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Discussion of everything related to the Theory of Evolution.

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someone
Garter
Posts: 1
Joined: Thu Jun 19, 2008 1:39 pm

### Help

I am quite weak in this and would be great if i could have the answers for these questions or even notes on evolution
Hardy-Weinberg Law Problems

1.
Screech owls are found in two different colour patterns: red and gray. Scientists have raised and bred
these owls in captivity. The scientists mated red to red, red to gray, and gray to gray. The red to gray
matings usually gave equal numbers of red and gray offspring, but sometimes gave only red offspring.
A population survey done in Pennsylvania showed the population to be composed of 51% red and 49%
below.

a) Which gene is dominant and which gene is recessive? How can you determine this?
b) Calculate each allele frequency.
c) Suppose the frequency for red feathers is 0.42 ten years later in the same population. What could
have caused the change in the gene frequency?
d) What is the percentage of heterozygous owls?

2.
The ability to taste a chemical substance called PTC is the result of inheriting a dominant gene (P).
Humans that are hybrid (Pp) for the gene are also tasters. Humans that are pure recessive cannot taste
PTC. A population sample was taken in a small town and of 1092 people tested 64% were found to be
tasters.
a) How many people in the sample can taste PTC?
b) What is the frequency of each allele?
c) What percent of the population are heterozygous? How many people are heterozygous?
d) What percent of the population are homozygous dominant? How many people are homozygous?
e) A sample was taken in the same town 15 years later and the allele frequencies were found to be
the same as in the earlier sample. How can you account for this result?

3)
One in 1700 US Caucasian newborns have cystic fibrous. C for normal is dominant over c for cystic
fibrous. What percent of the population is homozygous dominant, and thus not carrier of the disease?

4. If 9% of an African population is born with a severe form of sickle-cell anemia (ss), what percentage of the
population will be more resistant to malaria because they are heterozygous(Ss) for the sickle-cell gene?

mith
Inland Taipan
Posts: 5345
Joined: Thu Jan 20, 2005 8:14 pm
Location: Nashville, TN
Contact:
wish I paid attention in class
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;
~Niebuhr

February Beetle
King Cobra
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Joined: Wed Sep 21, 2005 2:47 am
Location: Kansas
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I'm sure this person wishes they did, too.

Man in civilization surveys the creature through the glass of his knowledge and sees thereby a feather magnified and the whole image in distortion. - Henry Benson

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