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KS3 biology revision Flashcards

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Biology 101 flashcards
1
Q

After fertilisation where is the embryo implanted?

A

The lining of the uterus

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2
Q

What is the life cycle?

A

Zygote, embryo, foetus, baby, toddler, child, adolescent,

adult

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3
Q

What does the placenta do?

A

Gets food and oxygen from the mothers blood

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4
Q

How does the food and oxygen travel to the foetus?

A

Through blood vessels in the umbilical cord

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5
Q

What is the foetus protected by and where is it held?

A

It is protected by amniotic fluid and held in the amnion

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6
Q

What happens to boys during puberty?

A

Voices break, hair grows on face and chest and testes they start to produce sperm cells.

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7
Q

What happens to girls during puberty?

A

Develop breasts and the menstrual cycle begins.

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8
Q

Who/what is pollen carried by?

A

By animals (usually insects) or the wind

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9
Q

How is pollen carried?

A

It is carried from the anthers of one flower to the stigma of other

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10
Q

What is seed dispersal?

A

The fruits carry the seeds to new areas

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11
Q

Define germination

A

The growth of a plant

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12
Q

Explain the parts of a dandelion flower

A

Pollen grains, stigma, pollen tube style, ovary, ovule, egg cell

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13
Q

Where is the pollen tube in the flower?

A

Down the style of each flower and into the ovule

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14
Q

What happens in the ovule of a plant?

A

The male gamete (inside the pollen grain) fertilises and egg cell

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15
Q

What does a balanced diet mean?

A

Eating the right amount of different nutrients

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16
Q

What are examples of carbohydrates (not actual food) and what are they needed for?

A

Sugars and starch for energy

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17
Q

What are proteins needed for?

A

Growth and repair

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18
Q

What are examples of lipids (not actual food) and what are they needed for?

A

Fats and oils for energy storage and insulation

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19
Q

What are vitamins and minerals needed for?

A

For health

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20
Q

What is fibre needed for?

A

To keep intestines clean and working properly

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21
Q

What is water needed for?

A

To helps cells hold their shape and to dissolve substances

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22
Q

What does too much or too little of nutrition cause and what are some examples?

A

Malnutrition. Obesity and deficiency diseases such as scurvy

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23
Q

What is energy measured in?

A

Kilo joules

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24
Q

Who needs the most energy?

A

Active people and those who are growing

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25
Q

What is the digestive system made up of?

A

Lots of different organs such as the gut, liver and salivary glands

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26
Q

How is food pushed through the gut?

A

Muscles contract behind the food which squeezes it along.

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27
Q

What happens when the food is pushed through the gut?

A

Nutrients are broken down into small soluble molecules by biological catalysts called enzymes. Soluble nutrients are then absorbed into the blood.

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28
Q

What does gut bacteria do?

A

Helps to break down some foods and produce useful substances such as vitamins.

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29
Q

How are proteins digested?

A

By the enzymes in the stomach and the small intestine.

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30
Q

How are vitamins and minerals digested?`

A

They do not need to be digested as they are already soluble

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31
Q

How is fibre digested?

A

It is not digested but stored as faeces in the rectum and egested (eliminated) by the anus

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32
Q

What does the large intestine do?

A

It removes the water from the undigested food

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33
Q

What does the small intestine do?

A

Digested food is absorbed through the walls which has folds (villi and the microvilli) to increase surface area.

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34
Q

What does the cell nuclei contain?`

A

Genetic information

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35
Q

What does the genetic information do?

A

Controls cells and many characteristics of whole organisms

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36
Q

What is hereditary?

A

Passing genetic information from parents to offspring

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37
Q

What happens to genetic information when the offspring is reproduced asexually?

A

The contain the same genetic information as their parent as there is only one parent, so they are identical.

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38
Q

What happens to genetic information when the offspring is reproduced sexually?

A

They have characteristics from both parents as there are 46 chromosomes and they inherit 23 chromosomes from each parent.

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39
Q

What are chromosomes made of?

A

A molecule of DNA

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40
Q

Where is genetic information stored?

A

Genes (sections of the DNA)

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41
Q

What is a shape of the DNA molecule?

A

Double helix

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42
Q

Who and when worked out the shape of DNA?

A

James Watson and Francis Crick in 1950

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43
Q

Who took x-ray pictures of the DNA?

A

Rosalind Franklin and Maurice Wilkins

44
Q

What is a species?

A

A group of organisms that reproduce sexually with one another to produce more organisms of the same type

45
Q

What is environmental variation?

A

the ability of an organism to alter greatly its phenotype depending upon environmental conditions

46
Q

What is genetic variation?

A

Genetic variation is the difference in DNA among individuals or the differences between populations.

47
Q

What is continuous variation?

A

Variation that can be spread across a scale e.g height

48
Q

What is discontinuous variation?

A

Can only have certain values e.g shoe size

49
Q

What is biodiversity?

A

The variety of plant and animal life in the world or in a particular habitat, a high level of which is usually considered to be important and desirable.

50
Q

Why do we need to preserve biodiversity?

A
  • organisms depend on one another
  • areas with greater biodiversity recover faster from disasters
  • there are many undiscovered substances in organisms that could be useful to us (for food, medicines)
51
Q

What are the ways of preserving biodiversity?

A
  • Protecting habitats
  • Cutting down pollution
  • Encouraging farmers to plant a wide variety of crops
52
Q

What does tar in cigarettes do?

A

It coats the alveoli and then reduces the speed of gas exchange

53
Q

What does tar in cigarettes do in the long term?

A

It causes the alveoli the break apart (emphysema) which reduces their surface area

54
Q

What damage does carbon monoxide cause in the body from cigarette smoke?

A

It sticks to haemoglobin in red blood cells and stops them carrying so much oxygen.

55
Q

What does nicotine do to the body?

A

It makes the arteries narrower

56
Q

What does carbon monoxide do to pregnant women?

A

Can make them have a premature birth

57
Q

What are the short term affects of alcohol?

A

Vomiting

58
Q

Give two examples of depressants.

A

Vodka and heroin

59
Q

Give two examples of stimulants.

A

Caffeine and ecstasy

60
Q

What do stimulants do?

A

Increase the speed with which the impulses travel through the nervous system.

61
Q

What do depressants do?

A

Slow the impulses that travel through the nervous system

62
Q

What does the cytoplasm do?

A

Where chemical reactions happen

63
Q

What does the nucleus do?

A

Contains DNA, controls the cell

64
Q

What does the cell membrane do?

A

Controls what goes in and out of the cell

65
Q

What does the mitochondria do?

A

Where aerobic respiration happens

66
Q

What features are there in a plant cell?

A

Cytoplasm, nucleus, cell membrane, mitochondria, cell wall, vacuole, chloroplasts

67
Q

What does the cell wall do?

A

Made from cellulose fibres and strengthens the cell and supports the plant.

68
Q

What does the vacuole do?

A

Filled with cell sap to help keep the cell turgid.

69
Q

What does the chloroplast do?

A

Organelles that contains the green pigment, chlorophyll, which absorbs light energy for photosynthesis. Contains the enzymes needed for photosynthesis

70
Q

What is the word equation of aerobic respiration for humans?

A

glucose + oxygen → carbon dioxide + water

71
Q

What is the word equation of anaerobic respiration for humans?

A

glucose → lactic acid + energy released

72
Q

What is the word equation of anaerobic respiration for yeast?

A

glucose → ethanol + carbon dioxide + energy released

73
Q

What is the word equation for photosynthesis?

A

(Chlorophyll)
Carbon dioxide+Water = Oxygen+Glucose
(Oxygen)

74
Q

What are examples of specialised cells?

A

Sperm cell, root hair cell, ciliated cell, nerve cell

75
Q

How are sperm cells adapted for their function?

A

They have tails that allow them to swim and it is also streamlined body to them to move more quickly.

76
Q

How are root hair cells adapted for their function?

A

For taking up water and mineral ions by having a large surface area to increase the rate of absorption.

77
Q

How are nerve cells adapted for their function?

A

They are adapted to carry electrical impulses from one place to another: they have a long fibre (axon) which is insulated by a fatty sheath.

78
Q

How are ciliated cells adapted for their function?

A

Ciliated cells are adapted in the respiratory tract to form an epithelial lining of coordinated metachronal ciliary activity that provides the propelling force for the transport of mucus along the airways.

79
Q

What is diffusion?

A

Substances move from a high to a lower concentration down a concentration gradient.

80
Q

What is osmosis?

A

Water moves from a high to a lower concentration across a partially permeable membrane and down a concentration gradient

81
Q

Why is surface area: volume ratio important for diffusion and osmosis?

A

By reducing cell size, cells are greatly increasing the surface area to volume ratio which makes diffusion/osmosis much more effective.

82
Q

Define cell

A

The smallest structural and functional unit of an organism, which is typically microscopic and consists of cytoplasm and a nucleus enclosed in a membrane.

83
Q

Define tissue

A

A group of cells with a similar structure, organised to carry out specific functions.

84
Q

Define organ

A

A collection of tissues that structurally form a functional unit specialised to perform a particular function. Your heart, kidneys, and lungs are examples of organs.

85
Q

Define organism

A

In biology, an organism is any individual contiguous system that embodies the properties of life. It is a synonym for “life form”.

86
Q

Define organ system

A

An organ system is a group of organs that work together as a biological system to perform one or more functions.

87
Q

Name some organs systems

A

Nervous system, musculoskeletal system, respiratory system, reproductive system, digestive system

88
Q

What do plant gas exchange go through?

A

The stomata in their leaves

89
Q

What are stomata and how can they be opened?

A

Small holes in the leaves that can be opened and closed by guard cells.

90
Q

What happens when the stomata are open?

A

Gases can diffuse between the outside of the leaf and the inside spaces of the leaf.

91
Q

Why is the leaf flat?

A

To give a large surface area to trap light

92
Q

What are palisade cells full of?

A

Chloroplasts

93
Q

What carries the water throughout the leaf?

A

Xylem tissue

94
Q

What carries the sugar away from the leaf?

A

Phloem tissue

95
Q

What exits the leaf through the stomata?

A

Oxygen and water vapour

96
Q

What enters the leaf through the stomata?

A

Carbon dioxide

97
Q

How can you measure the force exerted by an antagonist muscle pair as it contracts?

A

Put a newton meter to the fingers

98
Q

What happens during inhalation?

A

Muscles in the diaphragm and between the ribs contract. The diaphragm moves down and the ribs move up and outward. This increases the size of the chest and so the pressure inside it drops. Pressure in the lungs is reduced, so atmospheric pressure pushes air in.

99
Q

What happens during exhalation?

A

Muscles in the diaphragm and between the ribs relax. This reduces the size of the chest and so the pressure inside it rises. Pressure in the lungs is increased, so air is pushed out.

100
Q

What is an air sac made from?

A

Network of capillaries

101
Q

What are the features of capillaries?

A

Plasma and red blood cells

102
Q

What was the overall movement of carbon dioxide in capillaries?

A

Out of the capillaries

103
Q

What was the overall movement of oxygen in capillaries?

A

Into the capillaries

104
Q

What are the features of the male reproductive system?

A

Bladder, glands, urethra, sperm duct, testes, foreskin, scrotum

105
Q

What are the features of the female reproductive system?

A

Ovaries, oviducts, placenta, umbilical cord, uterus, bladder, cervix, vagina

106
Q

What are the seven life processes? (MRS GREN)

A

movement, respiration, sensitivity, growth, reproduction, excretion and nutrition

Science (5 decks)

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