Topic 1 - Key Concepts in Biology Flashcards Preview

Edexcel GCSE Biology > Topic 1 - Key Concepts in Biology > Flashcards

Flashcards in Topic 1 - Key Concepts in Biology Deck (87):
1

What does a microscope do?

Makes small objects appear larger/magnifies small objects

2

What part of a microscope do you look through?

eyepiece lens

3

Which part of a microscope do you use to get a clear image?

the focusing wheel

4

If an average height person in Year 10 is magnified 600 times, how tall will they be compared to the tallest building in the world, which is 828 m tall?

about the same height; the Burj Khalifa, Dubai is 828 m tall

5

Put these in order of size, biggest first: atom, animal cell, cell nucleus, muscle tissue, protein molecule, water molecule

muscle tissue, animal cell, cell nucleus, protein molecule, water molecule, atom

6

A microscope has a ×5 eyepiece lens and a ×5 objective lens. What is the total magnification?

×25; 5 × 5 = 25

7

A human hair has a width of 100 μm but appears 20 mm wide in a photo. What magnification is the photo?

×200; 20 mm = 20 000 μm; 20 000 ÷ 100 = 200

8

How many millimetres are there in a metre?

1000

9

What unit is 1000 times smaller than a millimetre?

micrometre, μm

10

What is the unit symbol for a nanometre?

nm

11

What is an estimation?

an approximate value

12

Name one part you could find in a plant cell but not an animal cell.

cell wall, chloroplasts, permanent vacuole

13

What process happens in a mitochondrion?

aerobic respiration

14

What is one function of a plant cell’s permanent vacuole?

to help keep the cell rigid/to store substances

15

In which part of a plant cell is cell sap stored?

vacuole

16

In which part of a cell would you find chromosomes?

Nucleus

17

When you look down a microscope, what is the area that you see called?

field of view

18

Why can an electron microscope detect smaller structures in cells than a light microscope?

it has better magnification and better resolution

19

What is a picture taken with a microscope called?

micrograph

20

Some microscope pictures have a small line drawn on them with information about how long the line is when unmagnified. What is this line called?

scale bar

21

List three sub-cellular structures that are usually found in animal cells.

any three from: cell membrane, nucleus, mitochondria,

22

List three sub-cellular structures found in plant cells but not in animal cells.

large permanent vacuole, chloroplasts, cell wall

23

Which cell structure controls what enters and leaves the cell?

cell membrane

24

Which cell structure controls how the cell works?

nucleus

25

In which cell structure does respiration mainly take place?

Mitochondria

26

Which plant cell structure contains chlorophyll?

Chloroplast

27

What is the function of the cell structure that contains chlorophyll?

to capture energy from light for photosynthesis/to produce glucose using photosynthesis

28

Describe the function of the structure that surrounds plant cells, but not animal cells.

supports and protects the cell

29

What is the function of ribosomes?

manufacture of proteins

30

What are gametes?

Sex cells

31

A bacterium is 20 μm long. How long is it in metres?

0.00002 m

32

A bacterium is 5 μm wide. How wide is it in nanometres?

500 nm

33

What part of an animal cell controls the cell’s activities?

Nucleus

34

What do ribosomes make?

Proteins

35

Name one part that a plant cell might have but an animal cell would not.

chloroplast, permanent large vacuole, cell wall

36

What do bacteria use to move themselves?

flagella

37

Animal and plant cells are eukaryotic. What word describes bacterial cells?

Prokaryotic

38

Name one structure that an animal cell would have but a bacterial cell would not.

nucleus, mitochondria

39

What is this format for numbers called: A × 10n?

Standard form

40

What is 1 × 106 m written as an ordinary number?

1 000 000 m

41

Name two substances that might be found in the cytoplasm of an egg cell to provide energy.

carbohydrate or starch, lipid or fat or oil

42

Egg cells also contain protein. Which cell structure makes proteins?

ribosome

43

In which system of the body is food broken down?

digestive system

44

Why do we need to break food down?

because the molecules in food are too large to cross cell membranes

45

In which organ of the body is digested food absorbed?

small intestine

46

Which group of molecules help to digest food?

Enzymes

47

Give one example of the group of molecules that you named in the previous question.

any suitable example, such as amylase, protease, lipase

48

What does a sperm cell use enzymes for?

to digest a path through the jelly coat of the egg cell

49

Do plants contain enzymes?

yes – they control many reactions inside plant cells
anywhere a reaction takes place

50

Why are proteins and carbohydrates examples of polymers?

They are made up of many similar molecules/monomers.

51

Which monomers make up starch?

Glucose

52

Which monomers make up a protein?

amino acids

53

Are enzymes carbohydrates, proteins or lipids?

proteins

54

Which group of substances are fats and oils examples of?

lipids

55

Name one food that contains a lot of starch.

any suitable example such as: potato, pasta, bread, rice

56

What effect does the enzyme amylase have on starch?

breaks it down to small sugars/maltose

57

Food provides nutrients for growth. What else is it a source of, which we need for activity?

energy

58

Which cell structures break down molecules from food to release energy?

mitochondria

59

What are the subunits (small molecules) that make up carbohydrates?

simple sugars, e.g. glucose

60

Which two kinds of subunits form lipids (fats and oils)?

fatty acids and glycerol

61

Which kind of large biological molecule are enzymes?

Proteins

62

Which subunits make up enzymes?

Amino acids

63

Amylase is a kind of enzyme. Where is it found in humans?

mouth/salivary glands and small intestine/pancreas

64

What is a catalyst?

A molecule that speeds up the rate of a reaction

65

Why are enzymes called biological catalysts?

They are molecules found inside living organisms that speed up the rate of reactions.

66

What is a substrate?

A molecule that is changed in a reaction

67

What is the substrate for amylase?

starch

68

Starch synthase is an enzyme that catalyses the synthesis of starch. Explain what this means.

The enzyme combines with subunits/small sugar molecules and helps them join together to form starch.

69

What are the subunits of enzymes?

amino acids

70

Why do different enzymes have different 3D shapes?

The amino acids are arranged in a different order in different proteins.

71

Which kind of large organic molecule does a protease digest?

proteins

72

Which kind of enzyme would break down a food stain made by sunflower oil?

lipase

73

What is the name of the part of an enzyme into which the substrate fits?

active site

74

Why do most enzymes only work with one substrate?

Only substrates with the same shape as the active site can sit in the site and take part in the reaction.

75

Enzymes are specific to their substrate. What does this mean?

The enzyme will only work with particular substrates – those substrates that have the right shape.

76

Which term describes an enzyme in which the active site has permanently changed shape?

denatured

77

What effect does a large change of shape of an enzyme's active site have on how the enzyme works?

The enzyme no longer works.

78

Give two examples of changes in the cell environment that could cause the active site to change shape.

pH, temperature

79

Which cell structure surrounds every kind of cell?

cell surface membrane

80

What is the function of this cell structure?

to control what enters and leaves the cell

81

Name one gas that a cell needs to take in from its surroundings, and explain your answer.

oxygen needed for respiration/to release energy in mitochondria; carbon dioxide needed for photosynthesis

82

Name one other substance that a cell needs to take in from its surroundings, and explain your answer.

any suitable answer, such as glucose/sugar needed for respiration

83

Carbon dioxide is produced inside a cell and moves out of the cell by diffusion. What does this mean?

there is an overall movement of gas particles from where there are more of them to where there are fewer

84

Name one other substance that is made inside a cell and leaves the cell.

any suitable substance, such as enzymes or hormones that are secreted

85

Name two substances that plants take in from the soil through their roots.

water and dissolved mineral salts

86

There is a 5% sucrose solution and a 10% sucrose solution. Which solution has the higher concentration of sucrose?

10% solution

87

Two beakers contain the same volume of solution. One is a 10% sodium chloride solution, the other is a 5% sodium chloride solution. Which beaker contains more water molecules?

5% solution