National 5 Biology Exam Flashcards
(127 cards)
1
Q
Animal cells left in a solution with a lower water concentration than their contents will…
A
Shrink
2
Q
Animal cells left in a solution with a higher water concentration than their contents will…
A
Burst
3
Q
Plant cells left in a solution with a lower water concentration than their contents will…
A
Become plasmolysed
4
Q
Plant cells left in a solution with a higher water concentration than their contents will…
A
Become turgid
5
Q
Where does the 1st stage of protein production occur in a cell?
A
Nucleus
6
Q
Where does the 2nd stage of protein production occur in a cell
A
Ribosome
7
Q
State 4 cellular activities that require ATP
A
- Muscle cell contraction
- Cell division
- Transmission of nerve impulses
- Protein synthesis
8
Q
Does stage 1 of aerobic respiration require oxygen?
A
No
9
Q
Does stage 2 of aerobic respiration require oxygen?
A
Yes
10
Q
Where does stage 1 of aerobic respiration occur?
A
Cytoplasm
11
Q
Where does stage 2 of aerobic respiration occur?
A
Mitochondria
12
Q
Where does fermentation occur?
A
Cytoplasm
13
Q
Is oxygen present during fermentation?
A
No
14
Q
Is fermentation in animal cells a reversible process?
A
Yes, when oxygen becomes available
15
Q
Is fermentation in plant and yeast cells a reversible process?
A
No
16
Q
State the fermentation equation in animal cells
A
Glucose -> Pyruvate -> Lactic acid
17
Q
State the fermentation equation in plant and yeast cells
A
Glucose -> Pyruvate -> CO2 + Ethanol
18
Q
Explain why muscle cells require more mitochondria than skin cells
A
Requires a lot of ATP for movement
19
Q
Describe the fermentation pathway in muscle cells
A
Glucose converted into pyruvate. Pyruvate converted into lactic acid. ATP produced
20
Q
Explain why at 60°C respiration stopped occurring
A
Respiration is an enzyme controlled reaction and enzymes become denatured at 60°C
21
Q
Suggest why some cells need more mitochondria
A
They have higher energy requirements
22
Q
Name the substance of which enzymes are made
A
Amino acids
23
Q
Explain the role of enzymes in living cells
A
Speeds up reactions
24
Q
Name the reaction when enzymes break down large molecules to small molecules
A
Degradation reaction
25
Name the reaction when enzymes build down small molecules to large molecules
Synthesis reaction
26
Name the substance upon which an enzyme acts
Substrate
27
Name the substance produced as a result of the reaction
Product
28
Describe the events of a degradation reaction
Enzyme and substrate join together. Reaction occurs at active site of the
enzyme. Two smaller products are
formed
29
Describe the events of a synthesis reaction
Enzyme and substrates join together. Reaction occurs at active site of the
enzyme. One larger product is
formed
30
Describe the feature of enzymes that allows it to bind to only one substrate
The active site of the enzyme is
complementary to the substrate
31
Give a reason why the rate of reaction will be affected by an enzyme becoming denatured
The active site changes shape
32
Describe the way in which DNA codes differs from person to person
Sequence of bases are different
33
Name the single stranded molecule which carries a complementary copy of the code from the DNA in the nucleus to the ribosome for protein synthesis
mRNA
34
Name the 4 bases
- Adenine
- Thymine
- Cytosine
- Guanine
35
What is the cell membrane composed of?
Proteins and phospholipids
36
What does the cell membrane allow to pass through?
Small molecules such as oxygen and glucose
37
What does the cell membrane stop passing through?
Protein and starch
38
What is the movement of molecules from a higher concentration to a lower concentration?
Passive transport
39
Does passive transport require energy?
No
40
State an example of passive transport using non water molecules
Diffusion
41
State an example of passive transport using water molecules
Osmosis
42
What is the movement of molecules from a lower concentration to a higher concentration?
Active transport
43
Does active transport require energy?
Yes
44
What is responsible for moving substances across the cell membrane?
Proteins
45
State a feature of the cell membrane which allows the movement of only
some substances into the cell
It's selectively permeable
46
Explain why animal cells and plant cells don't produce the same results when placed in a solution of the same concentration
Plant cells have a cell wall and a cell wall prevents cells from bursting/shrinking
47
Give the term which describes the structure of a DNA molecule
Double-stranded helix
48
Describe the way in which the DNA strands are linked together
Complementary bases
49
Define stem cells
Unspecialised cells which can divide to self-renew or divide into different types of specialised cells
50
What are stem cells essential for?
Growth and repair
51
What are the 2 types of stem cells?
Embryonic and tissue
52
What process results in new cells being produced?
Cell division or mitosis
53
Describe the process of mitosis
Chromosome line up along the equator. Spindle fibres form and pairs of chromatids are pulled apart. Chromosomes move to
opposite poles of the cell. Cytoplasm divides, forming 2 daughter cells
54
State the specialisation hierarchy
Specialised cell -> Tissue -> Organ -> System -> Organism
55
Explain why a hormone only affects its target cells
They have receptors and these are specific to this hormone
56
Name the type of gland that releases hormones into the bloodstream
Endocrine glands
57
Name the part of the brain which controls balance and movement
Cerebellum
58
Name the part of the brain which controls conscious thoughts and memory
Cerebrum
59
Name the part of the brain which controls heart and breathing rate
Medulla
60
Doctors touched a patient's skin with a needle. Describe how the stimulus is detected at the skin and how the message is then carried into and across the spinal cord
Detected by receptors. Sent by electrical impulse from sensory to relay neuron across synapse
61
Name the organ which produces insulin
Pancreas
62
Explain why a person suffering from diabetes might show extreme tiredness
Glucose is needed to release energy
63
Name the structures found on the surface of the target tissues that
respond to the hormone insulin
Receptor
64
Describe how blood glucose is returned from low to normal levels in the human body
Pancreas releases glucagon which travels in the blood to the liver. Glycogen is converted into glucose
65
State how messages are transferred at a synapse
Chemicals
66
State the function of a reflex
Protect the body from harm
67
Describe how blood glucose is returned from high to normal levels in the human body
Pancreas releases insulin which travels in the blood to the liver. Glucose is converted into glucose.
68
Name the organ which produces glucagon
Pancreas
69
Name the organ that produces sperm
Testes
70
Name the organ that produces eggs
Ovary
71
Describe what happens during fertilisation
Sperm nucleus and egg nucleus fuse
together
72
Name the cell which is produced when the sperm fertilises the egg
Zygote
73
What is the site of fertilisation
Oviduct
74
Name is the male gamete in plants
Pollen
75
Name the female gamete in plants
Ovules
76
Name the organ that produces pollen
Anther
77
Name the organ that produces ovules
Ovary
78
Name the chemical messengers carried from one part of the human body to another in the blood
Hormones
79
Describe discrete variation
A characteristic where measurements fall into distinct groups, like writing hand
80
Describe continuous variation
A characteristic with a range of values between a min and max, like height
81
What are discrete characteristics controlled by?
Single gene inheritance
82
What are continuous characteristics controlled by?
Several genes, polygenic inheritance
83
Define the term homozygous
Same alleles
84
Define the term heterozygous
Different alleles
85
Explain why the expected phenotype ratio be different to the actual phenotype ratio?
Fertilisation is a random process
86
Describe the affect of an increase in humidity on rate of transpiration
Decrease
87
Describe the affect of an increase in temperature on rate of transpiration
Increase
87
Describe the affect of an increase in wind speed on rate of transpiration
Increase
88
Describe how the affect of wind speed could be investigated
Use a fan beside the apparatus
89
Describe how the affect of temperature could be investigated
Put a heater beside the apparatus
90
Suggest an advantage of having fewer stomata
Plant will not require as much water
91
State the function of the palisade mesophyll
Main site of photosynthesis
92
State the function of the stoma
Site of gas exchange
93
State the function of the lower epidermis
Contains stomata
94
State the function of the spongy mesophyll
Site of photosynthesis with air spaces to allow gas to circulate
95
State the function of the leaf vein
Transports water and sugar
96
State the function of the waxy cuticle
Waterproof layer
97
State the function of the guard cell
Controls the opening and closing of the stomata
98
State the function of the upper epidermis
Protective, colourless layer that allows light to pass through
99
Suggest an advantage of having the palisade mesophyll near the upper surface of the plant
To absorb more light
100
Describe a structural feature of the xylem
Lignin which allows the plant to withstand pressure change due to water movement
101
Describe a structural feature of the phloem
Sieve plates which allow for sugar movement
102
Name the process responsible for the movement of water and its evaporation from the leafy shoot
Transpiration
103
Name the process by which oxygen moves out of the leaf through
stomata.
Diffusion
104
Name a substance that enters the leaf through stomata
CO2
105
Name 2 substances that sugar could be converted into
Starch and cellulose
106
Name the chemical in cells of producers that traps light energy
Chlorophyll
107
State the meaning of the term producer
An organism that makes its own food
108
Describe what is meant by the term ecosystem
All the organisms and the non-living components
109
State the definition of the term mutation
A random change to the genetic material of an organism
110
State the term given to microorganisms like bacteria that cause disease
Pathogens
111
Name the organelle present in leaf cells where stage 1 of photosynthesis takes place
Chloroplasts
112
Why is a valve essential in the heart
Prevents blood flowing back when the heart beats
113
Describe how messages travel along an inter neuron and are then transferred from the inter neuron to a motor neuron
Along the neuron electrical impulses. Chemical transfer the messages between the neurons
114
Name the part of the body where the inter neuron is found
Spinal cord
115
Explain what is meant by the term diploid
Has two sets of chromosomes
116
Describe the stages of muscle production in a cell
A complementary copy of the section of DNA is made. mRNA carries the code from the nucleus to the ribosome where proteins are formed from amino acids.
117
State the meaning of the term niche
Role an organism plays within a community
118
State the meaning of the term biodiversity
The range of species or variation that exist among living things
119
Name 3 biotic factors
Disease, predation, grazing
120
Name 3 abiotic factors
pH, temperature, light intensity
121
State the meaning of the term indicator species
Species that, by their presence or absence, indicate pollution levels
122
Where does photosynthesis occur
Chloroplasts
123
What is used to define the introduction of a natural predator to reduce pest population
Biological control
124
What environment factors increase the rate of mutations
Radiation
125
State the meaning of the term speciation
The formation of a new species
126
Name 3 isolation barriers
Geographical, ecological, behavioural
