Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology Paper 2 > Homeostasis And Response > Flashcards

Homeostasis And Response Flashcards

(74 cards)

Start Studying
1
Q

What is homeostasis

A

The regulation of the internal conditions of a cell or organism to maintain optimum conditions for function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What happens if conditions are not optimal

A

Enzymes start to denature. This reduces their ability to catalyse metabolic reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does homeostasis regulate

A

Water levels
Blood glucose concentration
Body temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What do control centres include

A

Receptors
Coordination centres
Effectors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are receptors

A

Detect changes in environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are co ordination centres

A

Receive and process information from receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are effectors

A

(Muscles or glands) the bring about a response which restores optimum levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does the nervous system do

A

Protects organisms from harm by responding to changes in the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the process for a response

A

1) receptor cells convert a stimulus into an electrical impulse
2)this electrical impulse travels along cells called sensory neurones to the CNS
3) Here, the information is processed and the appropriate response is co ordinated resulting in an electrical impulse being sent along motor neurones to effectors
4)the effectors carry out the response. This may be muscles contracting or glands secreting hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the central nervous system made up of

A

The brain
The spinal chord
Neurones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are synapses

A

Gaps between neurones. Nerve impulses must travel across the gaps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why are reflexes important

A

They prevent the individual from getting hurt. This is because the information travels down a pathway called a reflex arc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a sensory neurone

A

Carries signal in form of electrical impulse to the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a relay neurone

A

Relays the electrical impulse from the sensory neurone to the appropriated motor neurone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the motor neurone

A

Another nerve cell that carries the electrical impulse from the CNS to the effector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the process of a reflex

A

1)stimulus is detected by a receptor
2)impulses are sent along a sensory neurone
3)in the CNS impulses passes to a relay neurone
4)impulse sent down a motor neurone
5)reacher an effector resulting in a response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the process of synapses

A

1)the electrical impulse reaches the end of the neurone before the synapse
2)this triggers the release of chemicals called neurotransmitters
3)the neurotransmitters diffuse across the synapse
4) the neurotransmitters bind to receptors on the next neurone
5) the presence of the neurotransmitters causes the production of an electrical impulse in the next neurone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are examples of voluntary actions

A

Drinking
Talking
Running

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are examples of reflex actions

A

Blinking
Coughing
Yawning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the reaction time required practical

A

1) Sit down on the chair and place your forearm of the non dominant hand on the table with your hand hanging over the end of the table
2) have your partner hold a ruler with the bottom end in between your fingers so you can practice holding the ruler with 2 fingers
3)have your partner hold the ruler and remove your fingers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Reaction time (2)

A

4)have your partner hold the ruler in line so that 0 mark is level with the top of your thumb
5)your partner will drop the ruler without telling you beforehand and you’ll catch the ruler as quickly as you can
6) note and record the number level with the top of your thumb after you’ve caught the ruler in a table such as below

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Reaction time (3)

A

7) repeat the test at least 5 times
8) swap places with your partner and repeat steps 1-7
9) find reaction times by using a conversion table to convert the ruler measurements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the sources of error

A

Participants may have different experiences in performing a similar task previously

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are hormones

A

Chemicals made and released by glands. They travel around the body in the blood to their target organ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the endocrine glands
Testes Ovary Pituitary gland Adrenal glands Pancreas Thyroid glands
26
What is the pituitary gland
The master gland Secrètes hormones into the blood to either have an effect on the body or act on other glands to stimulate them to produce different hormones
27
What is the pancreas
Secretes insulin Controls blood glucose levels
28
What are the thyroid glands
Secretes thyroxine Controls metabolic rate, heart rate and temperature
29
What are adrenal glands
Secretes adrenaline Involved in the “fight” or “flight” response
30
What are the ovaries
Secretes oestrogen Involved in the menstrual cycle and the development of female secondary sexual characteristics
31
What are the testes
Secretes testosterone Involved in the production of sperm and the development of male secondary sexual characteristics
32
What are the differences between the central nervous system and the endocrine system
CNS-triggers rapid response Endocrine-triggers slower response CNS-uses electrical signals carried by neurones Endocrine-uses chemical messagers carried by blood CNS-response is very short Endocrine-response can be long lasting CNS-acts on a precise part of body Endocrine-acts on large areas of the body
33
Why is the pituitary gland the master gland?
It produces multiple hormones and tells other glands to release their hormones. It secretes several chemicals and hormones into the blood in response to the body conditions. These hormones in turn act on other glands to stimulate other hormones into the blood in response to body conditions
34
What happens if there’s a high concentration of glucose in the blood
Water moves out of the cells by osmosis across a partially permeable membrane from an area of high water concentration so cells will shrink
35
What if there’s a low concentration of glucose in the blood
Water moves into the cells by osmosis across a partially permeable membrane from an area of high water concentration do cells will grow
36
What happens when there’s an increase in blood sugar
When there’s an increase in blood sugar for example eating, the pancreas detects a rise in blood sugar and releases insulin into the blood. All the cells take in glucose. Liver and muscles turn excess glucose into glycogen and blood sugar falls.
37
What happens when there’s decrease in blood sugar
When there’s a decrease in blood sugar for example exercise, pancreas detects the drop in blood sugar and releases glucagon in the blood which increases the blood glucose concentration. Glycogen in liver is broken down and glucose is released in the blood
38
What does blood glucose concentration work in
Negative feedback loop
39
How does the negative feedback loop create an opposite effect
The action of this hormone cannot occur continually because when the blood arrived at a certain glucose concentration the other hormone is produced resulting in the opposite effect
40
What is type 1 diabetes
A disorder in which the pancreas fails to produce sufficient insulin.
41
What is type 2 diabetes
The body cells no longer respond to insulin produced by the pancreas l
42
What are the differences between type 1 and 2 diabetes
Type 1-can be managed but not cured Type 2- may be cured Type 1-appears in children/young adults Type 2-affects older/overweight people Type 1-caused by Type 2-caused by
43
What are the treatments of type 1 diabetes
Insulin injections Pancreatic cell transplants Manage diet, exercise regularly
44
What are the treatments of type 2 diabetes
Injections don’t help-body doesn’t respond to insulin Losing weight Increasing exercise Drugs to make insulin more effective on body cells
45
Why are insulin injections better than pancreatic transplants
Pancreatic transplants are complex surgery, high risk and expensive Injections are widely available, self administered and cheap
46
What are the secondary sex characteristics in men during puberty
Testosterone rises Underarm, facial and Pubic hair grows Voice deepens
47
What are the secondary sex characteristics in women during puberty
Oestrogen rises Triggers menstrual cycle Underarm and pubic hair grows Breasts enlarge
48
What is the menstrual cycle
A monthly cycle which involves the maturation and release of an egg. If sex has occurred this can result in pregnancy
49
What are the 4 hormones involved in the menstrual cycle
FSH (follicle stimulating hormone) LH (luteinising hormone) Oestrogen Progesterone
50
What does FSH do
Released by the pituitary gland and causes egg in ovary to mature Stimulates production of oestrogen
51
What does oestrogen do in the menstrual cycle
Released in ovaries. Causes development of uterus lining. Stimulates production of LH and stops production of FSH
52
What does LH do in the menstrual cycle
Produced by pituitary gland and stimulates release of mature egg on day 14 of cycle This is called ovulation
53
What does progesterone do in the menstrual cycle
Produced in ovaries after ovulation. Maintains lining of uterus during days 14-28. When progesterone levels drop, this triggers the breakdown of the lining Stops release of FSH + LH
54
What are the stages of the menstrual cycle
1) (day 1-4) Progesterone levels drop meaning uterus lining breaks down resulting in a period 2) (day 4-14) due to oestrogen the uterus lining starts to develop 3) (day 14)- ovulation occurs from LH. FSH causes ovary to mature and this releases a mature egg 4) (day 15-28) the rise in progesterone maintains the uterus lining meaning that it’s now ready for the arrival of a fertilised egg. If no fertilised egg is attached to the uterus lining, the lining breaks down and the cycle begins again. If there’s a fertilised egg attached then pregnancy occurs
55
What is the difference between hormonal and non hormonal methods of contraception
Non hormonal- stop the sperm and egg meeting Hormonal-use hormones to prevent the egg maturing or being released
56
What are the features of a contraceptive pill
Mixed pill contains oestrogen and progesterone TMT oestrogen levels are constantly high inhibiting FSH so no eggs mature The lining also stops developing and the mucus in the cervix becomes thick so sperm can’t move through Possible side effects include-mood swings, depression, breast pain, increased blood pressure Progesterone only pill- has less side effects stimulates production of mucus which is difficult for sperm to penetrate
57
What are the features of contraceptive patches
Contains oestrogen and progesterone Small and stuck on the skin Lasts for one week
58
What are the features of contraceptive implants
Releases a continuous amount of progesterone Prevents the ovaries from releasing the egg thickens the mucus in cervix do sperm cannot swim and stops fertilised eggs from embedding in the uterus Lasts for three years
59
What are the features of contraceptive injections
Made up of progesterone Same effect as the implant Last for 2-3 months
60
What are the features of plastic IUD S
Releases progesterone Same effect as implant T shaped- inserted into uterus
61
What are spermicide- non hormonal
A fluid used which kills or disables sperm but are only 70-80% effective
62
What are features of condoms and diaphragms (non hormonal)
Condoms are either worn over the penis or inside the vagina. They also prevent the individual from contracting STDs. A problem however is it can tear and let sperm through A diaphragm is a plastic cup which is positioned over the cervix. It’s used with speemicide
63
How do copper IUDs work
Work by killing sperm in the uterus and stopping any fertilised embryos from implanting in the uterus lining
64
How does sterilisation work
A permanent procedure. For a man it involves cutting the sperm duct so the sperm isn’t released in ejaculation For women this involves cutting the oviduct so that an egg can’t reach he uterus
65
What are the natural methods of contraception
Timing-some women avoid sex ok days when they know they are ovulating. However it’s not as effective as sperm can last up to 6 days inside the womens body Abstinence-a couple chooses not to have sex unless ready for a baby
66
What are fertility drugs used for
To increase chances in pregnancy The main hormones used are FSH and LH because they stimulate the maturation and release of an egg. The woman can then become pregnant normally
67
What happens in IVF treatment
IVF involves giving a mother FSH and LH to stimulate the maturation of several eggs. The eggs are collected from the mother and fertilised by sperm from the father in a laboratory The fertilised eggs develop into embryos At the stage when they are tiny balls of cells, one or two embryos are inserted into the mothers uterus
68
What are the benefits of IVF
provides a way for an infertile couple to have a child
69
What are the disadvantages of IVF
It’s physically stressful as women may have reactions to the hormones such as feeling sick It’s emotionally stressful because it may not work. The success rate for IVF is 26% It can lead to multiple births- unexpected and may be a risk to the babies and the mother Can be expensive if the process needs to be repeated
70
What does thyroxine do
Regulates metabolic rate. It’s also important in growth an development by stimulating protein synthesis Released by the thyroid gland Release is stimulated by the thyroid stimulating hormone
71
What is thyroxine in negative feedback
When the levels increase it’s detected by the receptors in the brain This inhibits the release of TSH this inhibits the release of thuroxine so levels fall
72
What does adrenaline do
Produced in times of stress and stimulates the “fight” or “flight” response Released by the adrenal glands Stimulated by fear or stress detected in the brain
73
What organs does adrenaline carry around
Heart Lungs Liver Eyes Brain
74
What are the effects of adrenaline
Increased heart rate and breathing rate to deliver more oxygen and glucose to the brain and muscles for resperation Glycogen stored in liver is converted to glucose for resperation Pupils dilate to let in more light Blood flow to muscles is increased Blood flow to digestive system increased

Biology Paper 2 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions