All biology Flashcards
1
Q
Nucleus function
A
Controls cell activity
Makes proteins
Contains chromosomes- DNA which carries the genes
2
Q
Cell membrane function
A
Boundary between cytoplasm and surroundings
Controls what goes in and out the cell
Selectively permeable
3
Q
Cytoplasm function
A
Jelly-like liquid where chemical reactions occurr
4
Q
Mitochondria function
A
Aerobic respiration
Produces atp
5
Q
Ribosomes function
A
Make proteins from amino acids
6
Q
Chloroplasts
A
Absorb light energy use it to carry out photosynthesis and make biological molecules for plant cells
7
Q
Cell wall
A
Made of cellulose
Keeps plant in fixed shape
8
Q
Vacuole
A
Filled with sap
Stores dissolved sugars minerals ions and other substances
9
Q
Calculating magnification
A
Objective magnification = size of image / size of object
10
Q
three parts of the plant cell that would not be found in an animal cell
A
vacuole and chloroplasts and cell wall
11
Q
How is the plant cell different from the bacterial cell?
A
chloroplasts in a plant cell
12
Q
what are pathogens?
A
microorganisms that can cause disease
13
Q
What is nutrition?
A
Makes glucose, which can be used to make other biological molecules, by photosynthesis or eat and digest other organisms to absorb biological molecules
14
Q
What is Respiration?
A
Chemical reaction, transferring energy from glucose to form ATP
15
Q
What is growth?
A
Increase in size and mass due to increase in cell number
16
Q
What is reproduction?
A
Production of new organisms (offspring)
17
Q
What is homeostatis?
A
Control of internal conditions, such as water potential and temperature
18
Q
What is movement?
A
Change of position or shape of organs (e.g. leaf moving towards light) or organism
19
Q
What is excretion?
A
Removal of waste products from chemical reactions (e.g. carbon dioxide)
20
Q
What is sensitivity?
A
Detect and respond to changes in the organism’s surroundings
21
Q
ingestion process
A
food entering the mouth
22
Q
digestion process
A
break down large molecules to small molecules
23
Q
absorption process
A
Small food molecules move from the small intestine into the blood
24
Q
assimilation synthesis process
A
Small food molecules are used to build large molecules
25
egestion
removal of undigested food from the anus (faeces)
26
describe the process of digestion in the mouth
Mechanical digestion breaks down the food in the mouth into smaller pieces. Then amylase in your saliva breaks starch down into shorter chains of glucose molecules
27
In what way is the structure of the artery different from the vein
artery has no valves, narrower lumen, thicker wall, more muscle, more elastic
28
artery function
takes oxygenated blood from the heart to the body
29
vein function
takes deoxygenated blood from the body to the heart
30
Blood vessels in the Pulmonary circulation
pulmonary vein and artery
31
Blood vessels in the Systemic circulation
vena cava, hepatic portal vein, renal artery and vein, aorta, hepatic artery and vein-mesenteric artery
32
Why do larger organisms have to have a circulatory system?
To deliver food and oxygen to cells and remove carbon dioxide and waste, effective diffusion
33
Arteries three specialisations for their functions
1. Large in diameter, muscular with thick walls- important to contract and keep blood flowing at high pressure
2. elastic walls important because they stretch and recoil to keep blood moving under high pressure without bursting
3. Smooth lining (endothelium) important for stopping blood clots forming
34
Veins four specialisations for their functions
1. large in diameter, important for plenty of space for blood to move, reducing loss of pressure
2. Thin muscle layer in wall important to contract to maintain pressure and keep blood moving
3. Smooth lining (endothelium) important to stop blood clots
4. Pocket valves important to ensure blood only flows in one direction, can push blood up the body
35
Capillaries two specialisations for their functions
1. Narrow important to slow down blood flow, so that exchange of substances with cells can happen
2. wall is one cell thick important for fast diffusion distance
36
Describe the cardiac cycle (8 points)
1. Blood flows from veins into atria
2. Atria contract
3. Blood flows into ventricles
4. Ventricles contract
5. Tricuspid and bicuspid valves close
6. Blood flows into arteries & away from the heart
7. Ventricles relax
8. Semi-lunar valves close
37
Why is the left ventricle thicker than the right ventricle?
the left has higher pressure to withstand as it has to pump blood around the body
38
Plasma description and function
straw like liquid, mainly water- transports blood cells
39
Phagocytes description and function
a type of white blood cell that ingests and destroys pathogens such as bacteria
40
Lymphocytes description and function
cells with a very large nucleus that make antibodies
41
Platelets description and function
Platelets description and function
42
Red blood cells description and function
small red cells that transport oxygen
43
What proteins do red blood cells contain?
haemoglobin
44
How is oxygen carried by red blood cells?
oxyhaemoglobin
45
Red blood cells have no nucleus, but how does this help them?
More space for haemoglobin and oxygen to be transported
46
Red blood cells have a biconcave shape, how does this adaptation help them?
Faster rate of diffusion due to the surface area to volume ratio
47
Order the levels of organisation in organisms from largest to smallest
```
organ system- largest
organ
tissue
cell
organelle
```
48
What is diffusion?
The random movement of particles from an area of high concentration to low concentration
49
What is Osmosis?
The net diffusion of free water molecules from an area of high water concentration to an area of low concentration across a partially permeable membrane
50
What is active transport
The movement of molecules from an area of low concentration to an area of high concentration using ATP
51
What 4 main factors affect the rate of diffusion and osmosis?
1. TEMPERATURE- at higher temperatures molecules have more kinetic energy so they move faster and diffusion is faster
2. CONCENTRATION GRADIENT- if there is a large difference in concentration between areas, then diffusion is fast
3. DISTANCE- diffusion takes longer when the molecules have further to travel
4. SURFACE AREA TO VOLUME RATIO- a larger surface area speeds up diffusion as there are more opportunities for the molecules to move
52
What is a stimuli?
Change in the animal's surroundings (eg ball being thrown at you)
53
What is a receptor?
The organ which detects the change (eg your eye)
54
What is an effector in the example of a ball being thrown at you?
The muscles as they contract to catch the ball
55
What is the energy conversion of the eye as a receptor
Light --> electrical impulses
56
What is in the central nervous system?
Brain and spinal chords
57
What is in the peripheral nervous system?
Cranial nerves and spinal nerves
58
2 advantages of reflex actions
1. The behaviour does not need to be learned so the damage can be avoided at an early age
2. The response is fast and automatic meaning the damage done is reduced
59
What is the function of rods?
Sensitive to low light, detects shades of grey
Provides us with night vision when you can see shapes not colours
Found in the retina but not in the centre of the fovea or blind spot
60
What is the function of cones?
Sensitive only to high light intensity (doesn't operate in poor light)
Detects colour
There are three types, sensitive to red, green and blue light
Concentrated in the fovea
61
What is the cornea?
A curved transparent disc at the front of the eye. Does most of the focussing.
62
What is the pupil?
A circular opening whose size is controlled by the Iris.
63
What is the lens?
It is soft, flexible and transparent. Its shape can be changed to fine tune the focussing of light onto the retina
64
What are the ciliary muscles?
A ring of muscle at the edge of the eye which circles the lens. When it relaxes, the lens gets thinner. When it contracts, the lens gets fatter.
65
What is the suspensory ligament
Strong fibres which attach the lens to the ciliary muscle
66
What is the retina?
Contains light sensitive cells called rods and cones
67
What is the optic nerve?
Consists of many neurones which carry impulses from the retina to the brain
68
What is the fovea?
The region of the retina with the greatest number of cones
69
What is the conjunctiva?
A mucous membrane that covers the eye to prevent infection
70
Photosynthesis word and symbol equation
Carbon dioxide + water --> oxygen + glucose
| 6CO2 + 6H2O --> 6O2 + C6H12O6
71
Describe the test for reducing sugars (glucose)
1. Add benedict's solution to a sample of food (in solution)
2. Place in a water bath at 80'C for 5 minutes
3. If glucose is present, the colour will change from blue to brick red. (If it turns green, yellow or or orange it is still a positive result but has a lower concentration of the sugar)
72
Describe the test for starch
1. Add a few drops of orange iodine solution to the sample on a spotting tile
2. A blue-black colour indicates the presence of starch
73
Describe the test for protein
(Biuret)
1. Add 2cm cubed water to a food sample and shake (if not already liquid)
2. Add an equal volume of dilute potassium hydroxide and shake
3. Add two drops of 1% copper sulfate solution
4. If protein is present then a pale purple will develop
74
Describe the test for lipids
(Emulsion)
1. The food sample is placed in a test tube
2. Add a small volume of absolute ethanol and shake to dissolve any lipid in the alcohol
3. Add an equal volume of water
4. A cloudy white colour (caused by an emulsion forming) indicates the presence of lipids
75
How does gas exchange occur in the alveoli?
Oxygen diffuses from the air into the red blood cells, where it binds with the haemoglobin for transport. Carbon dioxide, dissolved in the plasma diffuses into the blood into the alveolus
76
How are the alveoli adapted for efficient gas exchange?
Large surface area, high concentration gradient and short diffusion distance speed up diffusion
77
Describe the effect of exercise on heart rate
When we exercise, our body needs more glucose and oxygen for aerobic respiration so the heart rate increases so that more blood can travel to the muscles
Changes in heart rate are controlled by nerve impulses from a part of the brain called the medulla
- When exercise starts, the muscles produce more carbon dioxide in aerobic respiration
- Sensors in the aorta and carotid artery detect this increase
- They send nerve impulses to the medulla
- The medulla responds by sending nerve impulses along the accelerator nerve
- The accelerator nerve increases the heart rate
- More blood is supplied to the muscles to meet the demands of increased aerobic respiration
78
Insulin gland and function
Pancreas
| Causes liver and muscles to take up glucose and convert it to glycogen for storage
79
ADH gland and function
Pituitary gland
| Reduces the amount of water loss in urine
80
Oestrogen gland and function
Ovaries
| Stimulates uterus lining to develop and the development of secondary female characteristics
81
Progesterone gland and function
Ovaries
| Maintains uterus lining and controls the development of secondary female characteristics
82
Testosterone gland and function
Testes
| Stimulates development of male secondary sexual characteristics
83
Adrenaline gland and function
Adrenal gland
| Increases heart and breathing rate for fight, fright or flight
84
FSH gland and function
Pituitary gland
| Stimulates the egg to mature in the ovary
85
LH gland and function
Stimulates the release of an egg from the ovary (ovulation)
86
5 points about the phloem
1. Consists of living cells
2. Tubes are formed by cells arranged end to end but have cell walls made up of cellulose
3. The sugar made in photosynthesis is converted to sucrose
4. Phloem transports sucrose and amino acids from the leaves where they are made to the growing points
5. Moving sucrose and amino acids around the plant require energy. This is called translocation
87
6 points about the xylem
- Made up of thick walled dead cells which contain no cytoplasm, they are completely hollow and arranged end to end
- The cell wall contains waterproof lignin
- The end walls have broken down so they form a continuous transport system through the plant
- transports water and mineral ions from the roots to the leaves
- Nitrate ions are needed to make amino acids and proteins
- Magnesium ions are needed to make chlorophyll
88
5 substances dissolved into the plasma
```
Digested food
Carbon dioxide
Hormones
Antibodies
Amino acids
```
89
What are the 4 components of blood
Red blood cells
White blood cells
Platelets
Plasma
90
What happens to your eyes in dim light
Radial muscles contract
Circular muscles relax
Iris is narrower and pupil dilates
91
What happens to your eyes in bright light
Radial muscles relax
Circular muscles contract
Iris is wider and pupil constricts
92
Describe the accommodation of your eye to focus on an object far away
Light rays entering the eye are almost parallel when they reach the cornea, so the lens does not need to refract them much to focus light onto the retina, the eye does this by:
- Relaxing ciliary muscles
- Meaning suspension ligaments are therefore pulled tight
- Lens is pulled thin and has a less convex shape
- Therefore there is less refraction of light
93
Describe the accommodation of your eye to focus on an object close up
Light rays entering eye are spreading out (diverging) so the lens needs to refract the light to ensure that it focusses on the retina. The light does this by:
- contracting the ciliary muscles
- Meaning suspensory ligaments are therefore slack
- Lens is not stretched out so becomes thicker with a more convex shape
- Therefore there is more refraction of light
94
Function of the head of the sperm cell
gain entry, break through egg membrane, chromosomes, DNA
95
Function of the middle part of the sperm cell
respiration for ATP and energy
96
Function of the tail of the sperm cell
swim and move around
97
How is the structure of the motor neurone cell adapted for its function
dendrites connect with other neurones, myeline sheet for insulation/ protection, connected to muscle fibres which allow muscle fibres to contract
98
Number of mitosis cells before cell division
23 pairs so 46 chromosomes
99
Number of meiosis chromosomes before cell division
23 pairs so 46 chromosomes
100
Number of mitosis chromosomes after cell division
23 pairs so 46 chromosomes
101
Number of Meiosis chromosomes after cell division
23 single chromosones
102
Number of cell divisions in Mitosis
1
103
Number of cell divisions in Meiosis
2
104
Number of daughter cells produced in Mitosis
2
105
Number of daughter cells produced in meiosis
4
106
Is a genetic variation produced in Mitosis?
no
107
Is genetic variation produced in Meiosis?
yes
108
How is Mitosis used?
To heal, grow, and reproduce (asexually)
109
How is Meiosis used?
To make gametes, sperm and egg cells, pollen, and ova
110
Testes function
Organ which makes sperm cells.
| Made up of many coiled tubules.
111
What does Mitosis do?
Creates genetically identical copies of your cells
| Allows you to grow and also replace damaged cells
112
What does meiosis do?
Makes genetically varied cells, which halve the number of chromosomes
It is important when making sex cells (gametes)
113
What is asexual reproduction?
Making identical copies of cells- mitosis
114
What is sexual reproduction in a human?
when a sperm and an egg cell fuse to reproduce
115
What is sexual reproduction in plants?
When an ova and pollen fuse together to reproduce
116
What is a haploid cell?
A cell that contains single chromosomes
117
What is a diploid cell?
A cell that contains pairs of chromosomes
118
3 facts about amniotic fluid
1. Stops foetal tissue from dying out
2. Reduction of mechanical shock
3. Water has a high SHC, thus it takes a lot of energy to change its temperature, which means the fluid is temperature regulated.
119
5 steps of mitosis
1. parent cell that wants to make copies of the cell. There are 23 pairs of chromosomes so it is a diploid
2. Need chromosomes to be copied. This process is called DNA replication
3. The pairs of chromosomes now line up and down the middle of the cell. Small fibres from opposite polls pull chromosomes apart, towards opposite ends.
4. Cell splits in half
5. Forms two genetically identical cells. Due to having 23 pairs of chromosomes, they are diploid.
120
Hormone that changes female body at puberty
oestrogen
121
Four changes to a girl at puberty
1. Breasts grow
2. Period starts
3. Hips widen
4. Become more attracted to boys
122
Role of the placenta in development of the embryo
1. Prevents mother’s blood from interacting with the embryo’s blood
2. Separates mother and baby so the mother’s white blood cells to not attack the embryo as they see it as a foreign body
3. Removes the embryo’s Co2 and Urea
4. Supplying the embryo with nutrients eg glucose and Co2 that the embryo needs to grow and develop fully
123
How do you know that a flower is insect pollinated?
1. Large petals
2. Stamens and anther enclosed
3. Stigma closed
4. Style shorter
5. Not feathery stigma
6. Reflect ultraviolet light to guide the insect
124
How do you know that a flower is wind pollinated?
1. Stamens and stigma are exposed outside of petals
2. The petals are small and usually green
3. There are no nectaries
125
Describe the 8 steps from the growth of the pollen tube to fruit formation
1. In plants pollen grains are deposited onto the stigma
2. The pollen grain normally grows a pollen tube which grows down through the style
3. Enzymes are secreted at the tip of the tube which digest the tissues of the style
4. When the tube reaches an ovule, the male gamete travels through the tube, entering the ovule through a small hole called the micropyle
5. It then fuses with the female gamete (ovum) in the process of fertilisation
6. The fertilised ovum divides by mitosis to form the embryo
7. The ovule develops into the seed
8. The ovary develops into the fruit
126
3 Conditions needed for germination
1. Oxygen to aerobically respire
2. Warmth- optimum temperature for enzymes
3. Water to activate the enzymes
127
Describe the test for germination
Cress seeds are added to cotton wool in test tubes
- Tube A is put in a fridge (no warmth) and the rest are kept on a windowsill
- In tube C, the cotton wool is moistened with boiled water and an oxygen absorber such as sodium pyrogallol is added (no oxygen)
- Tube E is wrapped in foil (no light)
- The cotton wool in tube B is kept dry (no water)
- Tube D has all the conditions present
Check for germination after 2-3 days- you could combine class results and calculate a % or mean length of each seed condition
128
What is Germination?
Germination is a process, controlled by enzymes , in which the seed begins to develop into a new young plant.
129
Human impact of CO2
Burning fossil fuels
| Slash and burn forest clearance
130
What is the independent variable?
What you are deliberately changing (named in question)
131
What is the dependent variable?
What you are measuring (named in question)
132
What is the control variable?
The factors which may affect the dependent variable (you keep the same)
133
Calculating magnification equation
objective magnification = size of image / size of object
134
Cell definition
Smallest function of human life and they contain a number of organelles (structures that carry out a specific process that the cells need to survive)
The cells in an organism are not all the same - there are many different type, each of which has a specific job. We describe these different types of cells as specialised cells
135
Tissues definition
A group of similar cells which work together to carry out the same function. eg muscle tissue in humans
136
Organs definition
Made up of several types of tissues working together to carry out a more complex function
137
Organ systems definition
Made up of several types of organs working together to carry out a complex function essential to life. eg circulating blood around the body
138
What is a stem cell?
A single cell that can replicate itself, or differentiate into many cell types
139
What is a specialised cell?
Stem cells differentiate (develop new features) to become specialised cells - ones that have the structures and proteins needed to carry out a specific job in the organism
140
Describe the function and features of the red blood cell
Function: to transport oxygen in the blood
Features:
- contains the protein haemoglobin, binds to and transports oxygen
- No nucleus, more space for haemoglobin
- Biconcave shape, larger surface area, so oxygen can enter and leave the cell more rapidly
141
Describe the function and features of the sperm cell
Function: to transport male genetic material to the egg cell
Features:
- Flagellum (tail), to allow the sperm cell to swim
- Many mitochondria, to provide the energy needed for swimming
- Acrosome, package of enzymes, to digest the jelly layer surrounding the egg cell
142
Describe the function and features of the Palisade (leaf) cell
Function: to carry out photosynthesis
Features:
- Many chloroplasts, trap light energy for photosynthesis
- Tall and thin, cells can pack tightly so more of the light reaching the leaf is absorbed
143
What are carbohydrates and what are they made of?
- made of carbon hydrogen and oxygen
- carbohydrates are broken down in a chemical reaction, respiration, to release energy in the form of ATP.
- Simple sugars (eg glucose and fructose) are the smallest units of carbohydrates
- Two sugar molecules can be joined together, eg glucose and fructose make sucrose.
144
Benefits of fertilisers
Provide elements needed by plants to grow well
Eg nitrogen, phosphorus, potassium
Make crops grow faster and bigger so that yields are increased
145
Downside to fertilisers
Can pollute water supplies causing eutrophication
Extra mineral ions cause algae to overgrow in water supplies, blocking sunlight and killing aquatic plants. As a result there is not enough oxygen dissolved in the water for aquatic organisms too survive
146
Name 3 chemical pesticides
Fungicides (kill fungi)
Herbicides (kill weeds)
Insecticides (kill insects)
147
Organ supplied with blood from hepatic portal vein and hepatic artery
Liver
148
Organ supplied blood by pulmonary artery
Lungs
149
Organ supplied with blood from renal artery
Kidney
150
What happens to fish protein in the atomach
The fish once at the stomach will start chemical digestion. Protease will then break down the proteins in to amino acids. The stomach produces hydrochrolic acid which helps to digest and kills any harmful microorganisms.
