Topic 1 - Key Concepts in Biology Flashcards

1
Q

Eukaryotes

A

Organisms that are made up of eukaryotic cells

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2
Q

Prokaryotes

A

A prokaryotic cell (single-celled organism)

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3
Q

Nucleus

A

Contains genetic material that controls that activities of the cell

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4
Q

How is genetic material arranged?

A

Into chromosomes

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5
Q

Cytoplasm

A

A gel-like substance where most of the chemical reactions happen

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6
Q

What does cytoplasm contain?

A

Enzymes that control the chemical reactions

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7
Q

Cell membrane

A

Holds the cell together and controls what goes in and out

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8
Q

Mitochondria

A

Where the most of the reactions for respiration take place

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9
Q

What does respiration transfer?

A

Energy that a cell needs to work

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10
Q

Ribosomes

A

Involved in translation of genetic material in the synthesis of proteins

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11
Q

Cell wall

A

Supports the cell and strengthens it

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12
Q

What is the cell wall made of?

A

Cellulose

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13
Q

Large vacuole

A

Maintains the internal pressure to support the cell

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14
Q

What does the large vacuole contain?

A

Cell sap, a weak solution of sugar and salts

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15
Q

Chloroplasts

A

Where photosyntehsis occurs, which mades food for the plant

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16
Q

What green substance do chloroplasts contain?

A

Chlorophyll

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17
Q

Are bacterial cells smaller or larger than plant/animal cells?

A

A lot smaller

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18
Q

Chromosomal DNA

A

Controls the cell’s activities and replication

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19
Q

Where does the chromosomal DNA float?

A

Freely in the cytoplasm

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20
Q

Plasmid DNA

A

Small loops of extra DNA that aren’t part of the chromosome

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21
Q

What does plasmid DNA contain?

A

Genes for things like drug resistance

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22
Q

Does plasmid DNA pass between bacteria?

A

Yes

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23
Q

Flagellum

A

A long, hair-like structure that rotates to make the bacerium move

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24
Q

What can flagella be used to move bacteria away from?

A

Harmful substances like toxins

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25
Q

What can flagella be used to move bacteria towards?

A

Benefitial things like nutrients or oxygen

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26
Q

What is a specialised cell?

A

Cells that have a structure which makes them adapted to their function

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27
Q

Steps of fertilisation

A
  1. Nucleus of egg cell fuses with nucleus of sperm cell
  2. Fertilised egg is created
  3. Develops into an embryo
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28
Q

How many chromosomes are in an egg cell and a sperm cell?

A

23

29
Q

True/False: egg cells and sperm cells are haploid

A

True

30
Q

How many chromosomes does the resulting cell have after fertilisation?

A

46

31
Q

Main functions of an egg cell

A

To carry the female DNA and nourisht he developing embryo in early stages

32
Q

Adaptaions of an egg cell

A
  1. Contains nutrients in the cytoplasm to feed the embryo
  2. Has a haploid nucleus
  3. Straight after frtilisation, its membrane changes structure to stop any more sperm getting in
33
Q

What does the membrane changing structure after fertilisation make sure of?

A

The offspring end up with the right amount of DNA

34
Q

Main function of a sperm cell

A

To transport the male’s DNA to the female’s egg

35
Q

Adaptations of a sperm cell

A
  1. Has a long tail so it can swim to the egg
  2. Has lots of mitochondria in the middle section to provide the energy (from respiration) needed to swim this distance
  3. Has an acrosome at the front of the head
  4. Contains a haploid nucleus
36
Q

What does the acrosome store in a sperm cell?

A

Enzymes needed to digest its way through the membrane of the egg cell

37
Q

What are cilia?

A

Hair-like structures on the top surface of the cell

38
Q

Function of ciliated epithelial cells

A

Move substances

39
Q

What do the cilia do?

A

Beat to move substances in one direction, along the surface of the tissue

40
Q

When were light microscopes invented?

A

1590s

41
Q

How do light microscopes work?

A

By passing light through the specimen

42
Q

What do light microscopes let us see?

A

Things like nuclei and chloroplasts

43
Q

What can we use light microscopes to study?

A

Living cells

44
Q

When were electron microscopes invented?

A

1930s

45
Q

What do electron microscopes use instead of light?

A

Electrons

46
Q

Electron microscopes have a higher … and … than light microscopes

A

Magnification and resolution

47
Q

What is the difference between electron microscopes and light microscopes?

A

Electron microscopes let us see much smaller things in more detail (like the internal structure of mitochondria and chloroplasts)

48
Q

What have electron microscopes allowed us to have a much greater understanding of?

A

How cells work and the role of sub-cellular structures

49
Q

What is magnification?

A

How many times bigger the image is

50
Q

What is the formula for magnification using lens magnification?

A

total magnification = eyepiece lens magnification x objective lens magnification

51
Q

What is the formula for magnification using measurements of the image and specimen?

A

magnification = image size / real size

52
Q

What is 0.000005 m in standard form?

A

5 x 10^-6 m

53
Q

How do you convert picometres to nanometres?

A

Divide by 1000

54
Q

How do you convert millimetres to micrometres?

A

Multiply by 1000

55
Q

What is the order of units for magnification (smallest to largest)?

A

Millimetre, micrometre, nanometre, picometre

56
Q

What are enzymes?

A

Enzymes are biological catalysts produced by living things

57
Q

What is a cataylst?

A

A substance which increased the speed of a reaction, without being changed or used up in the reaction

58
Q

What do enzymes reduce the need for?

A

High temperatures

59
Q

Why do we have enzymes?

A

To speed up the useful chemical reactions in the body

60
Q

What is the molecule changed in the enzyme reaction?

A

The substrate

61
Q

What is an active site?

A

The part of the enzyme where substrate molecules bind and a chemical reaction take place

62
Q

Why do enzymes only work with one substrate?

A

They have a high specificity because, for the enzyme to work, the substrate has to fit into the active site

63
Q

What happens when the substrate’s shape doesn’t match the active site’s shape?

A

The reaction won’t be catalysed

64
Q

Why is it called the ‘lock and key’ mechanism?

A

The substrate fits into the enzyme’s active site just like a key fits into a lock

65
Q

What is a substrate?

A

The molecules on which enzymes act

66
Q

How does temperature affect the rate of reaction?

A

A temperature that is too hot will break some of the bonds holding the enzyme together. This changes the shape of the enzyme’s active site, so the substrate won’t fit anymore. The enzyme is denatured.

67
Q

What is the optimum temperature (for an enzyme)?

A

The temperature that the enzyme works best at

68
Q
A