fertilised

Answer 26

Zygote

Question 27

How is the developing embryo protected by amnotic fluid

Answer 27

Maintains constant and stable environment Protection from jolts/injury and temperature change

Question 28

How is the developing embryo protected by amnotic fluid

Answer 28

Maintains constant and stable environment Protection from jolts/injury and temperature change

Question 29

How does the structure of the placenta enable efficient exchange of substances between fetus and mother

Answer 29

- blood supply maintains concentration gradient for diffusion - close distance between fetus blood and mother creates short diffusion distance - villi increases surface area for diffusion - capillary network brings nutrients to fetus and removes waste

Question 30

Role of human placenta

Answer 30

- provide fetus with oxygen from mother - provides nutrients from digested food (glucose + amino acids) - removes waste products like carbon dioxide - provides antibodies to prevent fetus from infection - produces hormones

Question 31

How do some molecules allow active transport to occur in cells of fetus

Answer 31

- glucose and oxygen provided used for respiration - ATP released in respiration is used for active transport