CHEM 3212 – Biochemistry UPDATED
ACTUAL Questions and CORRECT
Answers
Major determinants of current human evolution include all except:
Select one:
a. Relaxation of natural selection.
b. Robust geological changes.
c. Human culture.
d. Available resources such as food. - CORRECT ANSWER- ✔✔b. Robust geological
changes
When environment changes rapidly resulting in a large reduction of a population size, the
propagated traits occur via the
Select one:
a. bottleneck effect.
b. founder effect.
c. genetic drift effect.
d. extinction effect. - CORRECT ANSWER- ✔✔a. bottleneck effect
Which of the following is considered a phenotype?
Select one:
a. Eye color
b. Metabolic syndrome
c. Cancer
d. Skin color
e. All of the above - CORRECT ANSWER- ✔✔e. All of the above
When environment changes rapidly resulting in a large reduction of a population size, the
propagated traits occur via the - CORRECT ANSWER- ✔✔a. bottleneck effect. (correct)
b. founder effect.
,c. genetic drift effect.
d. extinction effect.
quorum sensing - CORRECT ANSWER- ✔✔quorum sensing or quorum signaling is the
process of cell-to-cell communication that allows bacteria to detect and respond to cell
population density by gene regulation, typically as a means of acclimating to environmental
disadvantages.
Cell theory states - CORRECT ANSWER- ✔✔All living things are made up of cells, cells
are the basic units of structure and function in living things, new cells are produced from
existing cells
Cell theory - three aspects - CORRECT ANSWER- ✔✔Classical cell theory contains three
explanations about cells. These principles are: cells are the basic unit of life, all living things
are made up of cells, and all cells come from other cells. Cells cannot spontaneously
generate, or arise from non-living matter.
stabilizing selection in biology - CORRECT ANSWER- ✔✔occurs when there is selection
pressure again phenotypic extremes, and "intermediate" or "average" phenotypes are more
likely to survive. It can be considered as Goldilocks selection, which is not too big, not too
small, just right.
What are the features of stabilizing selection?
Stabilizing selection results in a more homogenous and phenotypically uniform population. If
any outliers are selected against, with time most of the population will have the same fit
phenotype.
What is stabilizing selection in biology?
Stabilizing selection is a form of natural selection wherein individuals with moderate or
average phenotypes are more fit (more likely to survive and reproduce). This form of
selection picks against phenotypic extremes (e.g. the largest and the smallest are less fit).
What is an example of stabilizing selection?
Human birth weight — If babies are born too small they are more likely to die, but if the baby
is too large, there can be complications during childbirth.
Numbers of eggs in a nest — If there are few eggs, then maybe all the chicks will die.
However, if there are too many eggs, then the parents can't feed them all, lowering the
chances of survival.
, direct selection - CORRECT ANSWER- ✔✔Directional selection does the "heavy lifting" of
evolution by tending to move the trait mean toward the optimum for the environment. It
results in increased adaptedness of organisms. It is the principle process that Charles Darwin
himself envisaged as driving adaptive evolution. Two of Darwin's own examples were (1)
faster wolves being more successful at hunting deer, and (2) flowers that produce more nectar
being more successful in attracting pollinating insects. These both suggest directional rather
than other forms ("modes") of selection. Directional selection is the process that comes most
easily to mind when thinking about natural selection, and it is the form of selection that has
taken place in the best-known examples of evolution (e.g., the peppered moth, antibiotic
resistance, finch beaks). However, directional selection does not always result in evolution,
because it can be constrained in many ways. If directional selection acts in different
directions in different populations or species, because of variation in environmental
circumstances, then it is described as divergent. This results in populations becoming
different, and it can contribute to speciation. Directional selection can also be artificially
imposed, and it has commonly been used by animal and plant breeders to improve traits (such
as yield) in domesticated organisms, as well as to better understand evolution. This
bibliography first deals with natural directional selection, and then moves on to address
artificial selection.
disruptive selection - CORRECT ANSWER- ✔✔form of natural selection in which a single
curve splits into two; occurs when individuals at the upper and lower ends of a distribution
curve have higher fitness than individuals near the middle
homestatic selection - CORRECT ANSWER- ✔✔Natural selection might act on homeostatic
regulatory mechanisms and control mechanisms including homeodynamics, allostasis,
hormesis and homeorhesis, where different stable stationary states are reached. Regeneration
is under homeostatic control through hormesis.Many homeostatic mechanisms, like
temperature, have different responses if the variable is above or below the set point. When
temperature increases, we sweat, when it decreases, we shiver. These responses use different
effectors to adjust the varia
Polymorphisms are genetic variations within a specific species.
Select one:
a. True
b. False - CORRECT ANSWER- ✔✔a. True
If an organism's environment changes so that a particular phenotype is no longer useful, that
particular trait may be eliminated through the process of
Select one:
