Nat 5 - Multicellular Organisms Flashcards

1
Q

Define the term multicellular organisms

A

Organisms that are made up of many cells

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2
Q

Describe the organisation of multicellular organisms

A

Multicellular organisms are organised into cells, tissues, organs and organ systems

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3
Q

Explain the significance of cell specialisation in multicellular organisms

A

It is very efficient as it ensures that cells do not have to carry out every function essential for the maintenance of life - they only carry out the function they’re specialised for, which saves energy.

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4
Q

Define the term stem cell

A

An unspecialised animal cell involved in growth and repair

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5
Q

State the type of organisms in which stem cells are found

A

Animals

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6
Q

Name two functions of stem cells in humans

A

Growth and repair

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7
Q

Define the term meristem

A

Site of production of non-specialised cells in plants and the only site of mitosis in the plant

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8
Q

State the type of organisms in which meristems are found

A

Plants

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9
Q

Name the process that occurs at a meristem

A

Cell division/mitosis

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10
Q

State the location of meristems

A

Shoot and root tips of plants

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11
Q

Describe the function of meristems

A

To carry out cell division to produce non-specialised cells

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12
Q

Name the components of the nervous system

A

Brain, spinal cord and nerves

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13
Q

Explain the function of the nervous system

A

To coordinate and control functions of the body

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14
Q

Name the components of the central nervous system

A

Brain and spinal cord

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15
Q

Name the three main parts of the brain

A

Cerebrum, cerebellum and medulla

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16
Q

Describe the function of each part of the brain

A

Cerebrum - memory and reasoning
Cerebellum - balance and muscle contraction
Medulla - breathing and heart rate

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17
Q

Name the three types of neurons

A

Sensory neuron, relay neuron and motor neuron

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18
Q

Describe the function of each type of neuron

A

Sensory - passes information to the CNS
Relay - passes information from sensory to motor
Motor - enables a response to occur by passing information to the effector

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19
Q

State the type of message that is passed through the nervous system

A

Electrical signal

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20
Q

State the speed of transmission of a nerve impulse

A

Very fast

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21
Q

Define the term receptor

A

A receptor detects changes in the environment called stimuli

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22
Q

Define the term effector and give two examples

A

An effector carries out the response to a stimulus. Examples of effectors are muscles and glands

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23
Q

Define the term synapse

A

The gap between two neurons

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24
Q

Describe how information is passed across a synapse

A

A chemical transmitter is released which diffuses across the gap

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25
Q

Describe how impulses are transferred in a reflex arc

A

Through neurons

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26
Q

Give two examples of reflex actions

A

Coughing
Pulling hand away from heat
Knee jerk reflex

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27
Q

Explain the importance of reflex actions

A

To protect the body from harm

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28
Q

Define the term hormone

A

A chemical messenger

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29
Q

Name the glands that release hormones

A

Endocrine glands

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30
Q

State how hormones travel around the body

A

In the bloodstream

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31
Q

Compare the speed of communication in hormone to the speed of nerve impulses

A

The speed of communication in hormones is much slower than the speed of nerve impulses

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32
Q

Explain why only target tissues/organs are affected by specific hormones

A

Target tissues/organs have protein receptors that pick up the signal from a hormone. Only certain tissues/organs are affected by each hormone because only certain tissues/organs have these receptors

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33
Q

State the function of insulin

A

It controls and regulates glucose levels in the blood

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34
Q

Describe the conditions necessary for insulin to be released

A

High blood glucose levels

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35
Q

State the name of the organ that releases insulin

A

Pancreas

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36
Q

Describe the effect that insulin has on blood glucose levels

A

It lowers blood glucose levels back down to normal

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37
Q

Name the storage carbohydrate in humans and state the location in which it can be stored

A

Glycogen - stored in the liver

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38
Q

State the function of glucagon

A

It controls and regulates glucose levels in the blood

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39
Q

Describe the conditions necessary for glucose to be released

A

Low blood glucose levels

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40
Q

State the name of the organ that releases glucagon

A

Pancreas

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41
Q

Describe the effect that glucagon has on blood glucose levels

A

It increases blood glucose levels back to normal

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42
Q

Define the term gamete

A

Sex cell

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43
Q

Name the female gamete in plants and animals

A

Animals - egg

Plants - ovule

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44
Q

Name the male gamete in plants and animals

A

Animals - sperm

Plants - pollen

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45
Q

Name the site of production of each type of gamete

A

Sperm - produced in testes
Egg - produced in ovary
Pollen - produced in anther
Ovule - produced in ovary

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46
Q

Define the term diploid

A

Containing two sets of chromosomes

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47
Q

Name four examples of diploid cells

A

Liver cell, kidney cell, skin cell and a zygote

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48
Q

Define the term haploid

A

Containing one set of chromosomes

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49
Q

Define the term fertilisation in animals

A

When the nucleus of the sperm fuses with the nucleus of the egg

50
Q

Define the term zygote

A

The diploid cell formed as a result of fertilisation

51
Q

Define the term chromosome complement

A

The whole set of chromosomes for a species e.g. The chromosome complement for humans is 46 (including sex cells)

52
Q

Define the term variation

A

The differences that exist between species within a population

53
Q

Describe how variation is increased in organisms

A

By combining genes from desperate parents

54
Q

Define the term fertilisation in plants

A

When the nucleus of the pollen fuses with the nucleus of the ovule

55
Q

Define the term discrete variation

A

Variation for characteristics that fall into distinct groups and are usually observed

56
Q

Give three examples of discrete variation

A

Eye colour, blood type, ear lobe type

57
Q

State the number of genes that give rise to discrete characteristics

A

One

58
Q

Define the term continuous variation

A

Variation for characteristics that have a wide range of values and are usually measured

59
Q

Give three examples of continuous variation

A

Height, weight and length of foot

60
Q

Define the term polygenic

A

Controlled by lots of genes

61
Q

State which type of variation is the most common in the phenotype of organisms

A

Continuous variation

62
Q

Define the term allele

A

Different forms of a gene e.g. Blue and brown are different forms of the eye colour gene

63
Q

Define the term genotype

A

The combination of genes an individual has

64
Q

Define the term phenotype

A

The appearance of an individual based on its genes/visible characteristics

65
Q

Define the term dominant

A

The allele that is seen in the phenotype

66
Q

Define the term recessive

A

The allele that is masked by the dominant in the phenotype

67
Q

Define the term homozygous

A

Two of the same alleles in a genotype

68
Q

Define the term heterozygous

A

Two different alleles in a genotype

69
Q

Define the terms P, F1 and F2 generations

A

P - parent generation
F1 - first generation of offspring after the parents
F2 - generation produced when the F1 is crossed

70
Q

Explain why actual phenotype ratio differs from expected phenotype ratio

A

Fertilisation is a random process

71
Q

Name the process by which water enters the plant

A

Osmosis

72
Q

Name the cells that absorb water in the plant

A

Root hair cells

73
Q

Name the vessel that transports water and minerals

A

Xylem vessels

74
Q

Name the material that supports xylem vessels

A

Lignin

75
Q

State if xylem vessels are living or non-living

A

Non-living

76
Q

Explain why water needs to be transported by the plant

A

It is the raw material used for photosynthesis

77
Q

Define the term transpiration

A

The loss of water through the leaves

78
Q

Name the leaf structure that allows water loss from the plant and state its location

A

Stomata - located in small pores of the leaf in plants

79
Q

Describe how the stomata is opened and closed

A

Guard cells

80
Q

Name the process that allows water to escape from the plant

A

Evaporation

81
Q

Name the vessels that transport sugar in the plant

A

Phloem vessels

82
Q

State the direction of transport of sugar

A

Upwards and downwards (to supply all the cells with energy)

83
Q

State if phloem vessels are living or non-living

A

Living

84
Q

Name three substances that are transported in the blood in animals

A

Glucose, oxygen and carbon dioxide

85
Q

State the function of the heart

A

The main function of the heart is to pump blood to the lungs to become oxygenated blood and to supply the rest of the body with oxygenated blood

86
Q

Name the four chambers in the heart

A

Right atrium, right ventricles, left atrium and left ventricle

87
Q

State the location of valves in the heart

A

Two valves are situated between the atria and the ventricles. The other two are situated between the ventricles and the two arteries that leave the heart

88
Q

Explain the importance of valves in the heart

A

To prevent back flow of blood

89
Q

Define the term oxygenated blood

A

Blood is is full of oxygen from the lungs

90
Q

Define the term deoxygenated

A

Blood that has had most of its oxygen removed

91
Q

Describe the function of the aorta

A

It carries blood oxygenated bloody from the left ventricle to the body

92
Q

Describe the function of the vena cava

A

It carries deoxygenated blood from the body to the right atrium

93
Q

Describe the function of the pulmonary artery

A

It carries deoxygenated blood from the right ventricle to the lungs

94
Q

Describe the function of the pulmonary vein

A

It carries oxygenated blood from the lungs to the left atrium

95
Q

Describe the pathway of blood as it travels through the heart and associated blood vessels

A

Blood flows from the right atrium to the right ventricle, up through the pulmonary artery to the lungs. Blood then travels through the pulmonary vein to the left atrium, then to the left ventricle and out the aorta to the body. Blood then travels through the vena cava back to the right atrium.

96
Q

Name the blood vessels that supply the heart muscle with blood

A

Coronary arteries

97
Q

Name the three types of blood vessels

A

Arteries, veins and capillaries

98
Q

State the function of each of the three blood vessels

A

Artery - to carry blood at high pressure away from the heart
Vein - to carry blood under low pressure back into the heart
Capillary - to exchange materials

99
Q

Compare the structure of each of the three blood vessels

A

Artery - thick walls, narrow central channel
Vein - thin walls, wide central channel, contains valves
Capillary - thin walls, large surface area, in close contact with living cells in tissues and organs

100
Q

Describe two features of capillaries that make them efficient at their job

A

They have thin walls and a large surface area (they are also in close contact with living cells in tissues and organs) for exchange of materials

101
Q

Describe the function of red blood cells

A

To carry oxygen around the body

102
Q

Describe three ways in which the structure of red blood cells relates to their function

A

They contain haemoglobin which sticks to oxygen molecules. They have a biconcave which allows them to travel through small blood vessels to provide a large surface area for exchange of materials

103
Q

State the function of cartilage in the respiratory system

A

To keep the airways open

104
Q

Name the two gases that are exchanged in the alveoli

A

Oxygen and carbon dioxide

105
Q

State three features of alveoli that make them efficient at gas exchange

A

Thin walls, large surface area and rich blood supply

106
Q

Describe the function of mucus and cilia in the respiratory system

A

The mucus traps any dirt and bacteria in the trachea and the cilia sweeps mucus containing trapped dirt and bacteria up and away from the lungs

107
Q

Describe the process of peristalsis

A

The movement of food through the digestive system. Muscles behind the food are contracted and muscles in front of the food are relaxed/expanded

108
Q

Describe the process that occurs in the small intestine

A

Absorption of soluble products of digestion go into the bloodstream

109
Q

Describe the features of a villi that make them efficient at absorption

A

They are thin walled (one cell thick) so that soluble products can pass through rapidly. They have a large surface area and a rich blood supply for absorption of glucose and amino acids. They also have a lacteal for absorption of fatty acids and glycerol

110
Q

Name the structure that absorbs fatty acids and glycerol

A

Central lacteal (in the villi)

111
Q

Name the structure that absorbs glucose and amino acids

A

Blood capillaries (in the villi)

112
Q

Name five examples of lifestyle choices that can affect the transport system in humans

A

High fat diet, high salt diet, lack of exercise, use of tobacco, use of alcohol or stress

113
Q

Name three examples of conditions that can arise if humans make poor lifestyle choices

A

Diabetes, heart attacks, strokes, fatty deposits in blood vessels, blood clots, unhealthy levels of stress

114
Q

Describe the function of the small vein

A

It contains the xylem and phloem

115
Q

Describe the function of the mesophyll

A

Layers of green cells which take in carbon dioxide during photosynthesis

116
Q

Describe the function of the stomata

A

Pores in the lower leaf which allow entry of carbon dioxide and exit of oxygen

117
Q

Describe the function of guard cells

A

Pairs of cells which control the opening and closing of the stomata

118
Q

Explain how water up the roots, stem and to the leaf

A

Water moves into the root hair cells by osmosis. Water then travels upwards in the xylem. Water then travels to the stomata in the leaf and evaporates out.

119
Q

Describe how wind affects transpiration

A

It increases the rate of transpiration. The air outside of the stomata is constantly replaced with drier air.

120
Q

Describe how humidity affects the rate of transpiration

A

It decreases the rate of transpiration. Lots of water vapour in the air, less water lost through the stomata

121
Q

Describe the function of the capillaries

A

To exchange gases, nutrients and waste

122
Q

Describe the function of the upper epidermis

A

It is a protective layer which lets light through