Topic 1 - Control Systems Flashcards
1
Q
What are the 3 main roles of the kidney?
A
- Remove urea from blood; urea produced in liver from breakdown of excess amino acids
- Adjust ion levels in blood
- Adjust water content of blood
2
Q
What are the 3 main processes that happen in the nephrons in the kidney?
A
- Ultrafiltration
- Reabsorption
- Release of waste
3
Q
How do the nephrons in the kidney undergo ultrafiltration?
A
- High pressure built up, squeezing out water, urea, ions, glucose out of blood to Bowman’s capsule
- Glomerulus + Bowman’s capsule act like filters, big molecules like proteins + blood cells stay in blood (not squeezed out)
4
Q
How do the nephrons in the kidney undergo reabsorption?
A
- All glucose is selectively reabsorbed (moved out of nephron back into blood against concentration gradient)
- Sufficient water is reabsorbed by how much ADH hormone present
5
Q
What is the process that maintains a constant water level in the body?
A
Osmoregulation
6
Q
What are the blood vessels going into and out of the nephron for filtration?
A
- Renal artery in
- Renal vein out
7
Q
How do the nephrons in the kidney release wastes?
A
- Urea + excess water not reabsorbed
- Continue out of nephron, into ureter + to bladder as urine
8
Q
Where is urine released from?
A
Urethra
9
Q
What does ADH stand for (hormone)?
A
- Anti diuretic hormone
- Controls amount of water reabsorbed in the kidney
10
Q
Where is ADH released from?
A
Pituitary gland
11
Q
What part of the body monitors water content of the blood and instructs pituitary gland to release ADH?
A
Brain
12
Q
Osmoregulation is done by what system?
A
Negative feedback (changes in environment trigger a response to counteract changes so internal environment stay around a norm at which cells work best)
13
Q
Through the use of ADH, what does the body do when the water content of the blood gets to high or too low?
A
- Water loss–>brain detects water loss–>pituitary gland releases more ADH–>ADH makes kidney reabsorb more water–>hydrated
- Water gain–>brain detects water gain–>pituitary gland releases less ADH–>lack of ADH means kidney reabsorbs less water–>hydrated
14
Q
What can a person with kidney failure have?
A
Dialysis machine
15
Q
What does a dialysis machine do?
A
Filters the blood for people with kidney failure
16
Q
How does dialysis work?
A
- Has to be done regularly to keep dissolved substances at right concentrations/remove waste
- Dialysis fluid has same concentration of salts/glucoe as blood plasma (so aren’t removed from blood)
- Barrier is permeable to ions/waste substances but not big molecules e.g. proteins (like kidney); waste substances/excess ions/water move from blood across membrane to dialysis fluid
17
Q
What can someone with a kidney disease have?
A
Kidney transplant
18
Q
In a kidney transplant, what measures are taken to minimise rejection?
A
- Donor has tissue type that closely matches patient
- Patient treated w/ drugs that suppress immune system so won’t attack transplanted kidney
19
Q
What is the main functions of an egg cell?
A
- Carry female DNA
- Nourish developing embryo in early stages
20
Q
What are the features of an egg cell?
A
- Contains nutrients in cytoplasm to feed embryo
- Straight after fertilisation (when sperm fuses w/ egg). egg’s membrane changes structure to stop more sperm getting in so offspring has right amount of DNA
- Haploid nucleus so when fertilised the cell has right number of chromosomes
21
Q
What is the main function of a sperm cell?
A
Transport male’s DNA to female’s egg cell so DNA can combine
22
Q
What are the main features of a sperm cell?
A
- Small w/ long tails so can swim to egg
- Lots of mitochondria in middle providing energy (from respiration) needed to swim distance
- Have acrosome at front of head, where enzymes stored to digest through membrane of egg cell
- Haploid nucleus
23
Q
What does haploid nucleus mean?
A
- 23 chromosomes
- One copy of each chromosomes
- No pairs
- Half the number of chromosomes
24
Q
What are the 4 stages of the menstrual cycle?
A
1) Day 1: start of bleeding; uterus lining breaks down + is released (menstruation)
2) Days 4-14: lining of uterus builds up again into thick spongy layer of blood vessels ready to receive fertilised egg
3) Day 14: egg released from ovary (ovulation)
4) Days 14-28: Lining is maintained; if no fertilised eff landed on uterus by day 28 spongy lining breaks down + process restarts
25
What are the 4 hormones that control the menstrual cycle?
- FSH (follicle stimulating hormone)
- Oestrogen
- LH (luteinising hormone)
- Progesterone
26
What is the role of the FSH in the menstrual cycle?
- Causes follicle (egg + surrounding cells) to mature in one of the ovaries
- Stimulated oestrogen production
27
What is the role of the oestrogen in the menstrual cycle?
- Causes lining of uterus to thicken + grow
| - High level stimulates LH surge (rapid increase)
28
What is the role of the LH in the menstrual cycle?
- LH surge stimulated ovulation at day 14; follicle ruptures + egg released
- Stimulates remains of follicle to develop into structure called corpus luteum, secreting progesterone
29
What gland is progesterone secreted from?
Corpus luteum
30
What is the role of the progesterone in the menstrual cycle?
- Maintains lining of uterus
- Inhibits production of FSH + LH
- When level of progesterone falls + low oestrogen level, uterul lining breaks down
- Low progesterone level allows FSH to increase
31
What happens to the hormone levels if pregnancy occurs?
Progesterone stays high to maintain lining of uterus
32
What happens to the uterus lining during pregnancy?
-Uterus has thick spongy layer of blood vessels; blood supply allows placenta to develop
33
What is the role of the placenta during pregnancy?
- Supplies baby w/ oxygen, glucose + nutrients needed to grow
- Removes waste products like urea + carbon dioxide
34
What system controls levels of hormones in the menstrual cycle?
- Negative feedback
- e.g. FSH stimulates ovary to release oestrogen, oestrogen inhibits release FSH from pituitry gland in brain; after FSH caused follicles to mature, negative feedback keeps FSH level low o no mroe follicles mature
35
How can hormones be used to increase fertility?
- Some women have FSH levels too low for follicles to mature so no eggs released + women can't get pregnant
- FSH + LH can be injected by women to stimulate egg release in ovaries
36
What are the advantages of using hormones to increase fertility?
Helps women get pregnant when they otherwise wouldn't be able to
37
What are the disadvantages of using hormones to increase fertility?
- Not always successful so often has to be repeated + can be expensive
- Too many eggs can be stimulated, so unexpected multiple pregnancies
38
How can IVF be used to help couples have children?
- In vitro fertilisation
- Eggs collected from woman's ovaries + fertilising them in lab using man's sperm; grown into embryos
- One embryos are tiny ball of cells, 1-2 transferred to woman's uterus (womb) to increase chance of pregnancy
- FSH + LH given before collection to stimulate egg production so more than 1 egg can be collected
39
What are the advantages of using IVF to help couples have children?
Can give infertile couple a child
40
what are the disadvantages of using IVF to help couples have children?
- Some women have strong reaction to hormone (abdominal pain, vomitting, dehydration)
- Reports of increase of cancer from hormonal treatment but some say no risk; unsure
- Can result in multiple births if more than embryo grows into baby; risk to mother
41
How can IVF be done with donated eggs?
Women who can't produce eggs can use an egg from donor to have IVF to conceive
42
What are the advantages of using IVF with donated eggs?
- Women who can't produce eggs can have a baby
| - Prevents risk of passing genetic disorder from mother
43
What are the disadvantages of using IVF with donated eggs?
Emotionally difficult as baby has different genetic mother
44
How can a surrogate mother be used to help a couple have a child?
- If women can't become pregnant, may ask another woman to carry baby for her
- Women who carries baby known as surrogate mother
- IVF used to produce embryo, either using egg + sperm from couple or donor egg + sperm
- Embryo implanted into surrogate mother's uterus
- After birth, woman gives baby to couple
45
What are the advantages of using a surrogate mother to help a couple have a child?
Allows couple to have children if medical problems mean women can't become pregnant or risky for her to give birth
46
What are the disadvantages os using a surrogate mother to help a couple have a child?
- Surrogate mother legally mother of child until adopted
| - Right to keep child so may decide doesn't want to give away
47
How many matches pairs of chromosomes are there in the body?
22, 23rd pair is XX or XY
48
What are males' 23rd chromosomes?
X + Y, controlling male characteristics
49
What are the females' 23rd chromosomes?
X + X, allowing female characteristics to develop
50
Which gamete is responsible for the gender to the offspring?
Sperm, can carry X or Y but egg can only carry X
51
What does it mean if a characteristic is sex-linked?
The allele that codes for it is on the sex chromosome (X or Y)
52
Which sex chromosome is smaller and what does this mean?
- Y chromosome is smaller than C chromosome
- Carries fewer genes
- Most genes on the sex chromosome are carried on X chromosome
53
Which gender are more likely to get sex-linked disorders and why?
- Men
- Only have one allele for sex linked disease (different sex chromosomes, XY)
- Even if recessive have it as no dominant to counteract (unlike women)
54
What is a sex-linked genetic disorder?
Disorders caused by faulty genes on the sex chromosomes
55
What are some examples of sex-linked genetic disorders?
- Colour blindness
| - Haemophilia (where sufferer's blood won't clot properly when cut themselves)
56
How does bacteria reproduce?
- Reproduce by splitting in 2
| - Growth is exponential (start with small number but grows quickly)
57
What did Louis Pasteur do?
- Showed microbes caused decay + disease
- Until 19th century, people though disease just appeared
- Showed microbes in air which cause disease/decomposition
58
What was the experiment Louis Pasteur did to show disease was caused by microbes?
- Heated broth in 2 flasks the left open
- One have curved neck so bacteria in air would settle in loop; not get through to broth
- This broth stayed fresh but other didn't
- Showed it was microbes in air causing it to go off
59
What is pasteurisation?
- Heating something to about 70⁰C then cooling it
| - Kills of most harmful germs so product shouldn't make you ill
60
What is an aseptic technique?
A process that reduces contamination by germs, like pasteurisation
61
When is pasteurisation used?
Treats milk to kill harmful bacteria, making it safe to drink
62
Why is pasteurisation preferred to sterilising?
Sterilisation kills everything, including some vitamins + makes milk taste funny
63
What is resazurin dye?
A dye sensitive to oxygen
64
What are the different colours of the Resazurin dye at different levels of oxygen?
```
Lots of oxygen
Blue
Lilac
Mauve
Pink
Colourless
Least oxygen
```
65
How can you used Resazurin dye to measure the microorganism numbers?
- Microorganisms use up oxygen (respiration)
- Lots of microorganisms = less oxygen = colourless dye
- Few microorganisms = more oxygen = blue dye
66
How could you test how different conditions affect the growth of bacteria?
- Pour 10cm3 fresh milk to 3 sterile test tubes; add 1cm3 Resazurin dye + mix
- Store different test tubes at different conditions (e.g. temp,, pH)
- Record colour change of dye at different time intervals
67
What happens when a microorganism enters the body?
Reproduces rapidly unless destroyed
68
What is the role of the immune system?
Kill harmful microorganisms that enter the body
69
What is the role of the white blood cells?
- Travel around body
| - Watch for microorganisms
70
What do B-lymphocytes do?
- Each pathogen has unique molecules on surface of cells, called antigens
- When B-lymphocytes come across foreign antigen produce proteins called antibodies
- Antibodies bind to + kill new invading cells
- Antibodies produced are specific to that pathogen; won't attack other pathogens
- Antibodies then produced rapidly + flow all round body to kill all similar bacteria/viruses
71
Why is the response slow when a pathogen enters the body for the first time?
There aren't many -B-lymphocytes that can make the antibody to lock on to the antigen
-Person will show symptoms of the disease
72
When are memory lymphocytes produced?
After first being exposed to an antigen
73
What do memory lymphocytes do?
- Remain in the body for a long time + remember a specific antibody
- Person now immune
74
What happens when a pathogen enters the body for the second time?
- Immune system will have a quicker response
| - Gets rid of pathogen before any symptoms show
75
Why do people get immunised?
Avoid getting ill by some diseases
76
How does immunisation work?
- Injecting dead/inactive microorganisms into body
- They're antigenic (carry antigens)
- So harmless but body still makes antibodies to attack them
- Antigens trigger memory lymphocytes to be made
- If live microorganisms (same type) appear after, killed immediately by already developed antibodies
77
Who invented the first vaccine and what did it immunise against?
Edward Jenner against smallpox
78
How did Edward Jenner create the first vaccine?
- Noticed those w/ cowpox (mild disease from cattle) didn't get smallpox
- 1796: took bits of scab from girl w/ cowpox, put into cut on arm of boy.
- Boy was unwell but recovered
- Jenner exposed boy to cowpox but didn't catch it
79
Why did Edward Jenner's vaccine work?
- Cowpox antigen triggered boy's B-lymphocytes to produce antibodies
- Smallpox has some same antigens as cowpox
- When infected by smallpox, immune system quickly made antibodies to stop him getting disease
80
What are the benefits of immunisation?
- Prevents epidemics if large % of population immunised. (Even those not immunised have reduced risk as less have disease)
- Some diseases virtually wiped out by immunisation e.g. smallpox
81
What are the drawbacks of immunisation?
- Doesn't always work
| - Although rarely, some have bad reaction to disease
82
What produces antibodies?
B-lymphocytes
83
How are monoclonal antibodies produced?
- B-lymphocytes not divide quickly but tumour cells do so can be grown easily
- Fuse B-lymphocyte + tumour cell to produce hybridoma cell
- Hybridoma cells divide quickly producing lots of identical antibodies called monoclonal antibodies
- Produce lots of antibodies against a certain antigen
84
How are monoclonal antibodies used in pregnancy tests?
- Hormone found in urine of only pregnant women which pregnancy test sticks detect
- Where you wee has antibodies to hormone w/ blue beads attached
- Test strip (turns blue if pregnant) has antibodies to hormone stuck on it (can't move)
- If pregnant: hormone binds to antibodies on blue beads; urine moves up stick, carrying hormone + beads; beads + hormone bind to antibodies on strip; blue beads stuck on strip, turning it blue
- If not pregnant: wee on stick; urine moves up stick w/ blue beads; nothing to stick blue beads to test strip so not blue
85
How can monoclonal antibodies be used to stick to cancer cells?
- Different cell have different antigens on surface so monoclonal antibodies made to stick to any
- Cancer cell have antigens on cell membrane not on normal body cells: tumour markers
- Monoclonal antibodies made to bind to tumour markers to help diagnose + treat cancer
86
How can monoclonal antibodies be used to diagnose cancer?
- Antibodies labelled w/ a radioactive element
- Labelled antibodies given to patient through a drip, into blood so carried around body
- When antibodies come into contact w/ cancer cells they bind to the tumour markers
- Pic of patient's body taken w/ special camera detecting radioactivity: cancer spots show w/ bright spot
- Doctors see where cancer is, size + see if spreading
87
How can monoclonal antibodies be used to target drugs to cancer cells?
- Anti-cancer drug attached to monoclonal antibody
- Antibodies given to patient through drip
- Antibodies target specific cells (cancer cells) as only bind to tumour markers
- Drug kills cancer cells but not normal cells near tumour
88
What are the benefits of using monoclonal antibodies to target drugs to cancer cells as opposed to other drugs or radiotherapy?
- Other drugs/radiotherapy kill normal cells
| - Lower side effects w/ monoclonal antibody treatment
89
How can monoclonal antibodies be used to find blood clots?
- When blood clots, proteins join together in blood forming solid mesh
- Monoclonal antibodies developed to bind to proteins
- Can attach radioactive element to antibodies
- Inject into body + take pics using camera that detects radiation, there'll be bright spot where blood clot is
- Can easily find potentially harmful blood clots
90
How do plants defend themselves against pests and pathogens?
Chemicals
91
What are some examples of plant chemicals being used as medicines?
- Aspirin
- Taxol
- Quinine
92
Where is aspirin from and what is it used for?
- Used to treat many type of pain + lower fever
| - Developed from chemical found in leaves + bark of willow tree
93
Where is Taxol from and what is it used for?
- Anti-cancer drug
- From bark of Pacific Yew tree
- Discovered when scientists screened plants for potential treatments
94
Where is Quinine from and what is it used for?
- From South American cinchona tree
| - Was the main treatment against malaria
95
What are the three main types of pests to crops?
- Insects
- Weeds
- Pathogens
96
How do insects (fruit flies) affect crop yield?
Feed on them so ruin entire fruit crops
97
How do weeds affect crop yield?
- When growing near plants take up nutrients from soil
| - Plant gets fewer nutrients = won't grow as well = lower yield
98
How do pathogens affect crop yield?
- Energy taken by pathogen/used to replace bits broken
- Less energy to make useful things e.g. fruit, so lower yield
- Heavy infestation = whole fields of plants produce no food at all
99
How do pests affect the cost of producing food?
- Increases
- Money spent on pesticides
- Disease-resistant/insect-resistant crops
100
How do pests affect consumers?
Lower crop yields increases the price for consumers
101
What is a photoperiodic response?
- Response to a change in amount of light + dark in 24 hour cycle
- Some plants germinate, grow or slower in certain amounts of light + dark to ensure they grow at time of year that best suits them
102
How do seeds of Arctic plants act as a photoperiodic response?
- Some only germinate when the fays are long
- So only germinate in middle of summer
- When temperatures are warmest
103
How do some plant buds act as a photoperiodic response?
- Use increasing day length to know it's far enough from winter to start to grow
- So don't sprout + get killed by frost
104
How do long-day plants and short-day plants act as a photoperiodic response?
- Long-day: only flower when days at least certain length (near midsummer)
- Short-day: only slower when days less than certain length (early spring/autumn)
- So only right insect are about to pollinate flowers
105
What is a circadian rhythm?
Biological processes that follow a 24 hour period
106
What types of circadian rhythms are there?
- Chemical patterns
- Physiological patterns
- Patterns of behaviour
107
How are circadian rhythms controlled?
Controlled internally but affected by environmental facts (e.g. light intensity)
108
What are some circadian rhythms in animals?
- Sleep patterns
| - Urine production
109
What is the body's master clock?
A group of nerve cells in the brain
110
What does animal's sleep pattern follow a circadian rhythm?
- Body's master clock gets info of light intensity from eyes
- Controls production of melatonin (which makes you tired)
- When dark: melatonin production increases (opposite in nocturnal animals)
- Regular sleep patterns = good for health + feel awake at right times
111
How does animal's urine production follow a circadian rhythm?
- Body's master clock controls ADH production
- At night ADH level increases
- Reduces urine production (so sleep not interrupted)
112
What are some circadian rhythms in plants?
- Stomata opening
| - Flower opening
113
How does the stomata opening in plants follow a circadian rhythm?
- Stomata respond to light intensity
- Open in day + close at night
- During day photosynthesis occurs; stomata open so CO2 in + O2 out
- Night: photosynthesis stops so stomata closes reducing water loss
114
How does the flower opening in plants follow a circadian rhythm?
- Respond to light intensity by opening/closing flowers at different times of day
- Only need to be open when created that pollinate them are active
