Biology: Homeostasis and Response

Question 1

what is homeostasis

Answer 1

maintaining a stable internal environment

Question 2

what is negative feedback

Answer 2

action the body takes to counteract changes in levels of a substance in the body

Question 3

what happens when a substances levels are too high (3 steps)

Answer 3

receptor detects a stimulus - level is too high
the coordination centre receives and processes the information, then organise a response
effector produces a response, which counteracts the change and restores the optimum level - the level decreases

Question 4

what happens when a substances levels are too low (3 steps)

Answer 4

receptor detects a stimulus - level is too low
the coordination centre receives and processes the information, then organise a response
effector produces a response, which counteracts the change and restores the optimum level - the level increases

Question 5

what are the 5 pars of the Nervous System

Answer 5

Receptors, Sensory Neurones, CNS, Motor Neurones, Effectors

Question 6

what happens when the CNS coordinates the response

Answer 6

stimulus, receptor, sensory neurone, CNS, motor neurone, effector, response

Question 7

what are synapses

Answer 7

connection between two neurones

Question 8

what are the three parts of the brain you need to know about

Answer 8

cerebral cortex, medulla, cerebellum

Question 9

what is the function of the cerebral cortex

Answer 9

Responsible for things like consciousness, intelligence, memory and language

Question 10

what is the function of the medulla

Answer 10

controls unconscious activities like breathing and heart rate

Question 11

what is the function of the cerebellum

Answer 11

responsible for muscle coordination

Question 12

what are the 9 parts of the eye

Answer 12

suspensory ligaments
iris
cornea
pupil
lens
ciliary muscles
sclera
optic nerve
retina

Question 13

what is the sclera

Answer 13

tough supporting wall of the eye

Question 14

what is the cornea

Answer 14

transparent outer layer found at the front of the eye that refracts light into the eye

Question 15

what is the iris

Answer 15

contains muscle that allows it to control the diameter of the pupil and how much light enters the eye

Question 16

what is the pupil

Answer 16

hole in the middle of the eye

Question 17

what is the lens

Answer 17

focuses the light onto the retina

Question 18

what is the retina

Answer 18

receptor cells at the back of the eye that are sensitive to light intensity and colour

Question 19

what is the function of the ciliary muscles and suspensory ligaments

Answer 19

control shape of the lens

Question 20

what is the optic nerve

Answer 20

carries impulses from the retina to the brain

Question 21

what are the two types of muscles in the iris

Answer 21

circular muscles and radial muscles

Question 22

what does the iris do in very bright light

Answer 22

circular muscles contract, radial muscles relax which educes the diameter of the pupil

Question 23

what does the iris do in dim light

Answer 23

radial muscles contract, circular muscles relax making pupil wider

Question 24

what does the eye do when objects are close to the eye

Answer 24

ciliary muscles contract which relaxes the suspensory ligaments making the lens more curved/fat increasing the amount of refraction

Question 25

what does the eye do when objects are far away from the eye

Answer 25

ciliary muscles relax which causes the suspensory ligaments to contract making the lens thinner decreasing refraction

Question 26

what are long sighted people unable to do

Answer 26

focus on objects close to the eye

Question 27

how are they long sighted

Answer 27

lens is wrong shape and unable to correctly refract light onto the retina. The image focuses behind the retina

Question 28

what is another word for long sighted

Answer 28

hyperopia

Question 29

what are the treatments for hyperopia

Answer 29

glasses with a convex lens that refract light more bringing image closer

Question 30

what are short sighted people unable to do

Answer 30

focus on distant objects

Question 31

how are they short sighted

Answer 31

lens ins wrong shape and refracts light too much so object focuses before retina

Question 32

what is another word for short sighted

Answer 32

myopia

Question 33

what is the treatment for myopia

Answer 33

use glasses with concave lens that refracts light less pushing the focus point further back

Question 34

what are the three treatments for vision defects

Answer 34

contact lenses/glasses laser eye surgery replacement lens surgery

Question 35

how does laser eye surgery work

Answer 35

vaporises cornea tissue that is constricting the lens

Question 36

what is the internal temperature of the body and why

Answer 36

37C because it is the optimum temperature fro enzymes

Question 37

what two things happen when the body is too hot

Answer 37

sweat produced to transfer energy to environment | vasodilation - blood vessels dilate so blood flows closer to surface and transfer energy to environment

Question 38

what three things when happen when the body is too cold

Answer 38

hairs stand up to trap insulating layer of air vasoconstriction - blood vessels constrict to cut off supply to skin shivering which is auto contraction of muscles which requires respiration transferring energy

Question 39

what is the endocrine system

Answer 39

hormonal system

Question 40

what are the six organs that are part of the endocrine system

Answer 40

``` pituitary gland thyroid ovaries adrenal gland testes pancreas ```

Question 41

what hormones does the pituitary gland produce and what is their function

Answer 41

many hormones that regulate body conditions and release hormones form other glands

Question 42

what hormones does the thyroid produce and what is their function

Answer 42

thyroxine which regulates metabolism rate, heart rate, temperature

Question 43

what hormones do the ovaries produce and what is their fucntion

Answer 43

oestrogen which is part of the menstrual cycle

Question 44

what hormones does the adrenal gland produce and what is their function

Answer 44

adrenaline which prepares body for fight or flight situations

Question 45

what hormones do the testes produce and what is their function

Answer 45

testosterone which controls puberty and sperm production

Question 46

what hormones does the pancreas produce and what is their function

Answer 46

insulin which regulates blood glucose level

Question 47

what are the three differences between a nervous and hormonal response

Answer 47

nerves are fast action over a short period of time in a specific area whereas hormones are slower action over a long period of time in a general way

Question 48

what to hormones are involved in controlling blood glucose levels

Answer 48

insulin and glucagon

Question 49

what happens when blood glucose levels are too high and why

Answer 49

insulin is secreted by pancreas diffusing glucose into liver where it is converted into glycogen

Question 50

what happens when blood glucose levels are too low and why

Answer 50

glucagon is secreted by pancreas where it makes liver convert glycogen into glucose

Question 51

what is diabetes type 1

Answer 51

pancreas does not produce enough insulin

Question 52

how is type 1 diabetes treated

Answer 52

insulin injection

Question 53

what is type 2 diabetes

Answer 53

the body produces insulin but it doesn't respond to it

Question 54

how is type 2 diabetes treated

Answer 54

controlled diet and regular exercise

Question 55

what does the kidney do

Answer 55

filters blood

Question 56

what substances in the blood does the kidney filter

Answer 56

protein, cells, water, salts, minerals, urea, glucose

Question 57

what substances are extracted from the blood first

Answer 57

water, salts, minerals, glucose, urea

Question 58

what substances are diffused back into the blood stream

Answer 58

glucose, minerals, required amount of water

Question 59

what substances are sent to the bowels

Answer 59

urea, excess water and salts

Question 60

what hormones controls the concentration of urine

Answer 60

anti-diuretic hormone (ADH)

Question 61

what does more ADH mean

Answer 61

more water is reabsorbed

Question 62

what are the two treatments for kidney failure

Answer 62

dialysis, kidney transplant

Question 63

give one pro and one con of dialysis

Answer 63

no chance of rejection, time consuming/restricting

Question 64

give one pro and one con of kidney transplant

Answer 64

long term solution, chance of rejection

Question 65

what is the main reproductive hormone in men

Answer 65

testerone

Question 66

what is the main reproductive hormone in women

Answer 66

oestrogen

Question 67

how many stages are there in the menstrual cycle

Answer 67

4

Question 68

what is stage one of the menstrual cycle

Answer 68

day 1 - menstruation starts uterus lining breaks down

Question 69

what is stage two of the menstrual cycle

Answer 69

day 4-14 - uterus lining builds up again

Question 70

what is stage three of the menstrual cycle

Answer 70

egg is developed and released at day 14 also known as ovuation

Question 71

what is stage four of the menstrual cycle

Answer 71

day 14-28 - uterus lining is maintained so a fertilised egg may land

Question 72

what four hormones control the menstrual cycle

Answer 72

FSH (Follicle Stimulating Hormone), Oestrogen, LH (Luteinisng hormone), Progesterone

Question 73

where is each of the four homrones that control the menstrual cycle produced

Answer 73

FSH- Pituitary gland Oestrogen- Ovaries LH- Pituitary gland Progesterone- Ovaries

Question 74

what does each of the four hormones that control the menstrual cycle do

Answer 74

FSH- help egg mature into follicle and stimulate release of oestrogen Oestrogen- Cause uterus lining to grow and stimulate release of LH LH- stimulates ovulation Progesterone- Maintians uterus lining

Question 75

what 6 methods can be used to prevent pregnancy

Answer 75

``` condoms diaphragm spermicide sterilisation abstinence hormonal production control ```

Question 76

what two methods can be used to increase fertility

Answer 76

controlling production | IVF

Question 77

what is Auxin

Answer 77

Plant hormone that controls growth near the tips of shoots and roots

Question 78

what is Gibberellin

Answer 78

Plant hormone that controls seed germination, stem growth and flowering

Question 79

what is Ethene

Answer 79

Gas produced by ageing parts of a plant that stimulates ripening of fruit