Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BIOLOGY > Cells > Flashcards

Cells Flashcards

1
Q

Maginification

A

How much bigger an image is from a microscope compared to the specimen.

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

Resolution.

A

The quality of the image.

Eg) how well you can distinguish between two points that are close together.

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

S.E.M

A

Scanning electron microscope

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

T.E.M

A

Transmission electron microscope.

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

Ultrastructure

A

The minute structure if a biological specimen ( anything inside a cell)

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

Wavelength

A

The distance between two successive crests of a wave.

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

The equation for magnification

A

Length of an Image / length of an object.

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

Cell fractionation

A

The process where cells are broken up and the different organelles they contain are separated.

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

What are the three steps of cell fractionation?

A
  • Homogenisation = breaking up of cells
  • filtration = getting rid of large pieces of debris.
  • ultracentrifugation= separating the organelles.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does ultracentrifugation work?

A

Cell fragments poured into the centrifuge.

Spins at low speed; heavy organelles sent to bottom. (Pellets) and are filtered out.

The less dense supernatant is then put back in the centrifuge.

Continue until the desired organelle is the pellet.

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

Electron

A

Negatively charged particle

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

Photomicrograph

A

Image of a microscopic object. Taken with aid of a microscope.

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

How does an electron microscope work?

A

Beams of electrons fired through sample. And lenses.

Shadow image of specimen created.

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

Difference between TEM and SEM

A

TEM = higher resolution
= must use v. Thin,

SEM = use on thicker specimen and can be 3D.
= lower resolution;

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

Pros and cons of SEMs

A

Pros = use on thicker specimen and can be 3D.

Cons = lower resolution than TEM. & must be dead specimen.

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

Pros and cons of TEM

A

Pros = higher resolution

Cons = must use v. Thin, dead specimen

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

Eye piece graticule

A

Glass disk in the eyepiece with 1cm scale on it.

=measure size of object. But first must calibrate.

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

Calibrate

A

Find the correct magnification by comparing the reading of the graticule to a standard measurement (stage micrometer)

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

Stage micrometer

A

Microscope slide with a 2mm long scale unit.

0.01 subdivisions.

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

Steps to calibrating a graticule.

A
  1. Line up graticule to micrometer.
  2. See how many units on the graticule scale = 10(e.g) on the micrometer.
  3. Divide each side to show what 1unit on micrometer = on graticule scale.

= 40x magnification.

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

How can you measure cell size using a graticule?

A

Find size of image (eg. 7mm = 7000micrometers)

Divide image size by magnification.
Eg. 7000/40x = 175micro m

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

Ultrastructure

A

The internal structure of a cell which suits its function.

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

Eukaryotic cells

A

Type of cell with specific structure for specific functions.

Have distinct nucleus.
Posses membrane bound organelles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Nucleus

A

Holds DNA

Control centre of cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Nuclear envelope
Double membrane surrounding the nucleus
26
Mitochonria
Site of ATP synthesis (energy carrier molecule) Site or aerobic stages of respiration.
27
Ribosome
Expresses the genetic code from nucleic acid into protein. | Process called translation.
28
Flagellum
Tail like structure. Allows for movement.
29
Lysosome
Contain digestive enzymes
30
Rough endoplasmic reticulum.
Site of protein synthesis. Studded with ribosomes.
31
Smooth endoplasmic reticulum.
Synthesis, transport and store of lipids and carbohydrates.
32
Golgi complex (apparatus)
Packages macromolecules (eg. Lipids and proteins) after synthesis. Before destination.
33
Chloroplast
Organelle in plant cells involved in carrying out photosynthesis.
34
Cell wall (plants)
Wall of cellulose used to control what enters and leaves a cell.
35
Cell wall if algae made of?
Cellulose and/or | Glycoproteins
36
Whats is the cell wall of fungi made of?
* Chitin (Nitrogen containing polysaccharide), * Glycan (polysaccharide) * glycoprotein
37
Valcule
Fluid filled sacs with single membrane Temporary food store, keeps turgid, holds pigment =attracts pollinating insects
38
Specialisation
When cells switch genes on and off to perform more specific functions. = they can be more efficient
39
Tissue Eg. Human and plant
Group of similar cells arranged together to suit a specific function. Epithelial tissue. Xylem.
40
Organs Eg. Human and plant
Tissues aggregated together. They coordinate to perform 1 particular function. Through a variety of other functions. Lungs Leaf
41
Organ system Give eg.
Group of organs working together for better efficiency in performing certain functions. Eg. Digestive system
42
Adv. of differentiation
++ efficiency Can have specific organelles and structures to suit their function.
43
Prokaryotic cells
Cells which have no true nucleus. No nuclear membrane/ envelope. Smaller than eukaryotic cells.
44
Ultrastructure of prokaryotic cells
Cell wall Capsule Plasma membrane Ribosomes 70s(
45
Similarities between prokaryotic and eukaryotic cells.
Both have phospholipid plasma membranes Both have ribosomes (p=R70s E=R80s)
46
Differences between prokaryotic cells and eukaryotic cells.
Size: E>P Organisation: P= single celled E= part of tissue DNA: P=circular strand and plasmid E= chromosomes Mitochondria: absent/present Nucleus: absent/ present Cell wall: present/only in plants
47
Capsule
Mucilaginous layer of slime around cell wall. = protection and sticks cells together
48
Plasmid
Circular piece of DNA (small) caries genetic info Allows independent reproduction in host cells Gives resistance cell
49
Virus
Prokaryotic cell Replicates in host cells Smaller than bacteria
50
Caspid
Protein coat enclosing nucleic acid in prokaryotic cells(viruses)
51
Horizontal gene transitione
Process by which viruses inject their DNA into host cells and cause the cell to make the virus cells
52
What is mitosis?
The formation of two identical daughter cells due to cell division For cell growth,repair/replacement and asexual reproduction.
53
Interphase
Period proceding mitosis. | Where Cellular content and DNA replicates and cells grow, preparing for mitosis.
54
Prophase
* chromosomes shorten and thicken = becomes visible * centrosomes form spindle fibres and move to the poles * nuclear envelope breaks down
55
Chromosome
Threadlike structures located in the nucleus. Made up of protein and a single molecule of DNA.
56
Chromatid
Each of the two strands that make up a chromosome when it divides during cell division. 2 chromatids =1 chromosome joined together with a centromere
57
Metaphase
* Centrosomes form spindles by producing microtubules which connect to the centromere of the chromosome. * chromosomes are moved to the spindle equator. •Chromosomes align along equator. (Still attached to the spindle fibres)
58
Anaphase
* centromeres split and pull the chromatids apart. * chromosomes move to opposite poles •spindle poles move further apart ready for division. = 46chromosomes & 92 chromatids >>> 92 chromosomes & 92 chromatids (with 1 centromere each)
59
Telophase
The chromosomes cluster at opposite poles Chromosomes become dispersed (released by the spindle fibres) Nuclear envelope begins to reassembles.
60
Cytokinesis
Cell separates into two daughter cells with 46 chromosomes and 46 chromatids.
61
What are the three stages of the cell cycle?
Interphase Nuclear division Cytokinesis
62
Interphase
No division takes place Rest phase 90% of the process G1,S and G2 occur
63
What are the three phases within interphase?
Growth 1 Synthesis Growth 2
64
In interphase: What happens during the initial growth phase?
May be cell specialisation & increase in number of organelles.
65
In interphase: What happens during the S phase?
Synthesis of new DNA. DNA replication and chromosome duplication >> 2 chromatids
66
In interphase: What happens during the second growth phase?
Increase in number of organelles increases. Cell growth Preparation for cell division

BIOLOGY (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions