Mock March 2020 Flashcards
1
Q
Transpiration
A
. Movement of water . From the root through the plant . Through lignified cells dead cells . Of xylem . Driven by evaporation of water . From the leaves . Through the stomata . Flow is only in one direction . By capillary action . According to cohesion - tension theory
2
Q
Translocation
A
. Movement of sugars from the leaves . As sucrose . Through living sieve cells . Flow is bidirectional . To sinks in the plant where the sucrose is needed
3
Q
Inside the leaf top to bottom
A
Waxy cuticle Upper epidermis Palisade mesophyll Air space Spongy mesophyll Lower epidermis Waxy cuticle Guard cells with chloroplasts Exchange of gases through stomata
4
Q
Epidermis
A
Thin transparent
Allows light to reach palisade cells
5
Q
Thin cuticle made of wax
A
Protects leaf from infection and prevent loss without blocking out light
6
Q
Palisade cell
A
Top of leaf
Absorbs more light and increase rate of photosynthesis
7
Q
Spongy layer
A
Air spaces allows arson dioxide to diffuse through the leaf
8
Q
Chloroplast
A
Found in palisade layer to absorb available light
9
Q
Stomata
A
Allows CO2 to diffuse into the leaf and allow oxygen to diffuse out
Guard cells control opening and closing
Guard cells take in water by osmosis
10
Q
Osmosis
A
Diffusion of water molecules, from a region where they are in higher concentration, to a region where they are in lower concentratio
11
Q
Diffusion
A
will move in both directions, but there will be a net movement from high to low concentration
will end up evenly spread throughout the liquid or gas but will continue to move
12
Q
Reducing sugar
A
. Benedict’s
. Add Benedict’s reagent to the food and boil in a water bath
. Initial colour - blue
. Positive result - brick red precipitate
13
Q
Starch
A
. Iodine
. Add iodine reagent to food
. Initial colour - yellow/brown
. Colour of positive result blue-black
14
Q
Protein/amino acids
A
. Biuret (a mixture of sodium hydroxide and copper sulphate)
. Add Biuret reagent to the food
. Initial colour - blue
. Positive result - lilac/purple
15
Q
Fat
A
Ethanol
Add ethanol to the food to dissolve the fat then add water
Initial colour - colourless
Positive result - white emulsion
16
Q
Fick’s law
A
Rate of diffusion is proportional to surface area x concentration difference / thickness of membrane
17
Q
As surface area increases diffusion…
A
Increases
18
Q
As concentration difference increases
A
Rate of diffusion increases
19
Q
As membrane thickness increases rate of diffusion
A
Decreases
20
Q
10nm
20nm
A
x2
So
2000 x 1/2 = 1000
21
Q
10nm
5nm
A
X0.5
So
2000x1/0.5=4000
22
Q
10nm
0.016um
A
0.016um = 16nm
X 1.6
So
2000 x 1/1.6 = 1250
23
Q
Thermoregulation
A
Control of the internal body temperature in warm blooded animals. 37 degrees for humans.
24
Q
thermoregulatory centre
A
Contained in the hypothalamus in the brain, and it contains receptors sensitive to the temperature of the blood.
25
Too hot
. Sweat glands release sweat onto skin. The sweat evaporates, transferring heat energy from the skin to the environment.
. Vasodilation - blood vessels get wider increasing blood flow near skin surface
. Blood flow in skin capillaries increases
26
Too cold
. Shivering releases heat from respiration
. Subantaneous fat insulates
. Hairs stand up trapping insulators layer of air
. Vasoconstriction- blood vessels get narrower reducing blood flow near skin surface
27
Type 1 diabetes
. Pancreas cells cannot produce insulin because they have been destroyed by the immune system.
. Blood glucose levels increase and can be found in urine
. Treatment = inject with insulin just before eating to convert glucose to glycogen
28
Type 2 diabetes
. Caused by insulin releasing cells not producing enough insulin or target organs not responding to hormone
. Change in diet/exercise helps
Medicine needed
29
Blood Glucose Control (Insulin/Glucagon)
In blood glucose regulation - insulin. When blood sugar rises in the blood, insulin sends a signal to the liver, muscles and other cells to store the excess glucose. Some is stored as body fat and other is stored as glycogen in the liver and muscles. Whereas, if the blood glucose level is too low, the liver receives a message to release some of that stored glucose into the blood. This change is brought about by another hormone produced by the pancreas called glucagon.
This is an example of negative feedback.
30
Urinary system function
Removes excess amounts of some substances from blood including water and mineral salts. Removes waster products e.g. urea
31
Urea
Poisonous
| Passes into blood and kidneys filter it out
32
Osmoregulation
If conc of fluids change in body it causes water to move by osmosis. Osmosregulatio controls water and salt levels
33
Kidney function
. They regulate the water content in the blood
| . They excrete/remove the toxic waste products of metabolism
34
Excretory system
1. Blood is brought to the kidney in the renal artery which branches off the aorta.
2. The kidney regulates/controls the water and salt content and removes urea.
3. The filtered excess water, salts and urea form a liquid called urine.
4. The urine is transported to the bladder along tubes called ureters.
5. The bladder stores the urine until it is convenient to expel it from the body through the urethra.
6. The purified blood returns to the circulation through the renal vein and to the heart through the vena cava.
35
Kidney parts
```
. Cortex
. Medulla
. Pelvis
. Renal artery
. Renal vein
. Ureter
```
36
Nephron
Start in the cortex of the kidney and loop down into the medulla and back to the cortex.
The nephron regulates the level of water, and salts and removes urea from the blood.
37
Bowman’s capsule
surrounds a ball of capillaries called the capillary knot
high pressure is created in the capillary knot by the diameter of the capillary leaving the knot being narrower than the capillary entering
this pressure results in ultrafiltration where water, salts, glucose, and other small molecules pass out of the capillary and into the Bowman's capsule
proteins and blood cells are too big to leave the capillaries to go into the tubule
38
Collecting duct
selective reabsorption of water and for sending urine to the ureter
39
Kidney disease
The glucose levels in the blood are so high the kidney is unable to reabsorb it and it leaves the body in urine.
Protein in the urine indicates damage in the kidney, as generally proteins in the blood are too large to pass through into the nephron tubule.
40
Dialysis
1. Blood is removed from the patient and flows into the dialyzer where it is kept separated from dialysis fluid by a partially permeable membrane.
2. The dialysis fluid contains the same concentration of glucose and salts as normal blood plasma so there is no net movement of glucose out of the blood by diffusion.
3. Excess salts diffuse into the dialysis fluid.
4. The dialysis fluid contains no urea, so all of the urea diffuses from the blood in to the dialysis fluid from the high concentration in the blood to the lower concentration in the dialysis fluid.
5. The blood and dialysis fluid move in opposite directions across the membrane (a counter current system) in order to maintain concentration gradients all the way along.
The clean blood is returned to the patient and the waste dialysis fluid is disposed of.
41
Menstrual cycle
1-5: uterus lining breakdown and is lost with the unfertilised egg cell
10: menstruation ends and lining starts to thicken again
14: ovulation - ovary releases egg
16-21: fertilisation leading to pregnancy most likely
21: Uterus lining continues to thicken
23-28: egg cell travels along the oviduct to the uterus
42
FSH
. Follicle stimulating hormone
. Pituitary gland
. Causes an egg to mature in an ovary; stimulates the ovaries to release oestrogen
43
Oestrogen
. Ovaries
. Stops FSH being produced (so that only one egg matures in a cycle); repairs, thickens and maintains the uterus lining; stimulates the pituitary gland to release LH
44
LH
. Luteinising hormone
. Pit Ugarit are gland
. Triggers ovulation (the release of a mature egg)
45
Progesterone
. Ovaries
| . Maintains the lining of the uterus during the middle part of the menstrual cycle and during pregnancy
46
Describe the relationship between the different hormones during the 28 days
Days 1 to 12 - oestrogen gradually increases and peaks approximately on the 12th day. Progesterone, LH and FSH stay approximately at the same levels and begin to increase slightly from around day 12.
FSH and LH patterns are very similar and peak during ovulation at approximately 14 days during this cycle. They drop sharply on day 15 and stay constant until day 28.
Oestrogen drops during days 13 and 14, and progesterone continues to gradually increase until about day 21, when it slowly beings to decrease again. Oestrogen mirrors this shape and also has a second lower peak at about day 21
47
Hormones during the cycle
1. Low progesterone triggers release of FSH
2. Stimulates growth and maturation of egg follicle
3. Maturation stimulates oestrogen production
4. Oestrogen stimulates LH production and controls the thickening of uterus lining
5. LH triggers ovulation (release of egg into oviduct from follicle I’m ovary
6. The remains of the follicle (corpus leteum) releases progesterone
7. Progesterone inhibits LH and FSH
8. Low levels of progesterone and oestrogen (due to no corpus let or mature egg leads to menstruation, back to start
48
Alveoli
they give the lungs a really big surface area
they have moist, thin walls (just one cell thick)
they have a lot of tiny blood vessels called capillaries
Alveoli are adapted to make gas exchange in lungs happen easily and efficientl
49
Respiration practical
.Assemble the respirometer like the diagram, check that you know how to use it, especially the operation of the three way tap. Clamp the syringe and the respirometer in position when in use
2.Place as known mass of one type of organsm into the boiling tube. For our experiment we used 10 maggots, it is still accurate to use a quantity as the maggots were generally uniform in size so the mass would have been similar. Handle live animals with care to avoid harming them]
3. Place a drop of coloured fluid at the open end of the glass tube using the dropping pipette. Open the connection between the syringe and the respirometer. Use the syringe to draw the fluid onto the scale at the end furthest from the respirometer
4. Mark the starting position of the fluid
5. Close the tap to isolate the respirometer from the atmosphere and the syringe and start the stop clock immediately
6. Note the position of the fluid at one minute intervals for at least five minutes
7. Work out the distance travelled by the liquid during each minute. Record your results in a suitable table.
50
Aerobic respiration
. Oxygen present
. Releases more energy
. Produces carbon dioxide, water and energy
. Glucose completely broken down
. Occurs in mitochondria
Glucose + oxygen —> carbon dioxide + water + energy
51
Anaerobic respiration
```
. Occurs in cytoplasm
. Oxygen absent
. Releases less energy
. Glucose not completely broken down
. Produces lactic acid and energy (muscle cells) or ethanol, carbon dioxide and energy (yeast)
Glucose —> lactic acid
```
52
High blood sugar
. Brain selects the level off glucose in the blood
. Increased blood glucose
. Pancreas is stimulated to release insulin
. Insulin goes to liver
. The level of glucose in the blood decreases, causing the pancreas to stop producing insulin
. Blood glucose returns to normal
53
Low blood sugar
. Decreased blood glucose
. Glycogen goes to liver
. The level of glucose in the blood increases, causing the pancreas to stop producing glycogen
. Blood glucose returns to normal
54
Non-hormonal contraception
. physical barrier methods such as condoms and diaphragms, which prevent the sperm reaching an egg
. intrauterine devices (IUD) also known as a coil, prevent the implantation of an embryo or release of a hormone
. spermicidal agents which kill or disable sperm
. abstaining from intercourse when an egg may be in the oviduct
. surgical methods of male and female sterilisation, eg a vasectomy, where the sperm ducts are cut and tied
55
Hormonal contraception
The oral contraceptive, which is known as the pill, contains oestrogen or progesterone. These hormones prevent the production of FSH, so eggs cannot mature.
56
Arteries
. Carry oxygenated blood away from the heart
| . Thick walls to cope with high blood pressure
57
Venus
. Carry deoxygenated blood back to heart
| . Don’t need thick walls as the blood flows slowly
58
Capillaries
. Walls are 1 cell thick
. Connect arteries and veins
. Carry blood through tissues and organs
59
Heart directions
The right-hand side of the heart is responsible for pumping deoxygenated blood to the lungs.
The left-hand side pumps oxygenated blood around the body.
60
Atria
The atria (plural of atrium) are where the blood collects when it enters the heart.
61
Septum
The septum separates the right-hand and left-hand side of the heart.
62
tricuspid valve
The tricuspid valve is located between the right atrium and right ventricle and opens due to a build-up of pressure in the right atrium.
63
bicuspid valve
The bicuspid valve is located between the left atrium and left ventricle and likewise opens due to a build-up of pressure, this time in the left atrium.
64
semilunar valves
The semilunar valves stop the back flow of blood into the heart. There is a semilunar valve where the aorta leaves the left ventricle and another where the pulmonary artery leaves the right ventricle.
65
aorta
The aorta is the largest artery in the body. It carries oxygenated blood away from the left ventricle to the body.
66
vena cava
The vena cava is the largest vein in the body. It carries deoxygenated blood from the body back to the heart.
67
pulmonary artery
The pulmonary artery carries deoxygenated blood away from the right ventricle to the lungs.
68
pulmonary vein
The pulmonary vein returns oxygenated blood from the lungs to the heart.
69
Left-hand side
Oxygenated blood is carried to the heart from the lungs in the pulmonary vein. It goes into the left atrium, through the bicuspid valve and into the left ventricle. The ventricle pumps the blood through the semilunar valve, into the aorta and round the body.
70
Right-hand side
Deoxygenated blood from the body is carried to the heart in the vena cava. It goes into the right atrium, through the tricuspid valve and into the right ventricle. The ventricle pumps the blood through the semilunar valve, into the pulmonary artery and to the lungs.
71
Cardiac output
```
Volume of blood pushed into aorta each minute
Cardiacs output (litres/mis) = stroke volume (litres/beat) x heart rate (beats/min)
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