Biology paper 1 Flashcards
(147 cards)
1
Q
Cells -
Contains genetic information that controls the functions of the cell.
A
Nucleus
2
Q
Cells -
Controls what enters and leaves the nucleus.
A
Cell membrane
3
Q
Cells -
Where many cell activities and chemical reactions in the cell occur.
A
Cytoplasm
4
Q
Cells -
Provides energy from aerobic respiration
A
Mitochondria
5
Q
Cells -
Synthesis (makes) proteins
A
Ribosome
6
Q
Cells -
Where photosynthesis occurs
A
Chloroplast
7
Q
Cells -
Used to store water and other chemicals as cell sap
A
Permanent vacuole
8
Q
Cells -
Strengthens and supports the cell. (Made of cellulose in plants).
A
Cell wall
9
Q
Cells -
A loop of DNA, not enclosed within a nucleus.
A
DNA loop
10
Q
Cells -
A small circle of DNA, may contain genes associated with antibiotic resistance.
A
Plasmid
11
Q
Cells -
Acrosome contains enzymes to break into egg; tail to swim; many mitochondria to provide energy to swim.
A
Sperm cell
12
Q
Cells -
Long to transmit electrical impulses over a distance.
A
Nerve cell
13
Q
Cells -
Contain protein fibres that can contract when energy is available, making the cells shorter.
A
Muscle cell
14
Q
Cells -
Waterproofed cell wall; cells are hollow to allow water to move through.
A
Xylem cell
15
Q
Cells -
Some cells have lots of mitochondria for active transport; some cells have very little cytoplasm for sugars to move through easily.
A
Phloem cell
16
Q
Cells -
Long extension to increase surface area for water and mineral uptake; thin cell wall.
A
Root hair cell
17
Q
Cells -
Contains: cytoplasm, nucleus, ribosome, mitochondria and cell membrane.
A
Animal cell
18
Q
Cells -
Contains: cytoplasm, nucleus, ribosome, mitochondria, cell membrane, chloroplast, vacuole and cell wall.
A
Plant cell
19
Q
Microscopy -
The degree by which an object is enlarged
A
Magnification
20
Q
Microscopy -
The ability of a microscope to distinguish detail.
A
Resolution
21
Q
Microscopy -
Basic microscope with a maximum magnification of 1500x. Low resolution.
A
Light microscope
22
Q
Microscopy -
Microscope with a much higher magnification and resolving power than a light microscope. This means that it can be used to study cells in much finer detail.
A
Electron microscope
23
Q
Mitosis and the cell cycle
A
- Number of sub-cellular structures increase
- Number of chromosomes double
- One set of chromosomes is pulled to each end of the cell
- The nucleus divides
- Cytoplasm and cell membranes divide to form two identical cells
24
Q
Stem cells -
Can divide into most types of cells
Used for therapeutic cloning
A
Embryonic stem cells
25
Stem cells -
| Can divide into a limited number of cells
Adult stem cell
26
Stem cells -
Found in plants
Can differentiate (divide) into any type of plant cell
Meristem
27
Pros of using stem cells
Treatment of diseases such as diabetes, dementia and paralysis
28
Cons of using stem cells
Ethical and religious objections
| Can transfer viruses held within cells
29
Transport across membranes -
| Diffusion definition
Spreading out of the particles resulting in a net movement from an area of higher concentration to an area of lower concentration
30
Transport across membranes -
| Diffusion use
Oxygen and carbon dioxide in gas exchange (leaves and alveoli)
Urea from cells into the blood plasma for excretion in the kidney
31
Transport across membranes -
| Osmosis definition
The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.
32
Transport across membranes -
| Osmosis use
Movement of water into and out of cells
33
Transport across membranes -
| Active transport definition
The movement of substances from a more dilute solution to a more concentrated solution. Requires energy from respiration.
34
Transport across membranes -
| Active transport use
Absorption of mineral ions (low concentration) from soil into plant roots. Absorption of sugar molecules from lower concentration in the gut into the blood which has a higher sugar concentration.
35
Factors affecting diffusion -
| Difference in concentrations explanation
The greater the difference in concentrations, the faster the rate of diffusion.
36
Factors affecting diffusion -
| Temperature explanation
Particles move more quickly at higher temperatures, so rate of diffusion increases.
37
Factors affecting diffusion -
| Surface area of membrane explanation
The greater the surface area the quicker the rate of diffusion.
38
Adaptation of exchange surfaces
- Large surface area
- Thin membrane (provides short diffusion path)
- Ventilation (in animals for gas exchange - maintains a concentration gradient)
- Efficient blood supply (in animals - maintains a concentration gradient
39
Organisation -
| Tissue
A group of cells with a similar structure and function
| muscle, tissue
40
Organisation -
| Organ
A group of tissues performing a specific function
| heart, leaf
41
Organisation -
| Organ system
A group of organs that perform a specific function (digestive system)
42
Enzymes key terms -
| Enzyme
A biological catalyst that can speed up the rate of reaction without being used itself. Made of a large protein molecule.
43
Enzymes key terms -
| Substrate
The chemical that fits into the active site of an enzyme
44
Enzymes key terms -
| Lock and key model
Only one type of substance can fit into the active site of an enzyme, like a key fits into a lock.
45
Enzymes key terms -
| Denatured
When the active site of an enzyme changes shape and the substrate can no longer fit in. Can be caused by pH or temperature.
46
Testing for biological molecules -
| Starch chemical test
Add orange/brown iodine solution
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Testing for biological molecules -
| Starch positive result
Colour turns blue/black
48
Testing for biological molecules -
| Sugar chemical test
Add blue Benedict's solution. Place in a boiling water bath for 5 minutes
49
Testing for biological molecules -
| Sugar positive result
Colour turns green / yellow / orange / brick red
50
Testing for biological molecules -
| Protein chemical test
Add blue Biuret solution
51
Testing for biological molecules -
| Protein positive result
Colour turns lilac/purple
52
Testing for biological molecules -
| Lipid chemical test
Add ethanol and decant into water
53
Testing for biological molecules -
| Lipid positive result
Cloudy white emulsion
54
Human digestive enzymes -
| Amylase
Function - breaks starch into sugars
Sites of production - salivary glands, pancreas, small intestine
Sites of action - mouth, small intestine
55
Human digestive enzymes -
| Protease
Function - breaks proteins into amino acids
Sites of production - stomach, pancreas, small intestine
Sites of action - stomach, small intestine
56
Human digestive enzymes -
| Lipase
Function - breaks lipids (fats) into fatty acids and glycerol
Sites of production - pancreas, small intestine
Sites of action - small intestine
57
Other chemicals -
| Hydrochloric acid
Acid with pH produced by the stomach. Unravels proteins.
58
Other chemicals -
| Bile
Emmulsifies fats (turns them into droplets to give a greater surface area). It is alkaline so neutralises acids from the stomach. Produces in liver, stored in gall bladder and is released into the small intestine.
59
Structures in the heart -
| Pacemaker
Group of cells in the right atrium that controls resting heart rate.
60
Structures in the heart -
| Right ventricle
Pumps deoxygenated blood to the lungs for gas exchange.
61
Structures in the heart -
| Left ventricle
Pumps oxygenated blood to the body. Thick, muscular wall.
62
Structures in the heart -
| Valve
Stops blood flowing the wrong way / leaking.
63
Structures in the lungs -
| Alveoli
Small sacs where gas exchange occurs. Surrounded by capillaries. Oxygen moves from the alveoli into the capillaries, carbon dioxide moves from the capillaries into the alveoli.
64
Structures in the lungs -
| Trachea and Bronchi
Tubes through which gases move. Lined with cartalige so they don't collapse.
65
Heart disease -
| Coronary heart disease
Build up of fatty material in coronary arteries. Can lead to a blood clot and a heart attack.
66
Heart disease treatment -
| Stent
What - wire mesh that opens up a blocked artery
Advantage - keeps artery open, low risk of surgery
Disadvantage - fatty materials can rebuild
67
Heart disease treatment -
| Statin
What - drug that reduces cholesterol
Advantage - reduces fat being deposited in arteries
Disadvantage - side effects (liver damage)
68
Heart disease treatment -
| Heart transplant
What - replacement heart from a donor
Advantage - long-term
Disadvantage - major surgery, could be rejected
69
Heart disease treatment -
| Artificial heart
What - man-made heart used while waiting for transplant
Advantage - not rejected, keeps patient alive
Disadvantage - short life time, battery has to be transported, limited activity
70
Heart disease treatment -
| Mechanical heart valve
What - mechanical replacement of faulty heart valve
Advantage - can last a life-time
Disadvantage - can damage red blood cells
71
Heart disease treatment -
| Biological heart valve
What - biological replacement of faulty heart valve
Advantage - don't damage red blood cells
Disadvantage - valve hardens and may need replacing
72
Blood vessels -
| Artery
Purpose - takes blood away from the heart
| Adaptation - thick wall to withstand high pressure
73
Blood vessels -
| Vein
Purpose - takes blood back the the heart
| Adaptation - thin wall. Valves to prevent backflow of blood.
74
Blood vessels -
| Capillary
Purpose - exchange of substances between blood and cells
| Adaptation - wall is one cell thick to allow quick diffusion of substances
75
Components of the blood -
| Plasma
Liquid part of the blood. Transport blood cells as well as carbon dioxide, proteins, glucose, hormones and urea.
76
Components of the blood -
| Red blood cells
Carries oxygen. Packed with haemoglobin, a protein that blinds to oxygen. No nucleus to create extra space for haemoglobin. Biconcave shape to give a large surface area.
77
Components of the blood -
| White blood cells
Destroys pathogens. Some can produce antibodies.
78
Components of the blood -
| Platelets
Cell fragments that help to clot wounds.
79
Movement within plants -
| Transpiration
The loss of water vapour from the leaves by evaporation from cells and then out through the stomata.
80
Movement within plants -
| Transpiration stream
The movement of water from the roots, up the steam to the leaves.
81
Movement within plants -
| Translocation
The movement of dissolved sugars around the plant
82
Factors affecting transpiration -
| Temperature
Increasing temperature increases the transpiration rate as water evaporates quickly.
83
Factors affecting transpiration -
| Humidity
Increasing humidity decreases the rate of transpiration as water evaporates slowly.
84
Factors of transpiration -
| Wind speed
Increasing wind speed increases the transpiration rate as water evaporates quickly.
85
Factors of transpiration -
| Light
Increasing light increases the rate of transpiration as the stomata opens.
86
Cell adaptation for movement within plants -
| Root hair cell
Extension gives a large surface area to absorb water and minerals.
87
Cells adaptation for movement within plants -
| Xylem
Vessels are strengthened by lignin to withstand pressure. Cell walls are waterproof.
88
Cell adaptation for movement within plants -
| Phloem
End of cells contain pores to allow dissolved sugars to move between cells.
89
Cell adaptation for movement within plants -
| Guard cells & Stomata guard cells
Can open the stomata to allow gas exchange or close to prevent water loss.
90
Leaf structure and plant tissues -
| Epidermis
Covers the surfaces of the leaf; lets light penetrate.
91
Leaf structure and plant tissues -
| Xylem
Carries water and minerals from the roots around the plant.
92
Leaf structure and plant tissues -
| Phloem
Carries dissolved sugars made through photosynthesis around the plant.
93
Leaf structure and plant tissues -
| Palisade mesophyll
Where most photosynthesis takes place. Cells contain many chloroplasts. Absorbs light.
94
Leaf structure and plant tissues -
| Spongy mesophyll
Some photosynthesis. Has air spaces for diffusion of carbon dioxide and oxygen.
95
Leaf structure and plant tissues -
| Guard cells
Cells that open and close stomata.
96
Leaf structure and plant tissues -
| Stoma
Opening that allows carbon dioxide and oxygen to diffuse in and out of the leaf.
97
Pathogens and disease -
| Measles
Pathogen - virus
Spread - droplets from sneezes and coughs
Effect - can be fatal
Prevention - vaccination of children
98
Pathogens and disease -
| HIV
Pathogen - virus
Spread - sexual contact, needle exchange
Effect - damages some white blood cells
Prevention - antiretroviral drugs when infected
99
Pathogens and disease -
| Tobacco mosaic virus
Pathogen - virus
Spread - direct contact
Effect - mottling leaves, reduces photosynthesis
100
Pathogens and disease -
| Salmonella
Pathogen - bacteria
Spread - infected food
Effect - fever, abdominal cramps, diarrhoea, vomiting
Prevention - vaccinations of poultry (chickens)
101
Pathogens and disease -
| Gonorrhoea
Pathogen - bacteria
Spread - sexual contact
Effect - discharge from penis/vagina, pain when urinating
Prevention - controlled by anitbiotics, spread prevented by condoms
102
Pathogens and disease -
| Rose black sport
Pathogen - fungus
Spread - spores carried by water or wind
Effect - leaves turn yellow, fall early. Photosynthesis reduced
Prevention - treated by fungicides or destroying affected leaves
103
Pathogens and disease -
| Malaria
Pathogen - protist
Spread - by a vector - mosquito
Effect - fever, can be fatal
Prevention - preventing mosquito's from breeding, using mosquito nets
104
Non-specific defences -
| Tranchea and bronchi
Produces mucus to trap pathogens. Contains cilia to move mucus for swallowing.
105
Non-specific defences -
| Nose
Contains hairs and mucus to trap pathogens.
106
Non-specific defences -
| Stomach
Contains hrydrochloric acid to destroy pathogens.
107
Non-specific defences -
| Skin
Physical barrier to pathogens.
108
Key terms -
| Pathogen
A microorganism that causes disease.
109
Key terms -
| Bacteria
A type of pathogen that produces toxins that damage tissues.
110
Key terms -
| Viruses
A type of pathogen that lives and replicates with cells and causes cell damage. It is difficult to kill viruses without damaging cells.
111
Key terms -
| Antibodies
Some white blood cells produce antibodies. These bind to pathogens and destroy them or stick them together.
112
Key terms -
| Antitoxins
Some white blood cells produce antitoxins. Antitoxins neutralise toxins.
113
Key terms -
| Antibiotics
Antibiotics kill bacteria. Specific antibiotics should be used for specific bacteria. Some bacteria are resistant to antibiotics. Do not kill viruses.
114
Key terms -
| Painkillers
Painkillers relive symptoms but don't kill pathogens.
115
Key terms -
| Phagocytosis
Some white blood cells engulf pathogens.
116
Drugs -
| Aspirin
Originates from the willow tree.
117
Drugs -
| Digitalis
A heart drug. Originates from foxglove plants.
118
Drugs -
| Penicillin
Discovered by Alexander Fleming from the penicillium fungus.
119
Drugs -
| New drugs
Most new drugs are synthesised by chemists in the pharmaceutical industry. The starting point may be a chemical extracted from a plant.
120
Clinical trials -
| Preclinical - cells, animals
Tests for toxicity and efficacy before testing humans.
121
Clinical trials -
| Healthy volunteers
Very low doses to test for toxicity.
122
Clinical trials -
| Patients
Larger groups. Test for toxicity, efficacy and dose. Placebos may be used in double-blind trial.
123
Clinical trial key terms -
| Placebo
A drug with no active ingredients, designed to mimic a real drug. Used to test i the effects of a drug on a patient are just psychological.
124
Clinical trial key terms -
| Double-blind trial
The volunteers do not know which groups they are in, and neither do the researchers, until the end of the trial.
125
Clinical trial key terms -
| Toxicity
How harmful the drug is. May have dangerous side effects.
126
Clinical trial key terms -
| Efficacy
How effective the drug is.
127
Clinical trail key terms -
| Dose
The amount of the drug given to the patient.
128
Photosynthesis equation
Carbon dioxide + water = glucose + oxygen
129
Key terms -
| Chloroplast
The plant organelle where photosynthesis takes place.
130
Key terms -
| Chlorophyll
The green pigment that absorbs energy from light.
131
Key terms -
| Endothermic
Photosynthesis takes energy in (in the form of light). It is an endothermic reaction.
132
Key terms -
| Diffusion
The spreading out of particles by random motion from where they are in high concentration. Occurs is gasses and liquids.
133
Uses of glucose
- Used in respiration to provide energy
- Converted into starch for storage
- Converted into fats and oils for storage
- Produce cellulose to strengthen cell wall
- Produce amino acids to make proteins (also needs nitrate ions from the soil)
134
Limiting factor
The factor that stops the rate of photosynthesis from increasing; could be light intensity, carbon dioxide, temperature or amount of chlorophyll.
135
Respiration -
| Energy
Energy in organisms is needed for chemical reactions to build larger molecules, movement and keeping warm.
136
Respiration -
| Aerobic respiration
Aerobic respiration provides energy. It requires oxygen. It is an exothermic reaction (produces heat). In mitochondria.
137
Aerobic respiration word equation
glucose + oxygen = carbon dioxide + water
138
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Respiration -
Anaerobic respiration (muscles)
```
No oxygen needed. Provides less energy than aerobic respiration as glucose not fully oxidised. Occurs during intensive exercise. In cytoplasm.
139
Respiration -
| Lactic acid
Produced in anaerobic respiration in muscles. Build up of lactic acid causes fatigue. Lactic acid must be taken to the liver by the blood so that it can be oxidised back to glucose.
140
Respiration -
| Oxygen debt
The amount of extra oxygen the body needs after exercise to react with the lactic acid and remove it.
141
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Respiration -
Anaerobic respiration (plant & yeast cells)
```
No oxygen needed. In yeast cells it is called fermentation - economically important for manufacture of bread and alcoholic drinks. In cytoplasm.
142
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Respiration -
Anaerobic respiration (plant & yeast cells) word equation
```
glucose = ethanol + carbon dioxide
143
Response to exercise -
| Increase in breathing rate
Increases rate at which oxygen is taken in the lungs.
144
Response to exercise -
| Increase in heart rate
Oxygenated blood is pumped around the body at a faster rate. Carbon dioxide is removed at a faster rate.
145
Response to exercise -
| Increase in breath volume
A greater volume of oxygen is taken into each breath.
146
Metabolism
The sum of all the reactions in a cell or body. Some of these reactions require the energy released from respiration.
147
Metabolism reactions
- Conversion of glucose to starch, cellulose or glycogen
- Formation of lipids from glycerol and fatty acids
- Use of glucose and nitrates to make amino acids (plants only)
- Respiration
- Breakdown of proteins to urea
