Weaknesses: Flashcards
1
Q
Define active transport
A
The movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy.
2
Q
What is the test for lipids?
A
Emulsion test
Clear to milky white
3
Q
What is the test for sugars?
A
Benedict’s test
Colour change of blue to brick-red
4
Q
What is the role of the liver in terms of respiration?
A
The liver is where lactic acid is broken down
5
Q
What is radiotherapy?
A
When cancer cells are destroyed by concentrated doses of radiation
6
Q
What 5 defences do plants have to disease/herbivores?
A
Poisons Thorns Hairy stems Drooping leaves Mimicry
7
Q
What is gonorrhoea?
A
A bacterial STD. Symptoms include a green discharge.
8
Q
How are capillaries adapted?
A
- One cell thick
- Carry blood very close to cells
- Permeable walls
9
Q
How does the heart work?
A
1) deoxygenated blood flows into the right atrium via the vena cava
2) the right atrium contracts forcing the blood into the right ventricle, through a tricuspid valve
3) the ventricle contracts, forcing the blood into the pulmonary artery. From here, the deoxygenated blood goes to the lungs
4) at the same time, oxygenated blood is returning from the pulmonary vein into the left atrium.
5) the atrium contracts, forcing the blood through a bicuspid valve into the left ventricle.
6) the ventricle contracts, meaning blood is pushed into the aorta from which it is circulated
10
Q
What is an independent variable?
A
The thing being tested
11
Q
What is the test for proteins?
A
The biuret test
Blue to pink or purple
12
Q
What does a stent do?
A
It pushes the artery wall out, squashing fatty deposits.
13
Q
What 4 ways can society help stop the spread of antibiotic resistant bacteria?
A
- Complete courses
- Don’t over-prescribe
- Don’t give animals too much antibiotics
- Don’t ask for antibiotics
14
Q
What is Tobacco Mosaic Virus?
A
A virus that effects plants. It causes plants to be discoloured so they cant photosynthesise.
15
Q
How are veins adapted?
A
- Bigger lumen
- Thinner walls
- Valves
16
Q
What is the equation for anaerobic respiration?
A
Glucose = lactic acid + energy
17
Q
What is the role and adaptation of the palisade layer?
A
Where most photosynthesis takes place. Has lots of chloroplasts.
18
Q
What are the stages of how a pregnancy test works?
A
1) urine passes through reaction zone
2) HCG (hormone in urine) binds to mobile HCG antibody which is connected to the blue dye
3) HCG moves up the stick and binds to immobile HCG antibodies in result zone
4) other antibodies which do not bing to HCG bind to antibodies in control zone
5) blue dye appears in both zones
19
Q
What do proteases do?
A
They convert proteins into amino acids
20
Q
Why do multicellular organisms need exchange surfaces?
A
They have a smaller surface area : volume ratio
21
Q
What is a prokaryote?
A
A cell that doesn’t have a true nucleus
22
Q
How are the alveoli adapted for gas exchange?
A
- Large SA
- Moist lining
- Thin walls
- Good blood supply
23
Q
Define differentiation
A
The process by which a cell changes to become specialised for its job
24
Q
Where is amylase made?
A
- Salivary glands
- Pancreas
- Small intestine
25
What is Malaria?
A disease caused by a protist. It causes repeating episodes of fever. It is spread by the vector, mosquitos.
26
How do enzymes work?
The active site of an enzyme will only fit to one substrate
The substrate fits into and binds to the enzyme
The enzyme breaks it down and releases the products
The enzyme does not get used up so can be used in other reactions
27
Where are proteases made?
- Stomach (pepsin)
- Pancreas
- Small intestine
28
Where did digitalis come from?
A chemical found in foxgloves
29
How do you make monoclonal antibodies?
1) Mouse injected with antigen
2) Fuse mouse lymphocyte with a tumour cell to create a hybridoma
3) Hybridoma clone to get lots of identical cells.
4) Collect and purify the antibodies
30
What is the effect of drinking alcohol whilst pregnant?
The alcohol passes through the placenta into the baby. It can lead to miscarriages and deformities.
31
Define osmosis
The movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration
32
How are root hair cells specialised?
Big surface area
Thin walls
Lots of mitochondria to produce energy for active transport
33
What is the role and adaptation of the stomata?
Lets CO2 diffuse directly into the leaf. Controlled by guard cells to respond to changes in environment.
34
What is the equation for aerobic respiration?
C6H1206 + 6O2 = 6CO2 + 6H20 + energy
35
What is the formula for light intensity?
1/d^2
36
What is the oxygen debt?
The amount of oxygen required to turn the lactic acid into carbon dioxide and water
37
How big are prokaryotic cells generally?
0.2-2nm
38
What is salmonella?
A bacterial disease which causes fever, stomach cramps, vomiting and diarrhoea. It is caused by eating food that had the disease when it was alive.
39
What are the 3 main ways that pathogens can be spread?
- Water
- Air
- Contact
40
What is a causal mechanism?
Something that explains how one factor effects another
41
If the concentration of solutes is lower inside the cell than in the solution, what is the solution called?
Hypertonic
42
What is the role of the nucleus?
Contains genetic information
43
How does smoking effect the heart?
Smoking narrows blood vessels. Nicotine increases heart rate and the chemicals in tobacco lead to increased blood pressure. All together, these lead to an increased chance of heart disease.
44
What is the test for Starch?
Iodine solution
| Browny-orange to black or dark blue
45
Where is bile stored and made?
Stored in gallbladder and made in liver
46
What do carbohydrases do?
They convert carbohydrates into simple sugars
47
Where are lipases made?
- Pancreas
| - Small intestine
48
What is the role and adaptation of the spongy mesophyll?
Where gas exchange take place. Has big air spaces to allow gases to diffuse.
49
What is a dependent variable?
The thing being measured
50
How are sperm cells specialised?
They have a long tail
Streamlined head
Lots of mitochondria for respiration
Carries enzymes to help digest through the egg's membrane
51
What is a eukaryote?
An organism made up of more complex cells (e.g plant or animal cells)
52
What does a lack of magnesium ions cause?
Plant will suffer from chlorosis and have yellow leaves
53
What is the role and adaptation of the upper epidermis?
To cover the plant. Transparent so that light can reach the palisade layer
54
Give an example of a antibiotic resistant bacterium
MRSA causes serious wound infections and is resistant to meticillin.
55
What is the role of the cytoplasm?
Where chemical reactions take place
56
What is the role of the large intestine?
To absorb any water from the food.
57
Name 5 adaptations of the circulatory system
- dual circulatory system means blood is pumped at higher pressure
- heart made of cardiac muscle to allow contractions
- haemoglobin have no nucleus for maximum oxygen can be carried
- thin walls for easy diffusion
- large surface are of capillaries to maximise gas exchange
- cardiac output is effected by adrenaline
- veins have valves to stop back flow
58
What is chemotherapy?
When chemicals are used to stop the spread of make the cancer cells 'self-destruct'
59
What is Rose Black Spot?
A fungal disease that causes black spot on leaves of rose plants. They can be spread in the wind on in water.
60
How does cancer spread?
The original tumour breaks off into secondary tumour. It is then spread to other organs via the blood.
61
Why is smoking especially a problem for pregnant women?
They need to carry oxygen for both themselves and their babies, when some of this oxygen is replaced by carbon monoxide, it can lead to premature births.
62
How to viruses reproduce?
1) Virus injects its DNA into cell
2) It uses to host cell to replicate
3) Cell explodes releasing more of the same virus
63
What is the role of mitochondria?
To carry out respiration
64
What is the role of the small intestine?
The main function of the small intestine is absorption of nutrients and minerals from food.
65
What is measles?
A viral disease spread in the air. Symptoms include a rash, and a fever. You can be vaccinated against it.
66
What do lipases do?
They convert lipids into glycerol and fatty acids
67
What are the stages of binary fission?
1) The bacterium copy it’s DNA and plasmid(s)
2) The bacterium elongates and the copies of DNA are separated
3) The cell divides (cytokinesis)
4) Each cell is now a separate daughter cell
68
What is the equation for anaerobic respiration in plants?
Glucose = ethanol + CO2
69
How big are eukaryotic cells generally?
10-100nm
70
When do guard cells close the stomata?
When water levels are low
71
What is the role and adaptation of the Phloem?
Transports food substances (mainly sugars). Has small pores to allow cell sap to flow through.
72
How can we measure the rate of photosynthesis?
1) A source of light is placed at a specific distance from pond weed, which is in a test tube connected to a gas syringe.
2) The pond weed is left to photosynthesise for a set amount of time.
3) The oxygen released will collect in the gas syringe
4) Repeat at the same distance and calculate a mean
5) Complete at different distances to find results
This could be swapped for apparatus to test effects of temperature and CO2 levels (water bath or dissolving sodium hydrocarbonate)
73
What is the role of the chloroplasts?
Where photosynthesis takes place
74
What are the similarities of light and electron microscopes?
Similarities:
- Both magnify an image
- Both used in scientific research
Differences:
- Electron microscopes use electrons instead of light to form an image
- Electron microscopes have a higher resolution
- Light microscopes are mobile
- Light microscopes are cheaper
- Electron electroscopes have a higher magnification
75
What is the role and adaptation of the Xylem?
Carry water and mineral ions from the roots to the stem and leaves. Strengthened by lignin.
76
If the concentration of solutes is higher inside the cell than in the solution, what is the solution called?
Hypotonic
77
In what 5 ways do plants use cellulose?
- Respiration
- Making cellulose
- Making amino acid
- Stored as oils and fats
- Stored as starch
78
What is the role of the cell wall?
Supports and strengthens cells (made of cellulose)
79
What do nitrate ions, phosphate ions and potassium ions do for plants?
Nitrate - growth
Phosphate - flowering or fruits
Potassium - strong roots
80
If the concentration of solutes is equal inside the cell and in the solution, what is the solution called?
Isotonic
81
What is the role of the ribosomes?
Where proteins are made
82
How are arteries adapted?
- Artery walls are strong and elastic
- Thick walls
- Narrow lumen
83
How are muscle cells specialised?
Cells are long so that they have space to contract
| Lots of mitochondria
84
What does a lack of nitrate ions cause?
Stunted growth
85
What is HIV?
A virus spread by sexual contact. Flu-like symptoms.
86
What are the stages of drug testing?
Pre-clinical trial:
Test on animals to test toxicity, dosage and efficacy
Clinical trial:
Test in healthy volunteers as very low dosage to monitor for side effects
Do trials for optimum dosage
Use of placebo
Peer review of data
87
What is the role of the cell membrane?
Controls what goes in and out
88
What is the role of the mitochondria?
Where most reactions for aerobic respiration take place
89
How are nerve cells specialised?
Cells are very long
| Branched connections to connect to other nerve cells to form a network
90
What it the process of moving food to a plants leaves?
Translocation
91
How are gills adapted for gas exchange?
Water enters the fish through its mouth and passes out through the gills. As this happens, oxygen diffuses out of the water into the blood and CO2 does the reverse. Each gill has lots of gill filaments to increase the surface are for gas exchange. Gill filaments have lamellae which increase the SA further
92
What are the two roles of bile?
To neutralise stomach acid
| To emulsify lipids
93
What is the role of villi?
Villi increase surface are for the absorption of nutrients in the small intestine
94
Define diffusion
The spreading out of particles from an area of higher concentration to an area of lower concentration
95
What 4 things effect transpiration rate?
Light intensity - the brighter, the greater the rate
Temperature - the warmer the faster the rate
Air flow - the better the air flow, the faster the rate
Humidity - the drier the faster the rate
96
How do you prepare an onion cells to be used for magnification?
1) Add a drop of water to a clean slide
2) Cut an onion and use tweezers to peel of some epidermal tissue
3) Place the tissue onto the water
4) Add a drop of iodine solution to stain the objects
5) Place a cover slip on top whilst trying to avoid air bubbles.
97
What is the effect of tar in tobacco?
Tar leads to a break down of the alveoli which leads to breathlessness and death
98
What are the phases of mitosis?
Interphase - the DNA copies itself preparing for mitosis
Prophase - DNA condensed to become more visible
Metaphase - Chromosomes and copies line up in the middle of the cell
Anaphase - Chromosomes and copies are pulled to different ends of the cell
Telophase - New membranes form at each end of the cell
Cytokinesis - The cell membrane divides into two daughter cells
99
Where did aspirin come from?
A chemical found in willow
100
What is the role of the permanent vacuole?
Contains cell sap
