Brainscape's Knowledge GenomeTM

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


See full index

Biology exam practise > Cells > Flashcards

Cells Flashcards

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

4 marks

Describe the structure and function of the nucleus.

A

Structure
1. Nuclear envelope and pores/ Double membrane and pores
2. Chromosomes/ DNA with histones
3. Nucleolus
Function
4. Holds genetic material for polypeptides production
5. DNA replication occurs
6. Production of mRNA/tRNA
7. Production of rRNA/ribosomes

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

What does it mean if cells become flaccid or turgid

A
  • If cells become turgid cells show water is absorbed by osmosis
  • If cells become turgid cells show cells have a lower water potential
  • If cells are not flaccid/plasmolysis cells show water is not lost by osmosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

2 marks

Give two features of all prokaryotic cells that are not features of eukaryotic cells

A
  • No membrane-bound organelles
  • Circular DNA
  • Murein in cell wall
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

1 mark

Name the main polymer that forms the following cell walls.
Plant cell wall
Fungal cell wall

A

Cellulose (plants) and Chitin (fungi)

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

6 marks

Contrast how an optical microscope and a transmission electron microscope work
and contrast the limitations of their use when studying cells.

A
  1. TEM uses electrons and optical uses light
  2. TEM allows a greater resolution
  3. So with TEM smaller organelles can be observed e.g. ribosome
  4. TEM view only dead specimens and optical can view live specimens
  5. TEM requires thinner specimens
  6. TEM requires a more complex/ time consuming preperation
  7. TEM focuses using magnets and optical uses glass lenses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

5 marks

Compare and contrast the DNA in eukaryotic cells with the DNA in prokaryotic cells.

A

Comparisons
1. Nucleotide structure is identical
2. Nucleotides joined by phosphodiester bond
3. DNA in mitochondria and chloroplasts same structure to DNA in prokaryotes
Compare
4. Eukaryotic DNA is longer
5. Eukaryotic DNA contain introns, prokaryotic DNA does not
6. Eukaryotic DNA is linear, prokaryotic DNA is circular
7. Eukaryotic DNA is associated with histones proteins, prokaryotic DNA is not

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

Define pathogen

A

Microorganism that causes disease/ an immune response

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

5 marks

Describe difference between active and passive immunity

A
  1. Active involves memory cells, passive does not;
  2. Active involves production of antibody by plasma cells / memory cells;
  3. Passive involves antibody introduced into body from outside
  4. Active long term, because antibody produced in response to antigen
  5. Passive short term, because antibody (given) is broken down;
  6. Active (can) take time to develop, passive fast acting.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

5 marks

When a vaccine is given to a person, it leads to the production of antibodies against a disease-causing organism. Describe how

A
  1. Vaccine contains antigen from pathogen
  2. Macrophage presents antigen on its surface
  3. T cell with complementary receptor protein binds to antigen;
  4. T cell stimulates B cell
  5. (With) complementary antibody on its surface
  6. B cell secretes large amounts of antibody
  7. B cell divides to form clone all secreting / producing same antibody.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

3 marks

Desribe 3 functions of the golgi apparatus

A
  1. Modifies and packages proteins
  2. Modifies and packages lipids
  3. Makes lysosomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does passive immunity work

A

Passive involves antibody introduced into body from external source
Adding the antibody would cause agglutination and increase efficiency of phagocytosis

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

The human papilloma virus contains a double-stranded DNA genome.
Which components are found in a human papilloma virus? Choose one
* Capsid and attachment protein
* Capsid, attachment protein and reverse transcriptase
* Capsule and attachment protein
* Cell-surface membrane and attachment protein

A

Capsid and attachment protein

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

5 marks

Outline the similarities in, and the differences between, the structures of chloroplasts and mitochondria.

A

Similarities
1. Double membrane;
2. Both contain (circular) DNA;
3. Both contain ribosomes;
Differences
4. Thylakoids/lamellae/grana v cristae;
5. Stroma v matrix;
7. Starch grains v no starch grains;

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

2 marks

Suggest how Streptococcus bacteria with a thicker capsule are more likely to survive and so cause lung disease.

A

Phagocytes less likely to bind to murein in cell wall
This decreases pahgocytosis as theres more binary fission

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

3 marks

Explain why phospholipids can form a bilayer but triglycerides cannot.

A
  • Phospholipid both hyrdophillic and hydrophobic
  • Triglycerides only hydrophillic
  • Hydrophillic phosphate head attracted to water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

State one role of a helper T cell.

A

Stimulating cytotoxic T cells
Stimulating B cells
Stimulating phagocytes;

17
Q

2 marks

Explain why viruses are described as acellular and non-living.

A
  1. Accelular= not made up of cells
  2. Non living= no metabolic reactions/ need a host cell to replicate
18
Q

Give one reason why antibiotics are not effective against viruses.

A

doesnt have a cell wall

19
Q

The movement of substances across cell membranes is affected by membrane structure. Describe how.

A
  1. Phospholids only allows non-polar, lipid-soulube molecules diffuse across phospholipid bilayer
  2. Phospholipid bilayer prevent diffusion of water- solube, polar molecules across membrane
  3. Carrier proteins allow active transport
  4. Carrier proteins and channel proteins allow facilitated diffusion
  5. Cholestrol affects rigidty/ fluidity
20
Q

5 marks

Name and describe five ways substances can move across the cell-surface membrane into a cell.

A
  1. Simple diffusion of small/non-polar molecules down a concentration gradient
  2. Facilitated diffusion down a concentration gradient via protein carrier and channel
  3. Osmosis of water down a water potential gradient
  4. Active transport against a concentration gradient via protein carrier using ATP
  5. Co-transport of 2 different substances using a carrier protein
21
Q

2 marks

Suggest and explain 2 ways the cell-surface membranes of the cell lining the uterus may be adapted to allow rapid transport of nutrients

A
  1. Memrane folded so large SA
  2. Large number of protein channels/ carriers for FD
  3. Large number of carrier proteins for active transport
  4. Large number of protein channels/ carriers for co-transport
22
Q

3 marks

Sodium ions from salt (sodium chloride) are absorbed by cells lining the gut. Some of these cells have membranes with a carrier protein called NHE3. NHE3 actively transports one sodium ion into the cell in exchange for one proton (hydrogen ion) out of the cell. Use your knowledge of transport across cell membranes to suggest how NHE3 does this.

A
  1. Co-transport
  2. Uses hydrolysis of ATP
  3. Sodium ion and proton bind to protein
  4. Protein changes shape to move sodium ion and proton across the membrane
23
Q

2 marks

Bacteria are often used in industry as a source of enzymes. One reason is because bacteria divide rapidly, producing a large number of them in a short time.
Describe how bacteria divide.

A
  1. Binary fission
  2. Replication of circular DNA
  3. Division of cytoplasm to produce 2 daughter cells
  4. Each with a single copy of circular DNA
24
Q

3 marks

Describe how phagocytosis of a virus leads to presentation of its antigens

A
  1. Phagosome/ vesicle fuses with lysosome
  2. Virus destroyed by lysozymes/ hydrolytic enzymes
  3. Antigen from virus are displayed on the cell membrane
25
Q

3 marks

Describe how presentation of a virus antigen leads to the secretion of an antibody against this virus antigen

A
  1. T helper cell receptor binds to antigen on the antigen- presenting cell
  2. T helper cell stimulates a specific B cell
  3. B cell divides by mitosis
  4. Forms plasma cells that release antibodies
26
Q

3 marks

Describe viral replication

A
  1. Attachment proteins attach to receptors
  2. Viral nucleic acid enters cell
  3. Reverse transcriptase converts RNA to DNA
  4. Cell produces viral proteins
  5. Virus assembled and released from cell
27
Q

2 marks

The scientists broke open the cells to produce a suspension of cell contents.
Describe how the scientists would remove large organelles from this suspension of cell contents.

A
  1. Centrifuge at low speeds
  2. Large/dense organelles removed in first pellet
28
Q

Use your knowledge of membrane structure to explain the results in absorbance
* E – Ethanol, water and acid (greatest absorbance)
* F – Ethanol and water (2nd)
* G – Water (lowest absorbance)

A
  1. Higher absorbance indicates more anthocyanin
  2. More membrane permeability results in more anthocyanin release
  3. E and F greater than water because phospholipids dissolve in ethanol
  4. E greater than F because acid denatures membrane proteins
29
Q

Cyclin D undergoes DNA replication faster

Some tumour cells contain higher than normal concentrations of cyclin D.
Suggest why higher than normal concentrations of cyclin D could result in a tumour.

A
  1. Shortens interphase/ DNA replication starts faster
  2. Uncontrolled cell division
  3. Resulting in a mass of abnormal cells

Biology exam practise (31 decks)

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