B3 - Living and Growing Flashcards
(248 cards)
1
Q
B3 - Living and Growing
What do chemical reaction usually involve?
A
Being split apart or joined together.
2
Q
B3 - Living and Growing
How has genetic engineering helped plants with resistance?
A
Gene that causes resistance to frost damage, herbicides and disease can be cut and placed in a useful plant.
3
Q
B3 - Living and Growing
Energy from respiration can’t be used directly so used to make ATP. ATP acts as energy source for many cell processes and transports energy to where it is needed in a cell.
A
What is ATP?
4
Q
B3 - Living and Growing
Organism has to be killed - ok for plants but not humans.
A
What is the disadvantage of measuring dry mass?
5
Q
B3 - Living and Growing
What specialised organ systems do multicellular organisms need?
A
- Communicate between different cells (nervous system). 2. Supply cells with nutrients (circulatory). 3. Controls exchange of substances in environment (respiratory).
6
Q
B3 - Living and Growing
Happens when plenty of oxygen is available. Most efficient.
A
What is aerobic respiration?
7
Q
B3 - Living and Growing
Enzyme breaks down proteins in stomach. Works best at pH 2 - well-suited to acidic conditions in stomach.
A
What is Pepsin?
8
Q
B3 - Living and Growing
Double helix unzips to form 2 single strands and new nucleotides floating in nucleus join to complementary bases. Makes an exact copy leaving 2 identical double-stranded molecules of DNA
A
How does DNA replicate itself?
9
Q
B3 - Living and Growing
To free up space for more haemoglobin so they can carry more oxygen.
A
Why don’t red blood cells have a nucleus?
10
Q
B3 - Living and Growing
What happens at the 2nd stage of mitosis?
A
DNA coils into double-armed chromosomes. Arms are exact copies of each other - contain exactly same DNA.
11
Q
B3 - Living and Growing
What happens in the left atrium?
A
Receives oxygenated blood from lungs via pulmonary vein
12
Q
B3 - Living and Growing
They have a high specificity for their substrate - has to fit in active site. If shape doesn’t match, reaction won’t be catalysed. Called ‘lock and key’ mechanism.
A
Why are enzymes ‘picky’?
13
Q
B3 - Living and Growing
Part of an enzyme where it joins on to its substrate to catalyse reaction.
A
What is the active site?
14
Q
B3 - Living and Growing
Production of protein gene normally codes for - or different protein produced instead.
A
What can a mutation stop?
15
Q
B3 - Living and Growing
What are they called if a chemical causes cancer?
A
Carcinogens e.g. cigarette smoke.
16
Q
B3 - Living and Growing
What is the 1st stage of meiosis?
A
DNA replicates and curls up to form double armed chromosomes.
17
Q
B3 - Living and Growing
What do capillaries have?
A
Permeable walls so substances can diffuse in and out. Walls usually only 1 cell thick - increases rate of diffusion because of shorter distance.
18
Q
B3 - Living and Growing
Weighing animal/plant.
A
What is involved in measuring wet mass?
19
Q
B3 - Living and Growing
Carcinogens e.g. cigarette smoke.
A
What are they called if a chemical causes cancer?
20
Q
B3 - Living and Growing
Period between infancy and puberty. Steady growth.
A
What is childhood?
21
Q
B3 - Living and Growing
What increases the chance of mutations?
A
Ionising radiation: including X-rays and UV light as well as radioactive substance. Greater dose, greater chance of mutation. Chemicals: called mutagens.
22
Q
B3 - Living and Growing
What are nucleotides?
A
Small groups which make up strands of DNA. Each nucleotide contains a small molecule called a base.
23
Q
B3 - Living and Growing
What are the benefits of cloning?
A
1) can mass produce animals with desirable characteristics. 2) human. Embryos could be produced by cloning adult body cells and embryos could supply stem cells which would reduce the risk of rejection
24
Q
B3 - Living and Growing
What are the 4 parts of a bacteria cell?
A
Cell membrane, cell wall, cytoplasm, single strand of DNA (not a nucleus)
25
# B3 - Living and Growing
Cell membrane, cell wall, cytoplasm, single strand of DNA (not a nucleus)
What are the 4 parts of a bacteria cell?
26
# B3 - Living and Growing
Why is cloning plants easier than animals?
Many plant cells keep ability to differentiate whereas animal cells lose that at an early age.
27
# B3 - Living and Growing
What is the 3rd stage of meiosis?
In 1st division, pairs split up - chromosomes in each pair move to opposite poles of cell. In each new cell there are no pairs - just one of each of the 23 types.
28
# B3 - Living and Growing
Nucleus, cell wall, cytoplasm, vacuole, chloroplasts, cell membrane.
What are the 6 parts of a plant cell?
29
# B3 - Living and Growing
Infancy, childhood, adolescence, maturity/adulthood, old age.
What are the five main stages of growth for humans?
30
# B3 - Living and Growing
What determines the function of a cell?
Genes that are 'switched on' e.g. in muscle, genes for muscle cell production are on, but genes for proteins specific to bone, nerve and skin cells switched off.
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# B3 - Living and Growing
You'll only get good plants so no time is wasted growing bad ones. Possible to mass produce plants that are hard to grow from seeds.
What are the positive of cloning plants?
32
# B3 - Living and Growing
How does DNA replicate itself?
Double helix unzips to form 2 single strands and new nucleotides floating in nucleus join to complementary bases. Makes an exact copy leaving 2 identical double-stranded molecules of DNA
33
# B3 - Living and Growing
Cells which need lots of energy such as liver cells and muscle cells.
Which cells have lots of mitochondria?
34
# B3 - Living and Growing
Nucleus of egg cell removed so it had no genetic info. Another nucleus was inserted with all genetic info. Cell given electric shocks to divide by mitosis and embryo was implanted into surrogate mother until it is born.
What does nuclear transfer involve?
35
# B3 - Living and Growing
1) involves changing body cells, particularly those cells most affected. Wouldn't affect gametes so offspring could still get it. 2) change cells in gametes so offspring won't be affected.
What are the two types of gene therapy?
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# B3 - Living and Growing
It doesn't tell you about change in width, diameter, number of branches etc.
What is the disadvantage of measuring length?
37
# B3 - Living and Growing
What is the disadvantage of measuring wet mass?
Very changeable e.g. a plant will be heavier if it’s just rained or animals will be heavier if they have a full bladder or have just eaten.
38
# B3 - Living and Growing
Haemolglobin which gives its colour - contains lot of iron.
What do red blood cells contain?
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# B3 - Living and Growing
glucose + oxygen → carbon dioxide + water (+energy)
What is the word equation for aerobic respiration?
40
# B3 - Living and Growing
Where are proteins made?
In cytoplasm by ribosomes.
41
# B3 - Living and Growing
Pale yellow liquid carrying everything that needs transporting around body.
What is plasma?
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# B3 - Living and Growing
What do veins have?
Walls aren’t as thick - lower pressure. Bigger lumen helps blood flow. Valves keep blood flowing in right direction.
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# B3 - Living and Growing
Small with long tails to swim. Lots of mitochondria to provide energy for swimming. Acrosome at front can release enzymes to digest through membrane of egg cell.
How are male gametes adapted for their function?
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# B3 - Living and Growing
What happens in the mitochondria?
Reactions involved in respiration.
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# B3 - Living and Growing
So they can fit through capillaries easily.
Why are red blood cells flexible?
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# B3 - Living and Growing
What does mRNA do?
Carry code between DNA and ribosome.
47
# B3 - Living and Growing
Gene has been put into bacteria and are cultured in a ferment. Human insulin is then extracted as it is produced.
What has genetic engineering done for insulin production?
48
# B3 - Living and Growing
Cytoplasm divides and you get 2 new cells containing exact same genetic material.
What happens at the 4th stage of mitosis?
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# B3 - Living and Growing
What is stem celll therapy?
Early human embryos contain lots of stem cells and these can be extracted and grown. Eventually may be used to grow tissue to treat medical conditions like nerve damage, spinal injuries, skin cells, skin grafts.
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# B3 - Living and Growing
What are the stages of genetic engineering?
1) gene that produces desirable characteristic is selected 2) this is cut from DNA using enzymes and isolated 3) useful gene inserted into DNA of another organism 4) organisms then replicate and then there are loads of organisms producing same thing.
51
# B3 - Living and Growing
What are the advantages of genetic engineering?
Can produce organisms with new and useful features very quickly
52
# B3 - Living and Growing
Biological catalysts which speed up reaction without being changed or used up in reaction.
What are enzymes and what do they do?
53
# B3 - Living and Growing
In 1st division, pairs split up - chromosomes in each pair move to opposite poles of cell. In each new cell there are no pairs - just one of each of the 23 types.
What is the 3rd stage of meiosis?
54
# B3 - Living and Growing
When you want identical cells e.g. grow or when you need to replace worn out cells and repair tissue.
When does mitosis happen?
55
# B3 - Living and Growing
Carry blood to heart.
What do veins do?
56
# B3 - Living and Growing
Allows oxygenated blood to move through right ventricle and get pumped around rest of the body.
What does the aorta do?
57
# B3 - Living and Growing
Strong, thick and elastic walls to cope with pressure.
What do arteries have?
58
# B3 - Living and Growing
Bigger, can travel further, get nutrients in different ways, fewer things squash you. Allows for cell differentiation - different cells do different things. More complex - specialised organs, different shapes and behaviour/specifically adapted.
What are the advantages of being multicellular?
59
# B3 - Living and Growing
Can produce organisms with new and useful features very quickly
What are the advantages of genetic engineering?
60
# B3 - Living and Growing
What happens at the 1st stage of mitosis?
DNA in cell is replicated.
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# B3 - Living and Growing
Reduces gene pool and inbreeding can cause health problems because increased risk of genetic disorders. A disease may also wipe them out because there is less variation and they are closely related.
What are the disadvantages of selective breeding?
62
# B3 - Living and Growing
Nucleus, cell membrane, ribosome, cytoplasm, mitochondria
What are the 5 parts of an animal cell?
63
# B3 - Living and Growing
Why don’t red blood cells have a nucleus?
To free up space for more haemoglobin so they can carry more oxygen.
64
# B3 - Living and Growing
Carry code between DNA and ribosome.
What does mRNA do?
65
# B3 - Living and Growing
Receives oxygenated blood from lungs via pulmonary vein
What happens in the left atrium?
66
# B3 - Living and Growing
1) gene that produces desirable characteristic is selected 2) this is cut from DNA using enzymes and isolated 3) useful gene inserted into DNA of another organism 4) organisms then replicate and then there are loads of organisms producing same thing.
What are the stages of genetic engineering?
67
# B3 - Living and Growing
Process by which a cell changes to become specialised for its job
What is differentiation?
68
# B3 - Living and Growing
What is the symbol equation for aerobic respiration?
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O
69
# B3 - Living and Growing
What do arteries have?
Strong, thick and elastic walls to cope with pressure.
70
# B3 - Living and Growing
What does the right atrium receive?
Receives deoxygenated blood from body via vena cava
71
# B3 - Living and Growing
Ionising radiation: including X-rays and UV light as well as radioactive substance. Greater dose, greater chance of mutation. Chemicals: called mutagens.
What increases the chance of mutations?
72
# B3 - Living and Growing
What is the disadvantage of measuring dry mass?
Organism has to be killed - ok for plants but not humans.
73
# B3 - Living and Growing
Exchange materials at tissues. Supply food and oxygen. Remove carbon dioxide.
What do capillaries do?
74
# B3 - Living and Growing
glucose → lactic acid (+energy)
What is the word equation for anaerobic respiration?
75
# B3 - Living and Growing
How is blood pumped to the lungs?
Deoxygenated blood moves to right ventricle which pumps it to lungs via pulmonary artery
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# B3 - Living and Growing
In lungs it combines with oxygen to become oxyhaemoglobin and in body tissue it releases oxygen to cells.
What does haemoglobin do?
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# B3 - Living and Growing
What is adulthood/maturity?
Period between adolescence and old age. Growth stops.
78
# B3 - Living and Growing
What is the equation for Respiratory Quotient (RQ)?
Amount of CO₂ produced ÷ amount of O₂ used
79
# B3 - Living and Growing
Undifferentiated cells which can develop into different types of cells, tissues and organs depending on instructions given.
What are stem cells?
80
# B3 - Living and Growing
To develop best features. Includes: maximum yield of meat, grain, milk etc, good health and disease resistance, and other qualities like temperament, speed and attractiveness.
Why are organisms selectively bred?
81
# B3 - Living and Growing
What is the word equation for anaerobic respiration?
glucose → lactic acid (+energy)
82
# B3 - Living and Growing
Very changeable e.g. a plant will be heavier if it’s just rained or animals will be heavier if they have a full bladder or have just eaten.
What is the disadvantage of measuring wet mass?
83
# B3 - Living and Growing
What is ATP?
Energy from respiration can’t be used directly so used to make ATP. ATP acts as energy source for many cell processes and transports energy to where it is needed in a cell.
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# B3 - Living and Growing
Used in clotting blood.
What are platelets?
85
# B3 - Living and Growing
Genetically identical organisms
What are clones?
86
# B3 - Living and Growing
Walls aren’t as thick - lower pressure. Bigger lumen helps blood flow. Valves keep blood flowing in right direction.
What do veins have?
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# B3 - Living and Growing
What shape are red blood cells?
Biconcave disc/shape.
88
# B3 - Living and Growing
What has genetic engineering done for insulin production?
Gene has been put into bacteria and are cultured in a ferment. Human insulin is then extracted as it is produced.
89
# B3 - Living and Growing
What does the RQ tell you?
A value between 0.7 and 1 shows aerobic respiration. Above 1 shows anaerobic respiration - short of oxygen.
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# B3 - Living and Growing
Why does the left ventricle have a thicker wall?
More muscle because it has to pump blood around whole body whereas right ventricle only has to pump to lungs
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# B3 - Living and Growing
How are proteins made?
DNA controls this. Protein synthesis. Section of DNA codes a particular protein (gene). Proteins are made up of chains of molecules (amino acids). Order of bases determines amino acid. 3 bases makes 1 amino acid - joined together to make protein.
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# B3 - Living and Growing
How does the pH affect enzymes?
If too high/low, interferes with bonds holding enzyme together. Changes shape of active site and denatures enzyme. Optimum normally neutral pH7 but some exceptions.
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# B3 - Living and Growing
Where is deoxygenated blood pumped to?
Lungs
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# B3 - Living and Growing
What controls the characteristics of the zygote?
Controlled by combination of genes on its chromosomes.
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# B3 - Living and Growing
What do veins do?
Carry blood to heart.
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# B3 - Living and Growing
What is the basic process of selective breeding?
1) select best characteristic from existing stock 2) breed with each other 3) select best of offspring - breed together 4) continue process over several generations - desirable trait gets stronger and stronger.
97
# B3 - Living and Growing
Respiration without oxygen - after vigorous exercise and supply of oxygen to muscles is very low.
What is anaerobic respiration?
98
# B3 - Living and Growing
What are the advantages of being multicellular?
Bigger, can travel further, get nutrients in different ways, fewer things squash you. Allows for cell differentiation - different cells do different things. More complex - specialised organs, different shapes and behaviour/specifically adapted.
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# B3 - Living and Growing
Semilunar, tricuspid and bicuspid valves
What prevents back flow in the heart?
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# B3 - Living and Growing
What happens at the 3rd stage of mitosis?
Chromosomes line up at centre of cell and divide as cell fibres pull them apart. 2 arms or each chromosome go to opposite poles of 1 cell. Membranes form around 2 sets of chromosomes.
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# B3 - Living and Growing
1. Communicate between different cells (nervous system). 2. Supply cells with nutrients (circulatory). 3. Controls exchange of substances in environment (respiratory).
What specialised organ systems do multicellular organisms need?
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# B3 - Living and Growing
What does gene therapy involve?
Altering a persons genes in an attempt to cure a genetic disorder.
103
# B3 - Living and Growing
What things don't bacteria cells have?
Chloroplasts or mitochondria. Also don’t have a true nucleus but a single strand of DNA instead which floats freely in cytoplasm.
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# B3 - Living and Growing
Period between adolescence and old age. Growth stops.
What is adulthood/maturity?
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# B3 - Living and Growing
Easy to measure.
What is the advantage of measuring wet mass?
106
# B3 - Living and Growing
Pumped at higher pressure and increases rate of blood flow so more oxygen delivered to cells. Mammals need lots of oxygen to maintain steady body temperature.
What are the advantages of a double circulatory system?
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# B3 - Living and Growing
At fertilisation male and female gametes combine to form a diploid cell.
What is a zygote?
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# B3 - Living and Growing
Easy to measure.
What is the advantage of measuring length?
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# B3 - Living and Growing
What are the positive of cloning plants?
You'll only get good plants so no time is wasted growing bad ones. Possible to mass produce plants that are hard to grow from seeds.
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# B3 - Living and Growing
What is the 2nd stage of meiosis?
Chromosomes arrange themselves into pairs. Both chromosomes contain information about same feature.
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# B3 - Living and Growing
What are the 5 parts of an animal cell?
Nucleus, cell membrane, ribosome, cytoplasm, mitochondria
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# B3 - Living and Growing
What is differentiation?
Process by which a cell changes to become specialised for its job
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# B3 - Living and Growing
What is mitosis?
When a cell reproduces itself by splitting to form 2 identical offspring.
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# B3 - Living and Growing
What are the complementary pairs of bases in DNA?
Adenine and Thymine (A and T), Guanine and Cytosine (G and C)
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# B3 - Living and Growing
Amount of CO₂ produced ÷ amount of O₂ used
What is the equation for Respiratory Quotient (RQ)?
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# B3 - Living and Growing
When it gets too hot, some bonds holding enzyme together break. Enzyme loses its shape, active site doesn't fit substrate - can't catalyse reaction and reaction stops. Enzyme can't function. Change in shape is irreversible.
What is denaturing?
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# B3 - Living and Growing
What is a zygote?
At fertilisation male and female gametes combine to form a diploid cell.
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# B3 - Living and Growing
Roughly first two years of life - rapid growth.
What is infancy?
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# B3 - Living and Growing
Biconcave disc/shape.
What shape are red blood cells?
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# B3 - Living and Growing
What is aerobic respiration?
Happens when plenty of oxygen is available. Most efficient.
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Enzymes - biological catalysts Carrier molecules - to transport smaller molecules Hormones - e.g. Insulin Structural proteins - physically strong e.g. Collagen
What are the 4 functions of proteins?
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# B3 - Living and Growing
How can Q₁₀ be calculated?
Rate at higher temperature ÷ rate at lower temperature
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In cytoplasm by ribosomes.
Where are proteins made?
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# B3 - Living and Growing
In early human embryos and in adults - but only in certain places, like bone marrow (aren’t as versatile as embryonic stem cells).
Where are stem cells found?
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If plants suffer from a disease or doing badly because of environmental changes they all have same problem because of same genes and lack of genetic variation.
What are the negatives of cloning plants?
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# B3 - Living and Growing
What is involved in measuring dry mass?
Drying out organism before weighing it.
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# B3 - Living and Growing
What is the 4th stage of meiosis?
Each chromosome splits in half an 1 arm ends up in each new cell. 4 new cells (daughter cells) are made.
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# B3 - Living and Growing
Why are enzymes 'picky'?
They have a high specificity for their substrate - has to fit in active site. If shape doesn't match, reaction won't be catalysed. Called 'lock and key' mechanism.
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# B3 - Living and Growing
What is anaerobic respiration?
Respiration without oxygen - after vigorous exercise and supply of oxygen to muscles is very low.
130
# B3 - Living and Growing
What is the substrate?
Molecule which is changed in reaction.
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# B3 - Living and Growing
Being split apart or joined together.
What do chemical reaction usually involve?
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# B3 - Living and Growing
Altering a persons genes in an attempt to cure a genetic disorder.
What does gene therapy involve?
133
# B3 - Living and Growing
What are the risks with cloning?
Some evidence cloned animals may not be as healthy as normal ones and as it is new there are consequences we are not yet aware of.
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# B3 - Living and Growing
Some evidence cloned animals may not be as healthy as normal ones and as it is new there are consequences we are not yet aware of.
What are the risks with cloning?
135
# B3 - Living and Growing
Deoxygenated blood moves to right ventricle which pumps it to lungs via pulmonary artery
How is blood pumped to the lungs?
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# B3 - Living and Growing
Chromosomes arrange themselves into pairs. Both chromosomes contain information about same feature.
What is the 2nd stage of meiosis?
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Francis Crick and James Watson
Who were the first to build a model of DNA?
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Chloroplasts or mitochondria. Also don’t have a true nucleus but a single strand of DNA instead which floats freely in cytoplasm.
What things don't bacteria cells have?
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# B3 - Living and Growing
What is the advantage of measuring dry mass?
Not affected by water in plant or by how much it's eaten.
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# B3 - Living and Growing
May benefit organism. Gives a survival advantage and passed on to offspring - natural selection and evolution. Some mutations aren't harmful or helpful.
How are some mutations helpful?
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# B3 - Living and Growing
Why is gene therapy on gametes controversial?
Unexpected consequences and problems may be inherited by offspring. Concerns it may lead to designer babies where parents choose what genes their child has.
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What does a Q₁₀ value of 2 mean?
Rate doubles when temperature is rasied by 10°C
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Begins with puberty and continues until body development and growth are complete. Rapid growth.
What is adolescence?
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# B3 - Living and Growing
What is the active site?
Part of an enzyme where it joins on to its substrate to catalyse reaction.
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What is the main risk with genetic engineering?
May be unexpected harmful effects like bacteria mutating and becoming pathogenic. May become more harmful and unpredictable.
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What do red blood cells contain?
Haemolglobin which gives its colour - contains lot of iron.
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What does haemoglobin do?
In lungs it combines with oxygen to become oxyhaemoglobin and in body tissue it releases oxygen to cells.
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May be unexpected harmful effects like bacteria mutating and becoming pathogenic. May become more harmful and unpredictable.
What is the main risk with genetic engineering?
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What is involved in measuring wet mass?
Weighing animal/plant.
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How are some mutations helpful?
May benefit organism. Gives a survival advantage and passed on to offspring - natural selection and evolution. Some mutations aren't harmful or helpful.
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Some think is it wrong as it's for human benefit - animals suffer. People worry it won't stop, people will decide characteristics of their children. Evolutionary consequences not known so people think it is irresponsible because of impact on future generations.
What are the moral and ethical issues on genetic engineering?
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Hole down middle of an artery, capillary or vein.
What is the lumen?
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# B3 - Living and Growing
Which cells have lots of mitochondria?
Cells which need lots of energy such as liver cells and muscle cells.
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Receives deoxygenated blood from body via vena cava
What does the right atrium receive?
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# B3 - Living and Growing
What is the lumen?
Hole down middle of an artery, capillary or vein.
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# B3 - Living and Growing
Carry blood away from heart.
What do arteries do?
157
# B3 - Living and Growing
What is Pepsin?
Enzyme breaks down proteins in stomach. Works best at pH 2 - well-suited to acidic conditions in stomach.
158
# B3 - Living and Growing
What is plasma?
Pale yellow liquid carrying everything that needs transporting around body.
159
# B3 - Living and Growing
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O
What is the symbol equation for aerobic respiration?
160
# B3 - Living and Growing
A change in DNA base sequence. Occurs within a gene.
What is a mutation?
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What does the aorta do?
Allows oxygenated blood to move through right ventricle and get pumped around rest of the body.
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# B3 - Living and Growing
Would have to be lots of surrogate pregnancies with high rate of miscarriage and stillbirths. Clones have often been unhealthy and died prematurely. It might be psychologically damaged by the knowledge it is a clone.
What are the ethical issues with cloning?
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# B3 - Living and Growing
What are enzymes and what do they do?
Biological catalysts which speed up reaction without being changed or used up in reaction.
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A value between 0.7 and 1 shows aerobic respiration. Above 1 shows anaerobic respiration - short of oxygen.
What does the RQ tell you?
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How has genetic engineering helped in countries which depend on rice?
Vitamin A can be a problem in these areas so scientists have taken a gene from beta-carotene production from carrots and put it into rice.
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What are the advantages of a double circulatory system?
Pumped at higher pressure and increases rate of blood flow so more oxygen delivered to cells. Mammals need lots of oxygen to maintain steady body temperature.
167
# B3 - Living and Growing
DNA replicates and curls up to form double armed chromosomes.
What is the 1st stage of meiosis?
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# B3 - Living and Growing
Animals grow until a finite size (full growth) whereas plans grow continuously.
How do plants cells grow differently to animal cells?
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Nuclear transfer
What process created dolly the sheep?
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Unexpected consequences and problems may be inherited by offspring. Concerns it may lead to designer babies where parents choose what genes their child has.
Why is gene therapy on gametes controversial?
171
# B3 - Living and Growing
What are the five main stages of growth for humans?
Infancy, childhood, adolescence, maturity/adulthood, old age.
172
# B3 - Living and Growing
What is the advantage of measuring wet mass?
Easy to measure.
173
# B3 - Living and Growing
Genes that are 'switched on' e.g. in muscle, genes for muscle cell production are on, but genes for proteins specific to bone, nerve and skin cells switched off.
What determines the function of a cell?
174
# B3 - Living and Growing
Controlled by combination of genes on its chromosomes.
What controls the characteristics of the zygote?
175
# B3 - Living and Growing
What is selective breeding?
When humans artificially select plants or animals they are going to breed and have their genes remain in population, according to what we want from them.
176
# B3 - Living and Growing
What do arteries do?
Carry blood away from heart.
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DNA in cell is replicated.
What happens at the 1st stage of mitosis?
178
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How much rate changes when temperature is raised by 10°C
What does the Q₁₀ value show?
179
# B3 - Living and Growing
What are the negatives of cloning plants?
If plants suffer from a disease or doing badly because of environmental changes they all have same problem because of same genes and lack of genetic variation.
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# B3 - Living and Growing
What is involved in measuring length?
Measuring length or height of a plant/animal.
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# B3 - Living and Growing
What is meiosis?
cell division that results in 4 daughter cells each with half number of chromosomes of parent cell
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# B3 - Living and Growing
What does the Q₁₀ value show?
How much rate changes when temperature is raised by 10°C
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# B3 - Living and Growing
Where are stem cells found?
In early human embryos and in adults - but only in certain places, like bone marrow (aren’t as versatile as embryonic stem cells).
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# B3 - Living and Growing
What is old age?
Usually considered between age 65 and death.
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What are the moral and ethical issues on genetic engineering?
Some think is it wrong as it's for human benefit - animals suffer. People worry it won't stop, people will decide characteristics of their children. Evolutionary consequences not known so people think it is irresponsible because of impact on future generations.
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# B3 - Living and Growing
What is the optimum temperature of enzymes?
When reaction goes fastest just before it gets too hot and starts to denature. Most human enzymes have an optimum of 37°C
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# B3 - Living and Growing
DNA controls this. Protein synthesis. Section of DNA codes a particular protein (gene). Proteins are made up of chains of molecules (amino acids). Order of bases determines amino acid. 3 bases makes 1 amino acid - joined together to make protein.
How are proteins made?
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# B3 - Living and Growing
What is the word equation for aerobic respiration?
glucose + oxygen → carbon dioxide + water (+energy)
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# B3 - Living and Growing
Many plant cells keep ability to differentiate whereas animal cells lose that at an early age.
Why is cloning plants easier than animals?
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# B3 - Living and Growing
1) select best characteristic from existing stock 2) breed with each other 3) select best of offspring - breed together 4) continue process over several generations - desirable trait gets stronger and stronger.
What is the basic process of selective breeding?
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# B3 - Living and Growing
Meristems (tips of roots and shoots)
Where does cell division in plants occur?
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# B3 - Living and Growing
How are male gametes adapted for their function?
Small with long tails to swim. Lots of mitochondria to provide energy for swimming. Acrosome at front can release enzymes to digest through membrane of egg cell.
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# B3 - Living and Growing
What is the disadvantage of measuring length?
It doesn't tell you about change in width, diameter, number of branches etc.
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# B3 - Living and Growing
Small groups which make up strands of DNA. Each nucleotide contains a small molecule called a base.
What are nucleotides?
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# B3 - Living and Growing
What happens at the 4th stage of mitosis?
Cytoplasm divides and you get 2 new cells containing exact same genetic material.
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# B3 - Living and Growing
Drying out organism before weighing it.
What is involved in measuring dry mass?
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# B3 - Living and Growing
Measuring length or height of a plant/animal.
What is involved in measuring length?
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# B3 - Living and Growing
Permeable walls so substances can diffuse in and out. Walls usually only 1 cell thick - increases rate of diffusion because of shorter distance.
What do capillaries have?
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# B3 - Living and Growing
When does mitosis happen?
When you want identical cells e.g. grow or when you need to replace worn out cells and repair tissue.
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# B3 - Living and Growing
Adenine and Thymine (A and T), Guanine and Cytosine (G and C)
What are the complementary pairs of bases in DNA?
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When reaction goes fastest just before it gets too hot and starts to denature. Most human enzymes have an optimum of 37°C
What is the optimum temperature of enzymes?
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# B3 - Living and Growing
What is the advantage of measuring length?
Easy to measure.
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# B3 - Living and Growing
How do plants cells grow differently to animal cells?
Animals grow until a finite size (full growth) whereas plans grow continuously.
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# B3 - Living and Growing
More muscle because it has to pump blood around whole body whereas right ventricle only has to pump to lungs
Why does the left ventricle have a thicker wall?
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# B3 - Living and Growing
What process created dolly the sheep?
Nuclear transfer
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# B3 - Living and Growing
If too high/low, interferes with bonds holding enzyme together. Changes shape of active site and denatures enzyme. Optimum normally neutral pH7 but some exceptions.
How does the pH affect enzymes?
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# B3 - Living and Growing
Reactions involved in respiration.
What happens in the mitochondria?
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What is denaturing?
When it gets too hot, some bonds holding enzyme together break. Enzyme loses its shape, active site doesn't fit substrate - can't catalyse reaction and reaction stops. Enzyme can't function. Change in shape is irreversible.
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# B3 - Living and Growing
What is adolescence?
Begins with puberty and continues until body development and growth are complete. Rapid growth.
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# B3 - Living and Growing
Usually considered between age 65 and death.
What is old age?
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# B3 - Living and Growing
What do capillaries do?
Exchange materials at tissues. Supply food and oxygen. Remove carbon dioxide.
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# B3 - Living and Growing
Gene that causes resistance to frost damage, herbicides and disease can be cut and placed in a useful plant.
How has genetic engineering helped plants with resistance?
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# B3 - Living and Growing
Molecule which is changed in reaction.
What is the substrate?
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What are the disadvantages of selective breeding?
Reduces gene pool and inbreeding can cause health problems because increased risk of genetic disorders. A disease may also wipe them out because there is less variation and they are closely related.
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# B3 - Living and Growing
Each chromosome splits in half an 1 arm ends up in each new cell. 4 new cells (daughter cells) are made.
What is the 4th stage of meiosis?
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# B3 - Living and Growing
Why are organisms selectively bred?
To develop best features. Includes: maximum yield of meat, grain, milk etc, good health and disease resistance, and other qualities like temperament, speed and attractiveness.
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# B3 - Living and Growing
Plant chosen based on characteristics and several small pieces of tissue are removed from parent plant. Best results from root and shoot tips. Grow tissue in a growth medium containing nutrients and growth hormones under aseptic/sterile conditions. As tissues produce shoots and roots they are moved to potting compost to continue.
How are plants cloned?
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# B3 - Living and Growing
What are clones?
Genetically identical organisms
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# B3 - Living and Growing
What prevents back flow in the heart?
Semilunar, tricuspid and bicuspid valves
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# B3 - Living and Growing
cell division that results in 4 daughter cells each with half number of chromosomes of parent cell
What is meiosis?
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# B3 - Living and Growing
What is infancy?
Roughly first two years of life - rapid growth.
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# B3 - Living and Growing
What are the ethical issues with cloning?
Would have to be lots of surrogate pregnancies with high rate of miscarriage and stillbirths. Clones have often been unhealthy and died prematurely. It might be psychologically damaged by the knowledge it is a clone.
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# B3 - Living and Growing
Vitamin A can be a problem in these areas so scientists have taken a gene from beta-carotene production from carrots and put it into rice.
How has genetic engineering helped in countries which depend on rice?
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# B3 - Living and Growing
What is a mutation?
A change in DNA base sequence. Occurs within a gene.
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# B3 - Living and Growing
Long molecules of coiled up DNA
What are chromosomes?
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# B3 - Living and Growing
Rate at higher temperature ÷ rate at lower temperature
How can Q₁₀ be calculated?
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# B3 - Living and Growing
Early human embryos contain lots of stem cells and these can be extracted and grown. Eventually may be used to grow tissue to treat medical conditions like nerve damage, spinal injuries, skin cells, skin grafts.
What is stem celll therapy?
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# B3 - Living and Growing
Lungs
Where is deoxygenated blood pumped to?
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Rate doubles when temperature is rasied by 10°C
What does a Q₁₀ value of 2 mean?
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Why are red blood cells flexible?
So they can fit through capillaries easily.
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# B3 - Living and Growing
What are platelets?
Used in clotting blood.
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1) can mass produce animals with desirable characteristics. 2) human. Embryos could be produced by cloning adult body cells and embryos could supply stem cells which would reduce the risk of rejection
What are the benefits of cloning?
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# B3 - Living and Growing
When a cell reproduces itself by splitting to form 2 identical offspring.
What is mitosis?
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# B3 - Living and Growing
Where does cell division in plants occur?
Meristems (tips of roots and shoots)
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# B3 - Living and Growing
What can a mutation stop?
Production of protein gene normally codes for - or different protein produced instead.
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# B3 - Living and Growing
DNA coils into double-armed chromosomes. Arms are exact copies of each other - contain exactly same DNA.
What happens at the 2nd stage of mitosis?
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# B3 - Living and Growing
Who were the first to build a model of DNA?
Francis Crick and James Watson
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# B3 - Living and Growing
Chromosomes line up at centre of cell and divide as cell fibres pull them apart. 2 arms or each chromosome go to opposite poles of 1 cell. Membranes form around 2 sets of chromosomes.
What happens at the 3rd stage of mitosis?
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# B3 - Living and Growing
What are chromosomes?
Long molecules of coiled up DNA
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# B3 - Living and Growing
What are the 6 parts of a plant cell?
Nucleus, cell wall, cytoplasm, vacuole, chloroplasts, cell membrane.
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# B3 - Living and Growing
What are the two types of gene therapy?
1) involves changing body cells, particularly those cells most affected. Wouldn't affect gametes so offspring could still get it. 2) change cells in gametes so offspring won't be affected.
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# B3 - Living and Growing
When humans artificially select plants or animals they are going to breed and have their genes remain in population, according to what we want from them.
What is selective breeding?
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# B3 - Living and Growing
What does nuclear transfer involve?
Nucleus of egg cell removed so it had no genetic info. Another nucleus was inserted with all genetic info. Cell given electric shocks to divide by mitosis and embryo was implanted into surrogate mother until it is born.
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# B3 - Living and Growing
What is childhood?
Period between infancy and puberty. Steady growth.
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# B3 - Living and Growing
What are stem cells?
Undifferentiated cells which can develop into different types of cells, tissues and organs depending on instructions given.
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# B3 - Living and Growing
What are the 4 functions of proteins?
Enzymes - biological catalysts Carrier molecules - to transport smaller molecules Hormones - e.g. Insulin Structural proteins - physically strong e.g. Collagen
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# B3 - Living and Growing
Not affected by water in plant or by how much it's eaten.
What is the advantage of measuring dry mass?
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# B3 - Living and Growing
How are plants cloned?
Plant chosen based on characteristics and several small pieces of tissue are removed from parent plant. Best results from root and shoot tips. Grow tissue in a growth medium containing nutrients and growth hormones under aseptic/sterile conditions. As tissues produce shoots and roots they are moved to potting compost to continue.
