WHICH SUBSTANCE IS THE MOST COMMON IN CELLS?

29 Jul WHICH SUBSTANCE IS THE MOST COMMON IN CELLS?

The biology of Aging

1. One condition that seems
to lead to senescence and not apoptosis in stem cells is

a. shortening of telomeres below
a critical limit

b. base damage to DNA

c. unequal division of
chromosomes at anaphase

d. none of the above

2. Knowing that even in the
oldest people’s stem cells seem to have many cell divisions left to them when
cultured in vitro (in a dish), the you might contend that a possible reason for
that was

a. Absence of inhibitory factors
found in the old bodies in the new culture
medium

b. factors in the cellular
environment of old people’s bodies

c. The presence of high levels of
growth factors in the culture serum

d. All of the above

3. In 1962, Leonard Hayflick
conducted an experiment that supported Weismann’s Theory of programmed death.
He proposed The Hayflick Limit which can be reached faster by:

a. Increasing the rate of cell
division

b. Underfeeding cells

c. Decreasing the rate of
mutations

d. Synthetically elongating
telomeres.

4. The antagonistic pleiotropy
theory of aging assumes that each gene has only one effect on the phenotype of
an organism at different stages of its life.True or False

5. In Conboy’s study on
heterochronicparabiotic pairs, which phrase described what future studies should
focus on according to the results of this study?

a. adult stem
cells

b. changes in aging cells

c. muscle cell regeneration

d. changes in aging plasma

6.- 7. Briefly explain what
happened to old stem and progenitor cells in a young systemic environment. (2
Sentences)

8. Which substance is the most
common in cells?

a. carbohydrates

b. salts and minerals

c. proteins

d. fats

e. water

9.
– 11. Describe how an enzyme may change the transcription patterns
of a cell by adding chemical groups to histone proteins. What is this called (2
Sentences)

12. Acetyl L-Carnitine/Alpha
lipoic acid are ____________ that are produced naturally by the body in _______

a. Amino acids, large amounts

b. Antioxidants, small amounts

c. Toxins, abundance

d. ROS, trace amounts

13. Most genes that determine
lifespan in C. elegans are directly in DNA repair. True or False

14.- 19. What is the preferable
study group in mammalian testing of aging interventions and explain why. Mice
or monkeys? Why?(2 Sentences)

20. The ____________
____________ theory , states that there exists a biological clock and a time
dependent plan or program that directs a limitation to a lifespan?

a. DNA damage

b. Evolveabity Theory (programmed
aging)

c. Mutation-accumulation

d. free radical

21. – 24. Unlike inorganic
objects like rocks or even computers (at present), living organisms can repair
damage or rebuild or even recycle damages at teh cellular. Give threeinstances
cellular systems involved in repairing cellular damages. (3 Sentences)

25.. An often given example of
antagonistic pleiotropy, and seems to fit the definition is

A.
Cellular senescence

B.
Apoptosis

C.
Cellular reproduction

D. None
of the above

26. In general stem cells ability
to reproduce (proliferate) declines with age? True or False

27. Studies using micro arrays
have the benefit that

a. they are automated

b. they are quantitative

c. they examine thousands of
genes simultaneously

d. they do everything on the
lines above

28. Studies of transcription
patterns across an animal’s lifetime only make sense if

a. the animals were born at the
same time

b. the rates of transcription are
identical

c. the same tissues are examined
each time

d. protein synthesis mirrors
transcription

29. – 30. What are the effects of
senescent cells on the aging body, why don’t they have the same effects in
young bodies?(2 Sentences)

31. The experiments in
heterochronic (cross-age) transplantation showed that

a. younger stem cell populations
out-competed older cells when transplanted into young recipients

b. stem cells derived from older
donors out competed young stem cells from the same young animal

c. the age of the recipient was
more important than the age of the donor in a heterochronous transplantation
experiment

d. none of the above

32. – 37. What was surprising in
the results of the longitudinal studies of Chambers et al. (and earlier Rossi
et al) in which microarray analysis of hematopoietic stem cells revealed
thatmake some people doubt that homeostasis living systems strive for homeostasis?
(4-5 sentences)

38. – 42. What do the studies of
such progerias as Huntington-Gilford progeria and Werner’s syndrome tell us
about normal aging? Explain (4-5 sentences)

43. – 48. Here are three quotes
from an printed interview with Francis Collins (look him up),

i. ” Collin’s lab team found
that in cells growing in the lab, when they used a chemical to un-cap the
chromosome ends, it altered gene splicing and led to progerin production and

cellular senescence.

ii. “It’s clear that progerin turns
on as a cell is approaching senescence,” Collins said.

Collin’s lab team found that in
cells growing in the lab, when they used a chemical to un-cap the chromosome
ends, it altered gene splicing and led to progerin production and cellular

senescence.

iii. “While I can’t prove it, it
seems likely that progerin itself is part of normal, programmed senescence,”
Collins said. “If we understood that, maybe we would be able to come up with

a strategy to deal with the
process of normal aging.”

a) We’ve heard that before, that
gene splicing alters with age – what does that mean? (2 sentences)

b) According to statement ii,
they were comparing artificially made senescent cells to the cells of people
with what condition?(2 sentences)

c) When stating that progerin
production is part of normal aging, what theory of aging is he implicitly
endorsing?n Why?(2 sentences)