Brainscape's Knowledge GenomeTM

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


See full index

BIOC192 > Lecture 18: WHAT ARE RECESSIVE AND DOMINANT MUTATIONS? > Flashcards

Lecture 18: WHAT ARE RECESSIVE AND DOMINANT MUTATIONS? Flashcards

1
Q

When is a mutation a germline mutation?

A

If a mutation occurs in a cell that go on to make gametes (eggs or sperm), the mutation can be passed on to the next generation (in born errors of metabolism)

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

Where do somatic mutations occur?

A

In other cells and cannot be passed on

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

How many cells is the human body made up of?

A

Approximately 37 trillion

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

What does a human cell normally do?

A

Grow and divide to form new cells as the body needs them (balance and homeostasis)

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

What happens when cells grow old or become damaged?

A

They die and new cells take their place

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

What is cancer?

A

A collection of related diseases and can start almost anywhere in the body

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

What are cancer cells?

A

Cells within a tissue that no longer respond to many of the signals that control cellular growth and death

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

What happens to cancer cells over time?

A

They become increasingly resistant to the controls that maintain normal tissue - and as a result they divide more rapidly

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

What do cancer cells evade?

A

Programmed cell death despite their multiple abnormalities

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

What happens in the late stages of cancer?

A

Cells break through normal tissue boundaries and metastasise (spread) to new sites in the body

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

What is cancer a result of?

A

An accumulation of mutations

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

What are most cancer mutations associated with?

A

DNA replication

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

What happens the more times a cell divides?

A

The more likely it is to gain a mutation - this is why the incidence of cancer is greatly increased with age

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

How many genes encode proteins that normally regulate cell growth and division?

A

Hundreds

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

What can lead to cancer?

A

Mutations that alter the genes regulating cell growth and division in somatic cells

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

What may mutations be?

A

Spontaneous (occur by chance) or the result of exposure to a mutagen (carcinogen) such as smoking or UV radiation

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

What are the types of genes that cause cancer when mutated?

A

Tumor suppressor genes and oncogenes

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

What do tumor suppressor genes encode?

A

Proteins that normally prevent uncontrolled cell growth

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

What are examples of tumor suppressor genes?

A

proteins that inhibit cell division and prevent other mutations (DNA repair enzymes)

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

What can lack of tumor suppressor genes do?

A

Stimulate cell growth

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

What type of mutations occur in tumor suppressor genes?

A

Recessive

22
Q

What do oncogenes encode?

A

Proteins that promote cell growth

23
Q

What are examples of oncogenes?

A

Proteins that stimulate cell division. Cancer mutations increase the activity of these genes

24
Q

What type of mutations occur in oncogenes?

A

Dominant

25
Q

What happens to the cell normally?

A

It is prevented from undergoing cell division, due to E2F transcription factor being bound to RB protein in the cytoplasm

26
Q

What happens when the signal for cell division is detected by a receptor?

A

A kinase is activated which adds a phosphate to RB protein. This initiates a conformational change, releasing E2F transcription factor into the nucleus so cell division genes can then be expressed

27
Q

What does a loss of function get in both copies of the RB gene do?

A

Cause activation of the E2F transcription factor

28
Q

What does a loss of function mutation in the p16 gene cause?

A

Activation of the E2F transcription factor

29
Q

What is a proto-oncogene?

A

A normal gene that when mutate can promote uncontrolled cell growth

30
Q

What do mutations that increase transcription in the promoter region cause?

A

An excess production of normal growth stimulating protein causing increased cell growth

31
Q

What do mutations that increase protein activity in the coding region cause?

A

A protein to always be active or not be degraded causing increased cell growth

32
Q

What chromosomal changes can cause increased cell growth?

A

Gene duplications and translocation

33
Q

What can gene duplications cause?

A

Increased protein production and cell growth

34
Q

What is translocation?

A

When a piece of one chromosome fuses with a piece of another chromosome and can increase cell growth

35
Q

What is chronic myeloid leukaemia an example of?

A

How oncogene and tumor suppressor mutations lead to cancer

36
Q

What happens in chronic myeloid leukaemia?

A

A break in chromosome 9 fuses with a break in chromosome 22 to form a Philadelphia chromosome where BCR gene infused to ABL gene

37
Q

What is the ABL gene under control in the Philadelphia chromosome?

A

The BCR promoter region so it isn’t regulated how it should normally be

38
Q

What is the oncogene in chronic myeloid leukaemia?

A

BCR-ABL gene

39
Q

The new BCR-ABL gene is …

A

always active

40
Q

What does the norma BCR-ABL gene need?

A

A cellular signal to activate it so it can promote cell division

41
Q

What can the BCR-ABL gene do?

A

Promote cell division without a signal

42
Q

What is needed to cause uncontrolled cell division and cancer?

A

A functional tumor suppressor gene will prevent cancer so mutations in both copies of RB tummy suppressor genes and the oncogene are needed

43
Q

What do inherited mutations do?

A

Increase chance of cancer because it is one less mutation which needs to occur

44
Q

What are the types of cancer treatment?

A

Surgery, radiation therapy, chemotherapy and target therapy

45
Q

What happens in surgery?

A

Cancer cells are removed

46
Q

What happens in radiation therapy?

A

Targeted radiation treatment to kill cancer cells

47
Q

What happens in chemotherapy?

A

Uses drugs that target dividing cells as cancer cells grow and divide rapidly but it also affects normal cells

48
Q

What is an example of chemotherapy?

A

Mercaptopurine

49
Q

What is Mercaptopurine?

A

A DNA base analog that inhibits with enzymes that make dATP and dGTP nucleotides needed for cell division

50
Q

What is used in target therapy?

A

Drugs that target changes in caner cells that allow them to grow and divide

51
Q

What is an example of target therapy?

A

Gleevac

52
Q

What does Gleevac do?

A

Inhibits kinase activity of BCR-ABL protein

BIOC192 (38 decks)

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