Brainscape's Knowledge GenomeTM

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


See full index

IB Biology > 1.2 - Ultrastructure Of Cells > Flashcards

1.2 - Ultrastructure Of Cells Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

History of electron microscopes/benefits/compared to light microscopes

A

Developed in Germany in the 1930’s
Allows images to be produced of things 200 times smaller than with light microscopes
Able to see the structure of eukaryotic cells - more intricate than expected

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

What electron microscopes revealed

A

The ultrastructure of cells

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

Size that the human eye can see unaided

A

0.1 mm

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

Size that the light microscope allows us to see

A

200 nano meters

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

Define resolution

A

Making the separate parts of an object distinguishable by eye

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

Why electron microscopes have a higher resolution than light microscopes

A

Because electrons have a much shorter wavelength than the wavelength of light

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

Main difference between Prokaryotes and Eukaryotes

A

Presence of a nucleus (in Eukaryotes - membrane bound nucleus, Prokaryotes - no nucleus)

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

Describe the cell wall

A

Much thicker and stronger than the cell membrane. It protects the cell, maintains the cells shape, and prevents the cell from bursting

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

Cytoplasm in Prokaryotes

A

One uninterrupted chamber - compartments not separated by membranes

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

Organelles in Eukaryotes

A

Present in the cytoplasm, have distinct structures with specialized functions

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

Size of ribosomes in Prokaryotes

A

70s

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

Define nucleoid

A

Region of the cell containing the DNA of the cell, usually in the form of one circular DNA molecule - DNA is not associated with proteins.
Is nucleus-like, but not a nucleus

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

The only way that living organisms can produce new cells is -

A

the division of pre-existing cells

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

Define Binary Fission

A

Cell division in prokaryotic cells, used for asexual reproduction

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

Describe Binary Fission

A
  1. Single circular chromosome is replicated
  2. The 2 copies of the chromosome move to opposite ends of the cell
  3. Cytoplasm divides
    - -> Each of the daughter cells contain one copy of the chromosome so they are genetically identical
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Products of Binary Fission

A

2 genetically identical daughter cells

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

Labels on a diagram of a prokaryotic cell

A

Ribosomes, cell wall, plasma membrane, cytoplasm, nucleoid, pilli, flagellum

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

Cytoplasm of Eukaryotes

A

Is compartmentalized with double membranes

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

Define organelles

A

The compartments in the cytoplasm

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

Advantages of the compartmentalized structure of Eukaryotes

A

Enzymes and substrates for processes can be concentrated
Potentially damaging substances can be kept inside the membrane of an organelle (eg. digestive enzymes in lysosomes)
Conditions like pH can be maintained at an ideal level for a particular process - different levels for different processes
Organelles and their contents can be moved around within the cell

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

Labels on a diagram of a eukaryotic cell

A

Nucleus, rough endoplasmic reticulum, Golgi apparatus, lysosome, mitochondria, free ribosomes, chloroplasts, vacuoles, vesicles, microtubules and centrioles, cilia, flagella

22
Q

Describe Nucleus

A

Double membrane, with pores. Contains the chromosomes of DNA associated with histone proteins.

23
Q

Describe Rough Endoplasmic Reticulum

A

Consists of flattened membrane sacs called cisternae, ribosomes attached on the outside of the cisternae. Classified as 80s.

24
Q

Function of the Nucleus

A

Location of DNA replication and transcribing to form mRNA, which is exported via pores into the cytoplasm

25
Q

Function of the Rough Endoplasmic Reticulum

A

To synthesize protein for secretion from the cell.

26
Q

Describe Golgi Apparatus

A

Consists of flattened membrane sacs called cisternae. Cisternae are not as long as in the RER, are often curved, do not have ribosomes attached. There are many vesicles nearby.

27
Q

Function of the Golgi Apparatus

A

Processing proteins which have been brought in by vesicles from the RER

28
Q

Describe lysosome

A

Single membrane, spherical, contain high concentrations of protein - makes them densely staining in micrographs. Contain digestive enzymes.

29
Q

Function of lysosome

A

digestive enzymes can be used to break down ingested food in vesicles, or break down organelles in the cell, or break down the whole cell

30
Q

Describe mitochondria

A

double membrane, with inner structures called cristae, and fluid inside called matrix.

31
Q

Function of mitochondria

A

Produce ATP for the cell by aerobic cell respiration, digests fat if it is being used as an energy source for the cell

32
Q

Describe free ribosomes

A

Appear as dark granules in the cytoplasm, are not surrounded by a membrane

33
Q

Function of free ribosomes

A

Free ribosomes synthesise protein, releasing it to work in the cytoplasm (as enzymes or in other ways)

34
Q

Describe chloroplasts

A

Double membrane, stacks of flattened sacs called thylakoids, usually spherical or ovoid. Starch grains may be present inside if they have been photosynthesising rapidly.

35
Q

Function of chloroplasts

A

Produce glucose and a wide range of other organic compounds by photosynthesis.

36
Q

Describe vacuoles and vesicles

A

Organelles that consist of a single membrane with fluid inside.

Vesicles are very small vacuoles

37
Q

Function of vacuoles and vesicles

A

Animals - some absorb food from outside and digest it inside vacuoles

Unicellular organisms - use vacuoles to expel excess water

Vesicles - used to transport materials inside the cell

38
Q

Describe microtubules and centrioles

A

Microtubules - small cylindrical fibres in the cytoplasm of cells

Centrioles - in animal cells, two groups of nine triple microtubules

39
Q

Function of microtubules and centrioles

A

Microtubules - variety of roles : including moving chromosomes during cell division

Centrioles - form an anchor point for microtubules during cell division, and for microtubules inside the cilia and flagella

40
Q

Describe cilia and flagella

A

Whip-like structures projecting from the cell surface

Contain a ring of double microtubules plus two central ones

Flagella - larger than cilia, normally only one present (as in sperm)

Cilia - smaller than flagella, normally many are present

41
Q

Function of cilia and flagella

A

Both used for locomotion

Cilia - can also be used to create a current in the fluid next to the cell

42
Q

How do gland cells secrete substances?

A

Through their plasma membrane

43
Q

What are the 2 types of gland cells in the pancreas?

A

Endocrine

Exocrine

44
Q

What do the endocrine cells in the pancreas do?

A

Secrete hormones into the blood stream

45
Q

What do the exocrine gland cells in the pancreas do?

A

Secrete digestive enzymes into a duct that carries them to the small intestine where they digest foods

46
Q

What is the function of the organelles that are in exocrine gland cells in the pancreas?

A

Organelles which are needed to:

Synthesise proteins in large quantities
Process proteins to make them ready for secretion
Transport proteins to the plasma membrane
Release proteins through the plasma membrane

47
Q

What are the organelles which are present in exocrine gland cells in the pancreas?

A 
Plasma membrane
Golgi apparatus
Mitochondrion
Vesicles
Nucleus
Lysosomes
Rough ER
48
Q

In a leaf, which cell type carries out the most photosynthesis?

A

Palisade mesophyll

49
Q

What is the function of a leaf?

A

Photosynthesis - producing organic compounds from carbon dioxide and other simple inorganic compounds, using light energy.

50
Q

What is the shape of palisade mesophyll cells?

A

Roughly cylindrical

51
Q

What organelles are present in a palisade mesophyll cell?

A 
Cell wall
Plasma membrane
CHLOROPLASTS - carrying out the most photosynthesis, so LOTS of these
Mitochondrion
Vacuole
Nucleus

IB Biology (5 decks)

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