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BIO 182 EXAM 2 EXAM (ACTUAL EXAM) WITH QUESTIONS WITH VERY ELABORATED ANSWERS CORRECTRY WELL ORGANIZED LATEST 2024 – 2025 ALREADY GRADED A+$13.99
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BIO 182 EXAM 2 EXAM (ACTUAL EXAM)
WITH QUESTIONS WITH VERY
ELABORATED ANSWERS CORRECTRY WELL
ORGANIZED LATEST 2024 – 2025 ALREADY
GRADED A+
Radiation
Energy gained by the sun is a form of heat that raises your body temperature.
Energy you radiate depends on how hot something is- this is why the sun radiates
more heat than something like us. We would radiate more heat to our
surroundings if we walk into somewhere cold because difference in radiation- we
would be losing heat by radiation in this case.
Conduction
The direct transfer of heat from one substance to another substance that it is
touching. Depends on the difference in temperatures- if a rock is hotter, the lizard
sitting on it will gain heat. If the rock was colder it would lose heat to the rock.
,Convection
The transfer of heat by the movement of a fluid over an object (air is a fluid).
Depends on the shape of an organism.
Directional Selection
The mean phenotype shifts in a particular direction
Disruptive Selection
The standard deviation of the trait increases as individuals with the mean value
disappear.
Stabilizing Selection Explained
The stronger the selective pressure against extreme phenotypes, the narrower
the distribution of phenotypes will be in future generations. In the end, the size of
the standard deviation will reflect both the strength of selection against extremes
and the frequency of mutations creating new variation. Thus, when we observe a
wide range of phenotypes in a population, we might infer weak selective pressure
against the extremes.
How many modes of selection are there?
3
What are the modes of selection?
Stabilizing selection, directional selection, and disruptive selection
,Stabilizing Selection
The mean of the trait remains similar over time but the standard deviation
decreases
Directional Selection Explained
The population's environment changes. The mean phenotype in the population
may no longer be the phenotype that reproduces the most. Over time, we should
expect the mean phenotype to shift higher or lower, depending on the direction
of selective pressure. Once the mean phenotype catches up to the change in the
environment, stabilizing selection will resume. The environment must change
slowly enough for the population to persist. If the environment changes too
quickly, no members of the population will be able to reproduce, leading to
extinction.
Disruptive Selection Explained
A population can occupy an environment in which individuals with extreme
phenotypes reproduce more than individuals with the mean phenotype.
This mode of selection occurs when several distinct strategies confer greater
reproductive success than other strategies do. Can produce new species when
individuals choose to mate only with similar-looking individuals. This non-random
mating prevents recombination from restoring intermediate phenotypes.
Evolution by Natural Selection
Heritable variation leads to differential reproductive success
Selection and Fitness
, Directional Selection Equation
y=bx+c
y=relative fitness
x= trait value
b= strength of selection
c=parameter
True or False? If the slope of the relationship between the phenotype and fitness
is positive, natural selection would decrease the phenotype over generations.
False, it would increase the value of the trait over time
Stabilizing Selection Equation
y=ax^2+bx+c
y=relative fitness
x= trait value
a/b= strength of selection
c= parameter
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