Monday, 17 February 2014

What are two functions of apoptosis



Quiz 2
The following quiz is based on student presentations and discussions.


1.  What are two functions of apoptosis

a. ______________________________________________________________

b. ______________________________________________________________

2.  What are two different sorts of signals that force a cell into becoming apoptotic?
a. ______________________________________________________________
b. _________________________________________________________________


3.  The subcellular organelle most closely associated to the initiation of apoptosis is

a) Nucleus

b) lysosome

c) mitochondrion

d) endoplasmic reticulum

4. The difference between ordinary cell death and apotosis is:


5. What is the end-replication problem and what does it have to do with telomeres?






6. An older cell will necessarily have shorter telomeres than an young one? T/F

7. Fred has the telomere lengths of his cells chromosomes measured and it's found that they are shorter than the average for someone his age. This probably means that Fred

a. will die earlier than his same aged peers

b. had more cell divisions in his body than normal

c. has already activated his cellular death receptors

d. all of the above.

8. Describe what happens to a cell whose telomeres are shorter than the critical length.

9. The end-replication problem doesn't necessarily describe the cause of telomere shorting because of the presence of the enzyme called ___________________________________.



10. Osteoporosis
a. is limited to post-menopausal women
b. is caused by osteoblasts breaking down bone
c. is caused by osteoclasts not building new bone
d. is caused by a lack of female sex hormones in both men and women
e. none of the above

11. Bone is usually thought of as a defensive or support structure – but it also acts to store
a. __________________________ and
b. _______________________________________

12. Most heart disease is often believed to be caused by which underlying condition?


13. Medicines given to prevent a heart attack are popularly called ________________, although that is not really what they do.

14. Two changes associated with the aging heart are that it
1. ___________________________________________
2. ____________________________________________

15. The measurement of _______________________ is how a doctor can tell how high your blood glucose levels were for a couple of months before the assay.

16. The reason that older people develop type diabetes is because
a. they are unable to make enough insulin
b. the aging body produces proteins that remove insulin from the blood
c. old people eat more glucose than younger ones
d. obesity, over-eating and lack of exercise result in insulin-resistance

17. Three lifestyle factors the affect the initiation of most age-related diseases discussed are:
1.
2.
3.

18. Two age-related changes to the heart are:
1. ________________________________

2. ________________________________

19. Why are “old” cells (cells from old bodies) more likely to become apoptotic or senescent when exposed to radiation or other mutagens than younger cells?

20. Loss of both vision and hearing is found in older people- what is believed to be the mechanism common to both?


21. Cells that cause cells to fail to pass a checkpoint include

a) radiation

b) wrong number of chromosomes

c) DNA damage

d) all of the above


22. Essay 1 – The following is a paragraph from a treatise on osteoporosis:

"In summary, the multifaceted activities of estrogen are fully reflected in bone. Of the many surprises encountered investigating estrogen action in bone is the relationship among estrogen, the immune system, and the skeleton (Figure 3 not show here). Clearly, if this relationship is equally relevant in humans as in rodents, postmenopausal osteoporosis should be regarded as the product of an inflammatory disease bearing many characteristics of an organ-limited autoimmune disorder, triggered by estrogen deficiency, and brought about by chronic mild decreases in T cell tolerance. Why such a pathway should have emerged is intriguing. One explanation is suggested by the need to stimulate bone resorption in the immediate postpartum period in order to meet the markedly increased maternal demand for calcium brought about by milk production. The signal for this event is the drop in estrogen levels early postpartum. Henry Kronenberg (Harvard University, Boston, Massachusetts, USA) has suggested that postmenopausal bone loss should be regarded as an unintended recapitulation of this phenomenon (personal communication).Another response to delivery is the restoration of normal immune reactivity and the loss of tolerance to the fetus. It is tempting to speculate that cessation of ovarian function induces bone loss through an adaptive immune response because natural selection has centralized these 2 key adaptations to postpartum within the immune system. “

What does the author mean when he compares osteoporosis in terms intensified osteoclast activity and an abnormal immune response – what makes him suspect this?



23. Describe the progression of events that leads to atherosclerosis in numbered steps.

24.What effect does inflammation play in this process

25. What is the event that can lead to a myocardial infarction (heart attack) or cerebrovascular accident (stroke)?








26. What causes Alzheimer's disease? (Describe what happens on the cellular level and some possible causes.)


27. According to the figure below

a) Could growth factors contribute to a cell becoming apoptotic? If so, how so, if not why not?

b) what would you guess were the functions of fos and jun (found within the pink nucleus in the drawing). Were you right, why or why not?

c) What activates the PKA protein ?

d) Major pathways leading to apoptosis converge on “Mt” - what do you think that stands for and why?


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