Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology A Level > Cells > Flashcards

Cells Flashcards

1
Q

What is the primary difference between prokaryotic cells and eukaryotic cells?

A

Eukaryotes are complex (all animal and plant cells), prokaryotes are smaller and simpler (bacteria).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What organelles do plant cells have that animal cells don’t?

A

Cell wall, vacuole and chloroplasts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How do algal and fungal cells differ from plant cells?

A

Agal cells the same, fungal cells don’t have chloroplasts and their cell wall is made of chitin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cell membrane.

A

Regulates movement of substance in and out of the cell, also has receptor molecules which respond to chemicals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Nucleus.

A

Contains genetic information and controls the cells activities.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Mitochondria.

A

Site of aerobic respiration where ATP is produced.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Chloroplast.

A

Where photosynthesis occurs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Golgi apparatus.

A

Processes and packages lipids and proteins, also makes lysosomes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Golgi vesicle.

A

Stores lipids and proteins made by apparatus and transports them out of the cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Lysosome.

A

Breaks down invading cells or dead organelles - contains digestive enzymes lysozymes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Ribosomes.

A

Produces proteins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Rough endoplasmic reticulum

A

Folds and process proteins from ribosomes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Smooth endoplasmic reticulum.

A

Synthesises and processes lipids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Cell wall.

A

Supports cells keeping them rigid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Vacuole.

A

Keeps cell rigid and turgid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a tissue?

A

Group of cells working together to perform a particular function.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What makes organs and organ systems?

A

Different tissues working together form organs and different organs make up an organ system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What similarities do prokaryotic and eukaryotic cells have?

A

Plasma membrane, cell wall (made of murein), cytoplasm, ribosomes (smaller in pro).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What differences do prokaryotic and eukaryotic cells have?

A

Capsule, plasmids, free circular DNA in coiled up strand, flagellum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Capsule.

A

Made up of secreted slime, helps protect bacteria from immune system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Plasmids.

A

Small loops of DNA that contain genes for antibiotic resistance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Flagellum.

A

Long structure that rotates allowing the cell to move.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What if the difference in cytoplasms?

A

Prokaryotic cells have no membrane bound organelles.

24
Q

What do viruses do?

A

Invade host cells and reproduce inside other organisms.

25
Q

Structure of a virus.

A

Core of genetic material, capsid (protein coat around core) and an attachment protein (allows it to attach to host cells).

26
Q

How do prokaryotic cells replicate?

A

Binary fission.

27
Q

Describe binary fission.

A
  1. Circular DNA and plasmids replicate
  2. Cell gets bigger and DNA moves to opposite poles
  3. Cytoplasm begins to divide and new cell walls begin to form
  4. Cytoplasm divides and two daughter cells are produced
28
Q

Describe how viruses replicate.

A

Attachment proteins bind to complementary receptor proteins on host cells where they inject their DNA or RNA into the host cell. It then uses the cells machinery to replicate.

29
Q

Define magnification.

A

How much bigger the image is than the specimen:

mag=image/real object

30
Q

Define resolution.

A

How well microscope distinguishes between two points that are close together.

31
Q

List the features of a light microscope.

A

Use light to form an image, lower resolution (0.2), lower magnification (x1500).

32
Q

List features of electron microscopes.

A

Use electrons to form images, have higher resolution (0.0002) so give more detail (can be used to look at organelles), higher magnification (x 1,500,000).

33
Q

What is magnification measured in?

A

Micrometers (um).

34
Q

Describe features of a transmission electron microscope.

A

Use electrons to focus a beam of electrons through the specimen, denser parts absorb more electrons making them look darker.

35
Q

Why are TEMs good and why are they bad?

A

High resolution allowing you to see inside organelles, but they can only be used for thin specimens.

36
Q

Describe the features of scanning electron microscopes.

A

Scan a beam of electrons across the specimen which bounce off and gather in a cathode ray tube, forming an image.

37
Q

Why are SEMs good and why are they bad?

A

They show the surface of the specimen and an create an 3D image using thick specimen, but they give lower resolution than TEMs.

38
Q

How would you prepare a temporary mount on a slide?

A

Small drop of water onto slide and add a thin section of the specimen on top, add a stain to highlight the objects in the cell, add cover slip careful long lowering it down to prevent air bubbles.

39
Q

What is homogenisation? (cell fractionation step 1)

A

Vibrating or grinding breaks up plasma membrane releasing the organelles. Must be kept ice cold to keep enzymes from breaking down organelles and isotonic to prevent osmosis damaging organelles, buffer solution used also.

40
Q

How is filtration done in cell fractionation? (step 2)

A

Homogenised cells solution filtered through a gauze, separating any large cell or tissue debris. Organelles are small a bough to pass through.

41
Q

Describe ultracentrifugation (step 3 cell fractionation).

A
  1. Cell fragments centrifuged at low speed, heaviest organelles (nuclei) form a pellet and the rest remain in the supernatant.
  2. Supernatant drained and re-centrifuged at a higher speed, next heaviest organelles (mitochondria) form a pellet.
  3. Supernatant drained and centrifuged even faster, process repeated until the pellet is made up of lighter and lighter organelles.
42
Q

Why is mitosis needed?

A

Growth of organisms and repair of damaged tissue.

43
Q

Name the stages of the cell cycle.

A

Mitosis, gap phase 1 (G1), synthesis (S) and gap phase 2 (G2).

44
Q

What happens in G1?

A

Cell grows and new organelles and proteins are made.

45
Q

What happens in S stage?

A

Cell replicates its DNA ready for mitosis.

46
Q

What happens in G2?

A

Cells keep growing and proteins needed for cell division are made.

47
Q

What is the order of the stages in mitosis?

A

Interphase, prophase, metaphase, anaphase, telophase.

48
Q

What is the centromere?

A

What joins the two chromatids together.

49
Q

What happens during interphase?

A

Cell prepares to divide, DNA unravelled and replicated, the organelles replicate also and ATP content increased.

50
Q

What happens during prophase?

A

Chromosomes condense (shorter and fatter), centrioles move to opposite poles and spindle fibres begin to reform, nuclear envelope breaks down and chromosomes are free in the cytoplasm.

51
Q

What happens during metaphase?

A

Chromosomes line up along the centre of the cell and spindle attaches to their centromere.

52
Q

What happens during anaphase?

A

Centromeres divide separating sister chromatids, spindle contracts pulling chromatids to opposite poles.

53
Q

What happens during telophase?

A

Chromatids lie at opposite pole and uncoil, nuclear envelope forms around each group of chromosomes, cytoplasm divides (cytokinesis) and two genetically identical daughter cells are produced.

54
Q

What causes cancer?

A

Uncontrolled cell division when a gene is mutated.

55
Q

What is the issue with cell cycle disrupting craver treatments?

A

Treatments don’t distinguish between normal body cells and kill them also.

56
Q

How does disrupting G1 act as a cancer treatment?

A

Chemotherapy prevents synthesis of enzymes needed for DNA replication - preventing S phase.

57
Q

How can disrupting S phase act as cancer treatment?

A

Radiation and some drugs damage DNA, during cell cycle DNA is check for damage, if body detects damage the cell kills itself.

Biology A Level (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions