Brainscape's Knowledge GenomeTM

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


See full index

biology > 2.1 to 2.9 Cell division and growth > Flashcards

2.1 to 2.9 Cell division and growth Flashcards

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

State the two types of cell

A

● A series of events that take place in a cell involving cell growth, DNA replication and cell division
● It is described as the lifecycle of a cell

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

State the three stages of the cell cycle

A

Stage 1 - interphase
Stage 2 - mitosis
Stage 3 - cytokinesis

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

What is interphase?

A

The longest stage of the cell cycle that involves cell growth, the synthesis of new organelles and DNA replication

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

What does DNA replication involve?

A

● Double helix ‘unzips’ exposing two strands
● DNA bases align next to complementary bases on the DNA strands
● Complementary base pairs join
● Two identical DNA molecules formed

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

What is a chromosome?

A

A linear DNA molecule tightly coiled around proteins

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

What happens to chromosomes during DNA replication?

A

The DNA in the ‘arm’ of each chromosome (chromatid) is replicated.

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

What is mitosis?

A

A form of cell division that produces two diploid ‘daughter’ cells, both genetically identical to the parent cell.

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

Why is mitosis important in organisms?

A

● Asexual reproduction
● Growth
●Repair of damaged cells
● Cell replacement

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

State the four stages of mitosis

A

●Prophase
●Metaphase
●Anaphase
●Telophase

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

Outline prophase

A

● DNA condenses, chromosomes become visible
● Nuclear membrane disappears

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

Outline metaphase

A

● Chromosomes line up along the cell equator

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

Outline anaphase

A

● Spindle fibres attach to each chromosome
● ‘Arms’ of each chromosome pulled to opposite poles
● Chromatids separated

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

Outline telophase

A

● Nucleus of the cell divides
● New membrane forms around each set of chromosomes

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

What does cytokinesis involve?

A

● Division of the cell membrane and cytoplasm
● Two genetically identical ‘daughter’ cells produced

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

A cell divides by mitosis once every 2 minutes. Calculate the number of identical cells present after 10 minutes.

A

10 ÷ 2 = 5
5 cell divisions have taken place
2^5 = 32 cells

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

What is cancer?

A

● Non-communicable disease
● Uncontrolled cell division (due to damaged DNA) results in the formation of a primary tumour
● Tumour cells break off and spread to other tissues forming secondary tumours

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

What are percentile charts?

A

● A chart used to monitor growth
● Measurements (e.g. fetal length or head circumference) can be compared to the expected values at a certain age

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

What does the 95th percentile mean?

A

95% of measurements will be below the value of the 95th percentile

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

What can doctors determine from percentile charts? (3)

A

● Slower growth than normal (below the bottom line)
● Faster growth than normal (above the top line)
● Abnormal growth (irregular growth patterns)

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

Describe growth in animals

A

●Cell division occurs in all body cells. It occurs at a slower rate in adults that in younger animals as growth stops and cell division is only required for replacement and repair.
● Most cells differentiate at an early stage and become specialised. Some adult stem cells retain their ability to differentiate.

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

Describe growth in plants

A

●Cell division can only occur in meristematic tissue. The rate of cell division remains the same throughout a plant’s life.
● Meristematic stem cells can differentiate into any cell type for as long as the plant lives
●Cell elongation occurs in all cells. Cells expand and enlarge enabling growth of the plant.

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

What are stem cells?

A

Cells that are unspecialised and capable of differentiating into a range of different cell types

23
Q

What is meant by ‘differentiation’?

A

● The process by which stem cells become specialised (have a specific function)
● Some genes switch on or off, determining cell type

24
Q

Why is cell differentiation important?

A

It enables the formation of specialised tissues with specific functions e.g. muscle tissue.

25
Q

What are embryonic stem cells?

A

Stem cells found in very early embryos that are unspecialised and capable of differentiating into any cell type

26
Q

What is the function of embryonic stem cells?

A

Enable the growth and development of tissues in human embryos

27
Q

What are adult stem cells?

A

Stem cells that can differentiate into a limited range of cell types e.g. bone marrow stem cells

28
Q

What is the primary function of adult stem cells?

A

Replacement of dead cells e.g. replacement of red blood cells which only live for 120 days

29
Q

Where are stem cells found in plants?

A

Meristems

30
Q

Where is meristem tissue found?

A

In regions of the plant where cells are continuously dividing e.g. root tips, shoot tips

31
Q

What are meristematic stem cells?

A

Stem cells found in meristems that are unspecialised and capable of differentiating into any cell type during the life of a plant

32
Q

How can stem cells be used in medicine?

A

● Stem cells collected
● Stem cells stimulated to differentiate into specific cell types e.g. heart muscle cells
● Specialised cells transplanted into the patient
● Used to treat damage or disease e.g. heart disease

33
Q

Where can embryonic stem cells be collected from? (2)

A

● Donor stem cells removed from embryos grown in vitro
● Patient’s own stem cells removed from the umbilical blood before birth

34
Q

What are the benefits of using stem cells in medicine? (4)

A

●Treat damage or disease e.g. heart disease, type 1 diabetes
●Treat diseases that would otherwise be untreatable
●Used in scientific research
● Growing organs for transplants

35
Q

What are the risks of stem cell use in medicine? (6)

A

● Transplanted stem cells could cause tumours
● Finding suitable stem cell donors is a difficult task
● Stem cells may be rejected by the body (immunosuppressants taken)
● Potential side effects
● Long term risks of using stem cells unknown
● Stem cells may become contaminated during preparation and when transplanted transmit infections to the patient, making them sicker

36
Q

What are the ethical issues related to the use of stem cells in medicine? (2)

A

● The embryos that were used to provide stem cells are destroyed which is seen as unethical and a waste of potential human life
● May lead to the reproductive cloning of humans

37
Q

describe what happens to the cell’s DNA during interphase and explain why this process is necessary (2)

A

a cell’s DNA is duplicated (1), so that there will be one copy of the DNA for each new cell produced by mitosis (1)

38
Q

state the purpose of cell differentiation in an animal embryo

A

to produce specialised cells

39
Q

describe two differences between the growth of animals and the growth of plants (2)

A
  1. all growth in animals happen by cell division, animals don’t grow by cell elongation, but growth in plants occur by cell division and cell elongation
  2. animals tend to grow while they’re young, and then they reach full growth and stop growing, while plants often grow continuously.
40
Q

explain how a tumour forms

A

a change in one of the genes that controls cell division (1) causes cell to divide uncontrollably (1). this creates an abnormal mass of cells (a tumour) (1)

41
Q

describe the point at which a tumour is classes as a cancer (1)

A

when the tumour invades and destroys surrounding tissue (1)

42
Q

stem cells are ….

A

undifferentiated, stem cells are cells which have not yet differentiated to become specialised cells

43
Q

explain one reason why scientists may prefer to use embryonic stem cells for research rather than adult stem cells (2)

A

embryonic stem cells have the potential to produce any type of cell at all (1), whereas adult stem cells are less versatile (1)

44
Q

suggest one reason why people are against research involving embryonic stem cells. (1)

A

some people think it’s wrong to destroy a potential human life (1)

45
Q

scientists can also use plant stem cells in drug research. name the plant tissue that produces stem cells.

A

meristem tissue

46
Q

explain two potential risks of using stem cells to cure type 1 diabetes (4)

A

there may be a risk of tumour development (1) if the rate at which the new insulin-secreting cells divide inside the patient can’t be controlled (1). there may be a risk of disease transmission from the donor to the recipient (1) if viruses are present within the embryonic stem cells used to develop the new insulin-secreting cells (1)

47
Q

Advantages of bone marrow stem cells

A

Can treat many blood-linked or immune-linked diseases, less ethical concerns than embryonic stem cells, bone marrow is easier to obtain than embryonic cells

48
Q

Advantages of embryonic stem cells

A

No consent required, obtainable via embryos discarded in IVF, can be used to make any type of cell, less risk of rejection if used via therapeutic cloning

49
Q

Disadvantages of bone marrow stem cells

A

Requires voluntary donors, bone marrow extraction can cause pain to an individual and requires consent, may have a risk of infection, can only form cells such as blood cells, risk of rejection

50
Q

Disadvantages of embryonic stem cells

A

Ethical considerations such as potential loss of life or harm to embryo, less easily obtainable than bone marrow stem cells, risk of rejection

51
Q

Benign tumour

A

A lump of cells that cannot invade neighbouring tissues or spread throughout the body

52
Q

Malignant tumour

A

Lump of cells that have developed the ability to travel to other parts of the body

53
Q

Carcinogen

A

A cancer-causing substance

54
Q

Ionising radiation

A

Type of radiation such as UV, X-ray or gamma rays that can cause mutations in DNA

biology (8 decks)

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