Login

Join for Free!
117530 members


hey!!! can someone check this for me? thanks

Discussion of all aspects of cellular structure, physiology and communication.

Moderator: BioTeam

hey!!! can someone check this for me? thanks

Postby bobs » Mon Apr 03, 2006 10:01 pm

Hi can someone please check this for me !! thanks :wink: :D
1. Which of the following cell types cannot become cancerous once they reach maturity?

A. Liver cells
B. Skin cells
C. Erythrocytes
D. Cardiac muscle cells
My Answer: C

2. Cigarette smoke is a carcinogen because it increases the likelihood of cancer by affecting the gene that regulates cell growth. Based on this information, a carcinogen is a substance which

A. promotes cell growth
B. promotes normal cell division
C. induces abnormal cell division
D. inhibits blood circulation in cancerous tissue

My Answer: A

Use the following information to answer the question

The following statements could be made about cancer cells.
1. They are well differentiated.
2. They are poorly differentiated.
3. They highly resemble the cells from which they originate.
4. Cells can enter and leave blood vessels.

3. Which statements are correct?

A. 1 and 2
B. 2 and 3
C. 2 and 4
D. 3 and 4

My Answer: C


4. The term metastasis refers to

A. a mass of cells actively dividing
B. a mass of cells not actively dividing
C. abnormal cell growth which is localized
D. spreading of cancer cells to other parts of the body

My Answer: D

6. Growth in normal cells is controlled by proteins called growth factors. They bind to a receptor on a cell’s surface. The binding produces another protein which controls the cell cycle. A mutagen can cause a change in this protein which activates it without a trigger from the growth factor and the receptor. One effect of this change might be

A. development of a malignant tumor
B. a decrease in the rate of cell division
C. a decrease in the diameter of malignant cells
D. a decreased rate of DNA replication in the cells
My Answer: A

7. During an investigation, a research assistant found that a chemical interfered with the cell metabolism during the phase of the cell cycle in which DNA is duplicated. A possible conclusion of this finding could be that the chemical

A. results in malignant tumour
B. will produce a benign growth
C. results in metastasis of cancer
D. can be used in the treatment of cancer
My Answer: D

8. HIV is a retrovirus. That is, its traits are encoded in RNA rather than DNA. RNA is not incorporated into the DNA of the host cell, yet the virus invades the host cell’s genetic code just as a DNA virus does. Retroviruses contain a special enzyme called reverse transcriptase which functions in this invasion. It thus appears that the function of transcriptase is to

A. prevent DNA replication
B. prevent protein synthesis
C. transcribe RNA into DNA
D. transcribe DNA from RNA
My Answer: C

The random list of steps by which HIV destroys helper T-cells follow.
1. Phagocytosis
2. Joining of HIV and helper T-cell DNA
3. Reverse transcription if HIV RNA
4. Reproduction of viral RNA
5. HIV recognition of helper T-cell binding sites

9. The correct order of these steps is

A. 1, 2, 3, 4, 5
B. 2, 5, 3, 4, 1
C. 5, 1, 3, 2, 4
D. 5, 1, 2, 4, 3
My Answer: C

10. HIV is not detected by the human immune systems for a variety of reasons. One reason is that HIV

A. is entirely engulfed by helper T-cells
B. mimics the cell membrane of human helper T-cells
C. moves around in the blood stream too rapidly for helper T-cells to find it
D. chemically blinds helper T-cells so that they do not recognize pathogenic materials

My Answer: B
bobs
Garter
Garter
 
Posts: 10
Joined: Mon Apr 03, 2006 9:58 pm

Postby mith » Mon Apr 03, 2006 11:02 pm

I'd disagree with 2, you could probably get more specific than just growth...
For example in acute leukemia, you have a large amount of immature wbc's being produced.
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;
~Niebuhr
User avatar
mith
Inland Taipan
Inland Taipan
 
Posts: 5345
Joined: Thu Jan 20, 2005 8:14 pm
Location: Nashville, TN

Postby bobs » Mon Apr 03, 2006 11:56 pm

so the rest are right?
bobs
Garter
Garter
 
Posts: 10
Joined: Mon Apr 03, 2006 9:58 pm


Postby MrMistery » Fri Apr 07, 2006 5:52 pm

1.NO, it's A, erythrocites can't divide, so can be cancerous.
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter
User avatar
MrMistery
Inland Taipan
Inland Taipan
 
Posts: 6832
Joined: Thu Mar 03, 2005 10:18 pm
Location: Romania(small and unimportant country)

Postby canalon » Fri Apr 07, 2006 8:16 pm

MrMistery wrote:1.NO, it's A, erythrocites can't divide, so can be cancerous.

No He's right, read again the question. Erythrocytes cannot divide hence cannot become cancerous once mature.
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)
User avatar
canalon
Inland Taipan
Inland Taipan
 
Posts: 3909
Joined: Thu Feb 03, 2005 2:46 pm
Location: Canada

Postby MrMistery » Fri Apr 07, 2006 8:53 pm

Ups, sorry, i've mastered many aspects of biology, but reading is still a problem for me.
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter
User avatar
MrMistery
Inland Taipan
Inland Taipan
 
Posts: 6832
Joined: Thu Mar 03, 2005 10:18 pm
Location: Romania(small and unimportant country)


Return to Cell Biology

Who is online

Users browsing this forum: No registered users and 2 guests

cron