homeostasis and response

Question 1

what’s a nerve cell

Answer 1

adapted to carry electrical impulses from one place to another

Question 2

how is a nerve cell adapted

Answer 2

long
th in
lots of branches
increase surface area

Question 3

what is a synapse

Answer 3

a gap between neurones which chemical messengers diffuse across

Question 4

what is the refelx arc cycle

Answer 4

stimulus
receptor
sensory neurone
CNS
relay neuron
motor neurons
effector
response

Question 5

what is one way to remember reflex arc

Answer 5

SILLY
RABBITS
SEE
CONNIE
REALLY
MOVING
EVERY
RESPONSE

Question 6

6 marker about hot pans

Answer 6

The heat stimulus is detected by temperature receptors in the skin

electircal impulse carried from the sensory neurone to the CNS

chemical transmission across synapse
via relay neurone

electrical impulse carried from motor to the effector

muscle contracts moving the hand away

Question 7

what are all diffrent parts of the brain and what do they do

Answer 7

cerebral cortex( big bit)
controls consciousness, memory, senses, language, intelligence

cerebellum
bottom right
controls coordination and balence

medulla (long tail)
controls unconcious activity’s (e.g breathing)

hypothalamus (regulate body temp)

Question 8

what are some ways that scientists study the brain

Answer 8

study people with brain damage
electrically stimulate diffrent parts of the brain

scan

Question 9

why is treating the brain so difficult

Answer 9

wide range of things that could go wrong
brain is so complex and hard to understand
brain tissue is fragile

Question 10

what does each part of the eye do

Answer 10

Iris - controls size of the pupil
Lens- Can change its shape to controls light refraction
retina -
optic nerve- impulses generated by receptor cells

cornea- transparent and has no blood vessels

Question 11

what does the eye do when it’s dark or light

Answer 11

dark = circular muscles relax and radial muscles contract

light= radial muscles relax
circular muscles contract

Question 12

describe oral contraceptives (e.g pill)

Answer 12

it’s hormonal
prevents the body from producing FSH( hormone that causes egg to mature)

advantage - highly effective if taken correctly

disadvantage- must remeber to take it everyday
may have side effects
doesn’t protect against STIS

Question 13

describe implant, injection , skin patch

Answer 13

hormonal contraception
contains progesterone that stops egg from maturing or being released

advantage - more convinuent that taking a daily pill

disadvantage- dosent protect against STIS

Question 14

explain barrier method of contraception ( condom)

Answer 14

non hormonal
prevents the sperm from reaching the egg as it acts as a barrier

advantage- protects against STIS
no side effects

disadvantage- may break
not entirely effective

Question 15

explain spermicide

Answer 15

kills sperm

Question 16

explain IUD (coil)

Answer 16

hormonal
prevents embryo from implanting
releases hormones to reduce chances of fertilisation

advantage- highly effective
lasts a long time

disadvantage- does not protect against STIS

Question 17

explain sterilisation

Answer 17

surgical method of conraception
women- prevents egg from reaching the uterus

men - prevents sperm from leaving the penjs

advantage
highly effective

disadvantage- hard to reverse
doesn’t protect against STIS

Question 18

explain abstinence

Answer 18

natural form of contraception
not having sexual intercourse when the woman is ovulating

disadvantage- hard to tell when a woman is ovulating
doesn’t protect against STIS

Question 19

Why are contraceptions controversial

Answer 19

Catholic church teaches that all contraption exempt natural ones are unethical

other people believe it’s their right to choose and condoms actually reduce the risk of STIS

Question 20

what does FSH do

Answer 20

hormone that trigger egg to mature

Question 21

what does LH do

Answer 21

triggers the mature egg to be released

Question 22

what is the process of IVF

Answer 22

happens in labs

1) mother is treated with FSH and LH
2) causes several eggs to mature
3) collects egg from mother
4) collects sperm with father
5) fertiles them
6) fertilised eggs turn into embryos
7) embryos are inserted into mothers uterus

Question 23

what are some problems with IVF

Answer 23

success rates aren’t that high
emotionally and physically stressful
can lead to multiple births

unethical - embryos that aren’t transferred are destroyed
people believe they are killing human life and others believe it’s just a ball of cells.

Question 24

what is the stem response to light stimulus

Answer 24

positive phototropism
bends towards the light

Question 25

what is the roots response the force of gravity stimulus

Answer 25

positive geotropism
bends towards the force of gravity

Question 26

where is auxin made

Answer 26

meristem

Question 27

howdoes auxin affect a plant

Answer 27

changes the rate of elongation in plants , changing their length

Question 28

what happens the cells in stem and root when there is a high concentration of auxin

Answer 28

cells in stem grow more
cells in root grow LESS

Question 29

how does phototropism work

Answer 29

higher concentration of auxin so it elongates the cell causing the stem to bend towards the light

Question 30

how does gravititropisms work

Answer 30

growth response to the force of gravity

if a root contains more auxin , it grows less

bends towards the force of gravity