Cell Biology Flashcards

1
Q

Give two examples of a Erukaryotic cell

A
  • animal cell

- plant cell

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2
Q

What is a difference between a prokaryotic and eucaryotic cell?

A

-a eukariyotic cell has a nucleus

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3
Q

What does a nucleus contain

A

DNA

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4
Q

Define a Eukaryotic cell

A

a cell that contains genetic material (DNA) in an enclosed nucleus

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5
Q

What are the 3 main features of the Eukaroyotic cell?

A
  • cell membrane (NOT cell wall)
  • cytoplasm
  • nucleus
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6
Q

Name an example of a prokaroyotic cell

A

-bacteria cell

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7
Q

What are the features of a prokaroyotic cell

A
  • the genetic material is not enclosed in a nucleus

- the cells are much smaller

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8
Q

How does the prokaroyotic cell contain its DNA

A
  • within a single loop

- or maybe a small ring of DNA

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9
Q

What are the structrail features of a prokaryotic cell?

A
  • Cell membrane
  • bacterial cell wall
  • no nucleus
  • loops of DNA and plasmids
  • cyctoplasm
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10
Q

how big is a typical human cell?

A

10-20 micro meters

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11
Q

What is magnitude?

A

A way of saying if something is greater or smaller

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12
Q

What is one order of magnitude?

A

10x

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13
Q

What is the Cytoplasm

A

a watery solution, where chemical reactions take place

-for example the first stage of respiration

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14
Q

What is the cell membrane

A

controls molecules that can enter and leave the cell

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15
Q

What is the mitochondria

A

where aerobic respiration takes place inside the cell

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16
Q

What are Ribohsomes

A

They are the sites of protein synthesis

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17
Q

what are the structuial features of the plant cells

A
  • they have a regualr shape
  • vacuole
  • nuclues
  • cytoplasm
  • cell membrane
  • mitochondria
  • ribhosomes
  • choloroplasts
  • cell wall
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18
Q

What are chloroplasts?

A
  • found in plant cells
  • contain cholorplasts
  • site of photosynthesis
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19
Q

What is the cell wall?

A
  • found in plant cells
  • made from cellulose
  • strengthens the cell wall
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20
Q

what is a vacuole?

A
  • found in plant cells
  • filled with a fluid called cell sap
  • helps plant keep its shape
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21
Q

Give three examples of animal cells that are specilised

A
  • sperm cell
  • nerve cell
  • muscle cells
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22
Q

What is differensiation

A

when cells have become specilised

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23
Q

How are sperm cells specialised

A
  • only conatin half of the chromosones
  • long tail - can swim
  • streamline
  • has mitrocondria - creates energy
  • enzymes - can digest there way through the ovum
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24
Q

How is a nerve cell specilised

A
  • has a long axon
  • wrapped in Myelin - speeds up transmission
  • end has synapses - allow charge to flow from one to another
  • has dendrites - can cnnect to other cells easily
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25
Q

How are muscle specialised?

A
  • can contract (get smaller)
  • protein fibres that can change there length
  • packed full of mitochondria - can create energy
  • they work together to form a tissue
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26
Q

Give 3 examples of specialised plant cells

A
  • root hair cells
  • xylem cells
  • phloem tubes
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27
Q

How are root hair cells specialised?

A
  • increase surface area - absorb water and dissolve minerals

- Do not contain chloroplast - can’t get light

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28
Q

How are xylem cells specilised

A
  • Have very thick walls with lignin (lignin kills the cells)
  • The end walls between the cells have broken down - flow easily
  • has no nucleus, cytoplasm, ribhosomes or vacuole - this makes it easier for water and minerals to flow
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29
Q

How are pholem cells specilised

A
  • it has phloem vessel cells - little cytoplasm - this means that they have a companion cells with everything they need
  • this provides energy as it has mitochondria
30
Q

What do microscopes do?

A

magnify an image

31
Q

What are some probelms with a light microscope?

A
  • they have limited microfication

- they have limited resolution

32
Q

what are the advantages of the electron microscopes

A

-they have a much greater magnification and resolution

33
Q

What is binary fission

A

-when one bacterial cell splits into to cells (binary fission)

34
Q

what conditions need to be correct for binary fission to happen?

A
  • enough time

- tempreture is suitable

35
Q

What is the equation to find the number of bacteria

A

number of bacteria = 2^n

36
Q

What are the two ways to grow bacteria?

A
  • agar gel plate

- nutrient broth solution

37
Q

How do we make sure that when culturing micro organisms, we do not contanimate anything?

A
  • first sterilise everything - kills anything unwanted
  • move bacteria with innoculating loop - pass through flame
  • attach lid with adhisive tap
  • place upside down in incubator - stops mositure dripping onto the bacteria
38
Q

What tempreture are mico organisms incubated at in school?

A

25 degrees - reduces chance of harmful bacteria

39
Q

What are chromosones?

A

-Strips of DNA that carry genes

40
Q

What is the cell cycle

A

this is cells dividing to increase the amount

41
Q

What is the process of mitosis?

A

satge 1: DNA replicates to form two copies of each chromosome - this is done in the neucleus and both copies are attached. Internal cell organs, like mitochondria and ribhosomes also duplicate as the cell widens
Stage 2:Mitosis takes place - one set of chromosomes is pulled to each end of the cell and the neucleus also divides
Satge 3: The cytoplasm and the cell membrane divides to form two identical cells

42
Q

What are the functions of mitosis

A
  • essential for growth and development for multicellular organisms (plants and animals)
  • mitosis takes place when an organism repaids
  • mitosis takes place during asexual reproduction
43
Q

Describe what happens when a sperm cell joins with an ovum

A

When fertilisation takes place, the fertilised ovum forms a ball via mitosis. This is called an embryo. Over time, these cells continue mitosis and change to form specilised cells, like nerve or muscle cells. This process is called differentiation. Over time, this forms the human body.

44
Q

Can any cell differentiate to become specialised when there is an embryo?

A

Yes, when there is an embryo, any cell can change and differentiate to become a specilised cell.

45
Q

What is an Embyonic Stem cell?

A

a cell when there is an embryo that can become a differentiated cell

46
Q

What is a stem cell?

A

an undifferentiated cell which can give tise to more cells of the same type and can differentiate to form other cells

47
Q

Where else can you find stem cells?

A

-bone marrow - however they can only differentiate to form blood cells.

48
Q

Can stem cells in an adult embyo be used to create anything?

A

No, they are limited to what they can differentiate to.

49
Q

What can stem cells be used for?

A
  • growing new organs
  • replacing bone marrow
  • therapeutic cloning
50
Q

How are the stem cells from bone marrow used to treat Lukaemia patients?

A
  • the existing bone marrow is destroyed
  • the patient recieves a transplant of bone marrow form a donor
  • stem cells in the bone marrow now divide and make new bone marrow. They can also differentiate to form blood cells.
51
Q

What are problems with bone marrow transplants?

A
  • donor has to be compatiable - otherwise white blood cells produced will attack the patient
  • there is a risk that viruses can be passed from the donor to the patient
52
Q

What is theraputic cloning?

A
  • when an embryo is produced with the same genes as a patient
  • stem cells from the embryo can be transplanted into the patient without being rejected
  • the stem cells can then differentiate to replace cells that need to be replaced
53
Q

Why is theraputic cloning important?

A

-it can be used against diabetes or paralysis

54
Q

What are disadvantages of theraputic cloning?

A
  • ehtical or religious objections

- expensive

55
Q

Where are stem cells in plants located?

A

-roots and buds. The stem cells are called Meristem Tissue

56
Q

What can meristem tissues be used for?

A
  • cloneing a rare plant to stop it going extinct

- cloning crops for farmers

57
Q

What is diffusion?

A
  • a way that molecules move in and out of the cell membrane

- Spreading out particles resulting in a net movement from and area of high cnocentration to a low concentration.

58
Q

How do oxygen molecules, carbon dioxide molecules and urea move when there is a cell membrane

A
  • oxygen molecules move inwards - to a lower concentration
  • carbon dioxide molecules move outwards - to a lower concentration
  • Urea (a waste product produced inside cells) moves outwards and gets excreted by the kidneys
59
Q

What are the factors that effect diffusion

A
  • The greater the concentration gradient, the faster diffusion takes place
  • The higher the tempreture, the greater the rate of diffusion, this is as the particles have higher kinetic energy
  • The greater the surface area of the membrane, the faster the diffusion
60
Q

What happens to the surafce area : volume ratio as orgnisms increase size? What problem does this create for multicellular organisms?

A
  • the ratio falls sharply

- Multicelular organisms do not have a large enough surface area for there volume

61
Q

How do fish counteract a small volume to surface area ratio?

A

-fish have gills. Water basses through the gills and the oxygen from the water diffuses into the blood and it returns to the body

62
Q

How do gills help?

A
  • They have a large surface area
  • They have a thin membrane - short diffusion path
  • efficiant blood supply - take oxygenated blood away
63
Q

How do gills help?

A
  • They have a large surface area
  • They have a thin membrane - short diffusion path
  • efficiant blood supply - take oxygenated blood away
64
Q

What is osmosis?

A

-the diffusion of water from a dilute solution to a concentrated solution - through a partially permeable membrane

65
Q

What do partially permeable membranes do

A

allow some molecules to pass through, but not all

66
Q

Where would water diffuse to from a high concentration of water particles. a higher concentration of water particles or a lower concentration of water particles

A

-a low concentration of water particles as they follow the rules of osmosis

67
Q

What happens if an animal cell is plased into water?

What happens if it is taken out of the water

A
  • the water will be drawn into the animals cell and i could possibly burst
  • this is as there is a low concentration of water in the cytoplasm
  • the cell will then shrink
68
Q

What happens if a plant cell is plased into water?

What happens if it is taken out of the water

A
  • The water will be drawn into the plant cell however it can’t burst as the cell wall keeps the shape of the cell - the cell becomes turgid
  • If it is taken out, it will shrink and become flacid
69
Q

What is Active Transport

A

This moves substances from a more dilute solution to a more concentrated solution - against the concentration gradient. Active Transport requires energy from respiration

70
Q

How is Active Transport different from diffusion

A
  • move against concentration gradient

- does require energy from respiration - this means the cells have mitocondria

71
Q

What are two examples of active transport?

A
  • Lumen of small intestine - sugar needs to go into cell, however, there is a larger concentration in the cell. Instead, active transport pulls them in towards the cell where they are transported into the blood
  • Root hair cells in plants - ions, such as magnesium, come into the root via active transport as there is a lower concentration outside the root