Topic 5 - Homeostasis Question List
5.1 Homeostasis
What is homeostasis?
What does homeostasis maintain?
What does homeostasis control in the human body? (3)
Automatic control systems may involve ___________ responses or ___________ responses.
What do all control systems include? (3)
What do ___________ do?
What are stimuli?
What do ______________ _________ do?
What are 3 examples of ______________ __________?
What do ____________ do?
What can ____________ be? (2)
5.2 The Human Nervous System
5.2.1 Structure & Function
What does the human nervous system consist of?
What is the (central nervous system (CNS))?
What is the (peripheral nervous system)?
What does the nervous system enable humans to do?
(Information from _________ passes along cells (_______) as ________ ________ to the ________ _________ ________ (___).
The ____ coordinates the response of _________ which may be muscles ____________ or glands __________ __________.)
stimulus -> ___________ -> ___________ -> ___________ -> response
What are reflexes?
Why are reflexes important?
Reflexes prevent the individual from getting hurt because information travels down a pathway called a ________ ____, allowing vital __________ to take place ___________.
Reflex actions are ___________ and _______; they do not involve the ___________ part of the brain.
(A ___________ is detected by ___________.
Impulses are sent along a _________ neuron.
In the _____ the impulse passes to a _______ neuron.
Impulses are sent along a _______ neuron.
The impulse reaches an __________ resulting in the appropriate ________.)
_________ neuron -> ________ neuron -> ________ neuron
What are 2 examples of reflex arcs?
What are synapses?
(When an impulse reaches the end of the first neuron, a ______________ is released into the synapse.
This ______________ ____________ across the synapse.
When the _____________ reaches the second neuron, it triggers the ___________ to begin
again in the next neuron.)
Required Practical 7 — Reaction Time
What is reaction time?
What are possible independent variables for RP 7 — Reaction Time? (5)
What is the dependent variable for RP 7 — Reaction Time?
What are the control variables for RP 7 — Reaction Time?
What effect would practice have on reaction time?
What effect would the hand used have on reaction time?
What effect would caffeine have on reaction time?
What effect would background noise have on reaction time?
What effect would exercise have on reaction time?
Two people need to do this practical, they should both be using their dominant hand.
Person 1 sits down on the chair, with good upright posture and eyes looking across the room.
Person 1 puts the forearm of their ____________ arm across the table with their hand __________________ the edge.
Person 2 holds a ruler _______________ with the ____________ end (the end with the 0 cm mark) in between person 1’s thumb and first finger. They will tell person 1 to prepare to catch the ruler.
Person 1 catches the ruler with their thumb and first finger as quickly as possible when it drops.
Record the number on the ruler that is ________ with the top of person 1’s thumb.
Have a short rest, then repeat the test several times.
Record your results on a table.
Repeat the test with Person 2 catching the ruler and Person 1 dropping it.
Record Person 2’s results on the table.
Use a conversion table to convert your ruler measurements into reaction times.
Make the change that you are investigating to change human reaction time.
Repeat steps 1-9 for each person and record the results in your data table.
5.2.2 The Brain
What does the brain control?
The brain is made of billions of interconnected __________ and has different regions that carry out different __________.
What is the function of the cerebral cortext?
What is the function of the cerebellum?
What is the function of the medulla?
Why is investigating brain function and treating brain damage and disease difficult? (4)
What are the ways that neuroscientists can map out regions of the brain? (3)
Explain each way.
What is the advantage of studying patients with brain damage?
What is a disadvantage of studying patients with brain damage?
What is the advantage of electrically stimulating different parts of the brain?
What are the disadvantages of electrically stimulating different parts of the brain?
What are the advantages of using MRI scanning techniques?
What are the disadvantages of using MRI scanning techniques?
5.2.3 The Eye
The eye is a _______ organ containing _________ sensitive to _______ ___________ and _________.
The eye has many different structures within it. They are adapted to allow the eye to change its _______ in order to _________ on near or distant objects (a process called __________________), and to ____ light.
What is accommodation?
What does the eye do to focus on a near object?
What does the eye do to focus on a distant object?
What is the structure and function of the retina?
What is the structure and function of the optic nerve?
What is the structure and function of the sclera?
What is the structure and function of the cornea?
What is the structure and function of the iris?
What does the eye do in bright light?
What does the eye do in dim light?
What do the ciliary muscles and suspensory ligaments do?
What are two common defects of the eye?
What is (myopia) also known as?
What is (hyperopia) also known as?
What happens to the light entering your eye if you have (myopia) or (hyperopia)?
People with ___________ see close objects in clear focus, but light from distant objects is focused __ _______ __ the retina, so the images on the retina are out of ______ and ________.
What can having (myopia) be a result of? (2)
How is (myopia) commonly treated?
How do (concave) lenses work for (myopia)?
People with ____________ focus clearly on distant objects but close objects appear _________. The lens cannot ________ the rays of light __________ enough. The light is focused _________ the retina, so the images are out of ________.
What can having (hyperopia) be a result of? (2)
How is (hyperopia) commonly treated?
How do (convex) lenses work for (hyperopia)?
What are the 4 ways to treat (hyperopia) or (myopia)?
_________ _________ are lenses that are placed on the surface of the eye. They work like conventional glasses, but cannot be _______.
What are the advantages of hard contact lenses?
What are the disadvantages of hard contact lenses?
What are the advantages of soft contact lenses?
What are the disadvantages of soft contact lenses?
Some soft lenses last for a __________, but have to be removed and kept in _______ solution overnight. Others are __________ - worn for a day and thrown away.
How does (laser eye surgery) treat myopia?
How does (laser eye surgery) treat hyperopia?
What are the advantages of laser eye surgery?
What are the disadvantages of laser eye surgery?
How do (replacement lenses) work?
What are the advantages of replacement lenses?
What are the disadvantages of replacement lenses?
5.2.4 Control of Body Temperature
Body temperature is monitored and controlled by the __________________ ________ in the ________.
What does the (thermoregulatory centre) have?
The skin contains ______________ ____________ and sends __________ ___________ to the _________________ _________.
What happens when body temperature is too high?
What does your body do when the core temperature is too high?
How does vasodilation cool you down?
How does sweating cool you down?
What happens when body temperature is too low?
What does your body do when the core temperature is too low?
How does vasoconstriction warm you up?
How does stopping sweat production warm you up?
How does shivering warm you up?
5.3 Hormonal Coordination in Humans
5.3.1 Human Endocrine System
The endocrine system is composed of ________ which secrete chemicals called ___________ directly into the ____________. The blood carries the _________ to a _______ ________ where it produces an _______. Compared to the nervous system the effects are _________ but act for _______.
The pituitary gland in the brain is a ‘_____ _______’ which secretes several __________ into the blood in response to body conditions. These hormones in turn act on other _________ to _________ other hormones to be released to bring about ________.
What hormones does the pituitary gland secrete and what are these hormones’ functions?
Label each part:
What hormone does the pancreas secrete and what is that hormone’s function?
What hormone does the thyroid secrete and what is that hormone’s function?
What hormone does the adrenal gland secrete and what is that hormone’s function?
What hormone does the ovary secrete and what is that hormone’s function?
What hormone does the testes secrete and what is that hormone’s function?
5.3.2 Control of Blood Glucose Concentration
What is blood glucose concentration monitored and controlled by?
Eating foods that contain ______________ increases the glucose levels in the blood.
What happens if blood glucose concentration is too high?
Rigorous activity, (e.g. _______), uses ________ for _________ and therefore there is less in the blood.
What happens if blood glucose concentration is too low?
Control of blood glucose concentration is an example of __________ _________.
What is insulin?
What is glycogen?
What is glucagon?
What causes type 1 diabetes?
What are the main risk factors for type 1 diabetes?
What causes type 2 diabetes?
What are the main risk factors for type 2 diabetes?
What are the characteristics of type 1 and type 2 diabetes?
How is type 1 diabetes treated? (2)
How do insulin injections help treat type 1 diabetes?
How does a low carbohydrate diet help treat type 1 diabetes?
What are 3 ways to treat type 2 diabetes?
What types of drugs are there to treat type 2 diabetes? (3)
5.3.3 Maintaining Water & Nitrogen Balance in the Body
Water leaves the body via the ________ during _________. _______, ______, and ______ are lost from the skin in sweat. There is no control over ______, ____, or ______ loss by the _______ or skin.
Carbon dioxide __________ out of the cells into your blood down a ___________ ________. It then ________ from the ________ into the air in the ________ of your lungs. This air containing the excreted carbon dioxide is removed from your body when you ________. As a side effect of exhalation, you lose ________ when the moist air from inside your lungs is forced out of your body.
What is osmosis?
Excess water, ions and urea are removed via the _________ in the _______. If body cells lose or gain too much water by _________ they do not function efficiently.
What does the digestion of proteins from the diet result in?
Where in the body are amino acids are deaminated to form ammonia?
Ammonia is ______ and so it is immediately converted to ______ for safe __________.
The carbon dioxide made by the body cells during __________ must be removed, because dissolved carbon dioxide produces an ________ solution. This change in pH would affect the working of all the __________ in the cells.
How is urea produced?
How is urea removed from the body?
What do the kidneys do?
How do the kidneys work?
Which gland is ADH (anti-diuretic hormone) secreted by?
_________ cells in the brain detect the concentration of ________ in the blood plasma.
What happens if the water concentration in the blood is too high (solute concentration is too low/dilute)?
What happens if the water concentration in the blood is too low (solute concentration is too high/concentrated)?
The control of water concentration in the blood is an example of ___________ __________.
What are 2 ways that kidneys can be damaged and/or destroyed?
What are 2 ways of treating kidney failure?
What happens if kidney failure is left untreated?
How does dialysis work?
What is the concentration of glucose in dialysis fluid?
What is the concentration of mineral ions in dialysis fluid?
What is the concentration of urea in dialysis fluid?
Explain the movement of glucose during dialysis.
Explain the movement of mineral ions during dialysis.
Explain the movement of urea during dialysis.
What is the final concentration of glucose in the blood after dialysis?
What is the final concentration of mineral ions in the blood after dialysis?
What is the final concentration of urea in the blood after dialysis?
Why must patients on dialysis control their protein intake?
Why must patients on dialysis control their salt intake?
What is the advantage of dialysis?
What are the disadvantages of dialysis?
How do kidney transplants overcome the problem of kidney failure?
What is the main problem with a kidney transplant?
Why may the patient’s body reject the donor kidney?
What are the ways to reduce the chance of rejection? (2)
What is the advantage of using immunosuppressant drugs?
What are the disadvantages of using immunosuppressant drugs?
What are the advantages of a kidney transplant?
What are the disadvantages of kidney transplants?
5.3.4 Hormones in Human Reproduction
What are the primary sexual characteristics in males?
What are the primary sexual characteristics in females?
What is the main reproductive hormone in males?
Where is testosterone produced?
What does testosterone do?
What is the main reproductive hormone in females?
Where is oestrogen produced?
How long is the menstrual cycle?
What day does ovulation occur?
What hormones are involved in controlling the menstrual cycle? (4)
What is ovulation?
Where is follicle stimulating hormone (FSH) produced?
Where is luteinising hormone (LH) produced?
Where is progesterone produced?
Menstrual Cycle:
Roles of Hormones:
FSH:
Secreted by _________ ________
Makes eggs ________ in their follicles in the _______
Stimulates ________ to produce __________
Oestrogen:
Made and secreted by _________
in response to ______
Stimulates the lining of the _______ to grow after menstruation
High levels of oestrogen:
inhibit the production of more _____
stimulate the release of ___
LH:
Secreted by _________ _______
Stimulates the release of a _______ egg from the ______
After _________, LH levels fall
Progesterone:
Secreted by ________ ____ _______ in the _____ after _________
Helps maintain pregnancy if the egg is __________
Maintains the lining of the _______ in the second half of the cycle
Inhibits _____ and ___
Cycle:
If the egg is not fertilised:
Levels of all hormones drop
Lining of the uterus pulls away and is lost from the body (period)
New cycle begins — levels of ______ and ________ increase
The interaction between FSH and oestrogen is an example of __________ __________.
What hormone does FSH stimulate the production of?
What hormone does oestrogen stimulate the production of?
What hormone does oestrogen inhibit the production of?
What hormones does progesterone inhibit the production of?
5.3.5 Contraception
What is contraception?
Fertility can be controlled by a variety of ___________ and ____________ methods of contraception.
What are the hormonal methods of contraception? (2)
What are the non-hormonal methods of contraception? (4)
Combined Pill:
The combined pill is an ____ _____________.
It contains low doses of ___________ along with some ______________.
The hormones inhibit the production and release of ________ by the __________ _________. As a result, no eggs _____ in the _________, preventing pregnancy.
The pill hormones also stop the ______ _______ developing, preventing ___________, and make the _______ in the cervix ______ to prevent sperm getting through.
What are the advantages of the combined pill?
What are the disadvantages of the combined pill?
Progesterone-only Pill:
It is an ____ ____________ that only contains progesterone
prevents the _______ from releasing the egg
thickens the _______ in _______ so sperm cannot swim
stops ________ eggs from ___________ in the uterus
_______ side effects than the combined pill
It is especially important to take the progesterone-only pill very regularly otherwise:
the artificial __________ levels drop
the body's own hormones take over very ________
may lead to the unexpected release of an ______ when a person thinks they are protected from ___________
What are the advantages of the progesterone-only pill?
What is the disadvantage of the progesterone-only pill?
Contraceptive Injections:
Made up of ______________
prevents the ________ from releasing the egg
thickens the _______ in _______ so sperm cannot swim
stops _________ eggs from ____________ in the uterus
Lasts for 2 to 3 months
Contraceptive Implants:
Releases a continuous amount of ____________
prevents the ______ from releasing the egg
thickens the ________ in _______ so sperm cannot swim
stops ___________ eggs from ____________ in the uterus
Lasts for 3 years
Contraceptive Patches:
It contains ___________ and _____________.
The hormones inhibit the production and release of _____ by the __________ _______.
As a result, no eggs _______ in the ________, preventing pregnancy.
The hormones also stop the _______ _______ developing, preventing ____________, and make the _______ in the cervix _______ to prevent sperm getting through.
It is a small patch that is stuck on the skin
It lasts a week
What are the advantages of contraceptive injections, implants, and patches?
What are the disadvantages of contraceptive injections, implants, and patches?
What are spermicides?
What are the two barrier methods of contraception?
What is a condom and how does it prevent pregnancy?
What are the advantages of condoms?
What is the disadvantage of condoms?
What is a diaphragm and how does it prevent pregnancy?
What are the advantages of diaphragms?
What are the disadvantages of diaphragms?
Intrauterine Devices (IUDs):
Inserted into the uterus by a doctor
Lasts 3 - 5 years
Plastic IUDs:
Releases ____________
prevents the ______ from releasing the egg
thickens the ________ in _______ so sperm cannot swim
stops ___________ eggs from ____________ in the uterus
Copper IUDs:
Kills any _____ in the uterus
Stops ___________ ________ from ___________ in the _______ _______
What are the advantages of intrauterine devices?
What are the disadvantages of intrauterine devices?
What is abstinence and how does it prevent pregnancy?
What is a vasectomy and how does it prevent pregnancy?
What is female sterilisation and how does it prevent pregnancy?
What is the advantage of surgical methods of contraception?
What are the disadvantages of surgical methods of contraception?
5.3.6 The Use of Hormones to Treat Infertility
Fertility drugs are used to increase the chance of ______________.
The main hormones used are _____ and _____ because they stimulate the maturation and release of the ______.
The woman can then become pregnant normally.
In-Vitro Fertlisation (IVF)
IVF involves giving a mother ______ and ____ to stimulate the maturation of several eggs.
The eggs are collected from the mother and fertilised by ________ from the father in the laboratory.
The fertilised eggs develop into __________.
At the stage when they are tiny balls of cells, one or two embryos are inserted into the mother’s ______ (womb).
What are the advantages of IVF?
What are the disadvantages of IVF?
What are the ethical issues surrounding IVF?
5.3.7 Negative Feedback
Describe how a negative feedback system works.
Adrenaline is produced by the ________ _________ in times of fear or stress. It increases the ______ ______ and boosts the delivery of _________ and _________ to the _______ and _________, preparing the body for ‘flight or fight’.
Thyroxine from the _________ ________ stimulates the ______ ___________ _____. It plays an important role in _________ and _____________.
What does adrenaline cause in your body? (5)
Does adrenaline involve a negative feedback loop?
Thyroxine, TSH (Thyroid Stimulating Hormone) & Negative Feedback
If levels of __________ in the blood begin to fall, it is detected by sensors in the brain.
The ________ _______ releases more TSH.
TSH stimulates the production of __________ by the ________ ________.
As the level of __________ goes up, it is detected by the sensors in the brain.
As a result, the level of TSH released by the _______ ______ falls.
5.4 Plant Hormones
5.4.1 Control & Coordination
What is phototropism?
What is gravitropism/geotropism?
Name 3 plant hormones.
Plants produce hormones to coordinate and control growth and responses to light (___________) and gravity (__________ or __________). Unequal distributions of _______ cause unequal growth rates in plant roots and shoots.
Most plants show __________ ______________ because they grow towards the light source.
Positive Phototropism in Plant Shoots:
The plant is exposed to ______ on one side.
________, a hormone, moves to the ________ side of the shoot.
_______ stimulates cells to grow _____ here.
This means the shoot bends ______ the light.
The plant receives ______ light, meaning ____________ can occur at a ______ rate.
Most shoots show ________ ___________ as they grow away from gravity.
Negative Gravitropism in Plant Shoots:
If a shoot is horizontal:
Auxin moves to the ______ side.
The cells of the shoot grow ______ on the side with most auxin, so it stimulates cells to grow _____ here.
This makes the shoot _______ and grow away from the _______.
This is beneficial as light levels are likely to be higher ________ ______ from the ground.
Most roots show __________ _____________ as they grow towards gravity.
Positive Gravitropism in Plant Roots:
If a root is horizontal:
Auxin moves to the _______ side.
The cells of the root grow more on the side with ______ auxin, so it stimulates cells to grow on the ______ side.
This makes the root bend and grow _________.
This is beneficial as there are more likely to be increased levels of _______ and ________ lower down, and it provides _______ for the plant.
When the auxin distribution becomes equal on both sides it grows ________ in that direction.
What do gibberellins do?
What does ethene do?
Required Practical 8 — Plant Responses
What is the independent variable in RP 8?
What is the dependent variable in RP 8?
What are the control variables in RP 8?
What are the sources of error in RP 8? (3)
In RP 8, which group of seedlings would you expect to grow the most and why?
In RP 8, why is it necessary to find the mean height of the seedlings?
In RP 8, why must you hold the seedlings straight when you are measuring them?
1. Put 10 mustard seeds in three petri dishes on damp cotton wool.
2. Put the dishes in a warm place to germinate.
Temperature, amount of seeds, and amount of water should be the same.
Water daily with equal amounts of water to each dish.
3. Measure the initial height of each seedling in mm using a ruler.
4. Put one petri dish in each place:
full sunlight
partial light
darkness
5. Measure the height of every seedling for 5 days.
6. Calculate the mean height of the seedlings every day.
5.4.2 Use of Plant Hormones
What are auxins used for? (3)
What is ethene used for?
What are gibberellins used for? (3)
Why can auxins be used for rooting powders?
Why can auxins be used for weed killers?
Why is ethene used for food transport?
Why can gibberellins be used to end seed dormancy?
Why can gibberellins be used to promote flowering?
Why can gibberellins be used to increase fruit size?