mock revision 15-16

Question 1

Antibiotics

Answer 1

kill bacteria/stops them reproducing, doesn’t affect viruses (since they are not living and are just genetic material surrounded by protein coat

They can break the cell membrane, which kills the cell. And prevent them from making cell walls, so they can’t grow/reproduce

Question 2

What can we do to fight resistance of antibiotics

Answer 2

Produce new types of antibiotics (hard)

Limit consumption/ save or last effort

Keep good hygiene to avoid infections

Let body deal with less harmful bacteria- some contact is good to help develop fighting mechanisms

Question 3

sperm

Answer 3

Acrosome: secretes digestive enxymes to pass through eggs jelly coating

Flagellum: a tail for movement

Mid piece: mitrochondria which releases energy by respiration for movement

Is 0.05mm long, head is 0.004mm, can release 40 million-1.2 billion at once, can move 1.3mm per hour

Question 4

egg

Answer 4

Nucleus: mothers dna

Cytoplasm: energy store to allow zygote to survive if it gets fertalised until it implants in uterus.

Jelly coat: allows only one sperm to enter

Follicular cells/ corona radiata: nourish egg along it journey

0.1mm, cant move alone , one each month

Question 5

5 days after fertilation…..
8 weeks after……

Answer 5

the egg implants on the uterus wall and keeps dividing.
it is a fetus and has specalised cells and organs begin to form. It is surrounded by a amnioti sack which protects andif full of amniotic fluid which cotains carbohydrates, protines and fats.

Question 6

The placenta grows

Answer 6

inside and it attatched to the uterus wall and provdes a barrier to toxins mum is exposed to (apart from nicotine and some pathogens). It transfers susbatances to baby and waste back (co2 and urea) so she can excrete them.

Question 7

FSH

Answer 7

Stimulates oestrogen in ovaries

Stimulates an egg to mature in follicle

Question 8

LH (lutenising hormone)

Answer 8

Stimulates egg release during ovulation

Question 9

Oestrogen

Answer 9

Inhibits production of FSH

Stimulates LH

Stimulates thicker uterus lining

Question 10

Progesterone

Answer 10

Inhabits production of FSH and LH

Maintains lining of uterus

Question 11

the cycle:

Answer 11

Day 1-8: menstruation

Day 8-9: possible to conceive, egg signals to ovaries as it develops, oestrogen produced, womb thickens

Day 10-14: fertile 14- folicular phase, egg leaves empty folicular cells form corpus lluteum, secretes pregancy hormones, uterus thickens

Day 15-16: possible to conceive

Day 20- egg reaches uterus

Day 17-28: thickening of uterus lining, then peirod if not fertalised.

Question 12

zygote, embryo and fetus timing

Answer 12

Zygote: 1-2 weeks

Embryo: 3-8 weeks

Fetus: 9 weeks- 9 months

Question 13

std:
virus
bacterium

Answer 13

Genital warts, herpes, HIV

Chlamydia, gonorrhoea, syphilis

Question 14

Hiv/aids

Answer 14

transmitted through: blood, semen, vaginal fluids (not salava).
Gets into blood by umprotected sex, cuts, sharing needles, mother to child in childbirth, pregancy+ breastfeeding.
It is a viral infection and weakens immune system, it develops into aids.
Hiv destroys white blood cells.
Antiretroval drugs- will keep hiv low but you have to take it for all your life, but you can still transmit. You can never remove it since it becomes a part of your cells.