Standard 9!!!

Hardy-Weinberg Quiz
#2 

Question: After graduation, you and 19 friends build a raft, sail to a deserted island, and start a new population, totally isolated form the world. Two of your friends carry (that is, are heterozygous for) the recessive cf allele, which in homozygotes causes cystic fibrosis/ Assuming that the frequency of this allele does not change as the population grows, what will be the instance of cystic fibrosis on your island.

Known information:
20 people on island - so there are 40 alleles
2 are heterozygous - 2 recessive alleles in group 
p + q = 1

p² + 2pq + q² = 1

Calculations:

2 alleles / 40 alleles = q

q = .05 frequency

People who have cystic fibrosis must have two recessive alleles, or q² because the gene is recessive and only appears in those with two recessive alleles. Therefore, q² = .05² = .0025, or 0.25%

Evolution by Natural Selection Quiz
#15

Question: Do you think that evolution by natural selection is occurring in this cactus population? Explain why or why not.

Answer: Yes, the right cactus survived and will be able to produce because of its mutation, spikes, that will then be passed on to its offspring. The left cactus, however, did not have this mutation, which made it more vulnerable to being eaten by an animal. Because it was eaten, it will not be able to reproduce and have offspring. Therefore, there will be more cacti with spikes and less without spikes.

Quiz  #1B Basic Chemistry
#4

Question: What is the maximum number of covalent bonds an element with atomic number 8 can make with Hydrogen?

Answer: Two Covalent Bonds.

Explanation: The element Hydrogen has two electrons, therefore both remain in its outer layer. An element with an atomic number of eight would have eight electrons, 2 in its inner shell, and six in its outer shell. The octet rule states that every element wants to have eight electrons in its outermost shell, in order to be most stable. Therefore, an element with an atomic number of eight will want to have two covalent bonds to fill its outermost shell and become stable.

Honors Biology Unit 1 Test
#9 

Question: What is the reason why hydrocarbons are not soluble in water?

Answer: The majority of their bonds are non-polar covalent carbon to hydrogen linkages.

Explanation: Water's polarity works to break down substances by using its positive side to attract the positive side of other polar molecules, and its negative side to attract the negative side of other polar molecules. However, because hydrocarbons are not polar, the water cannot use this method to break it down because it cannot attract it.

Allele Frequencies

Today we learned about the frequencies of different alleles in different populations. We learned how to calculate the frequency using two equations : p² + 2pq + q² = 1 and p + q = 1. We experimented with this by having four alleles and mating with other members of our class randomly. We also experimented with genetic drift, by separating our class in half and only mating within our half. We noticed that one population’s frequencies stayed the same, and the other population’s frequencies changed to having more dominant alleles than recessive.

My original four alleles.

Tiger Lab

Today we did a lab involving dominant and recessive genes in Tigers. The recessive gene in this case was lethal, not having any hair to keep it warm in winter. We had 25 recessive and dominant genes, and randomly “mated” tigers in a bag. As we pulled out pairs of genes, we noted whether they had the dominant gene (HH or Hh) or the recessive gene (hh). As those with the recessive gene died off, the number of h in our society grew very small. However, this number never completely disappeared. This same trend happens in real life, recessive genes can never completely die out, they are just hidden by the dominant genes.

Our final results.

Parent's Day

Today, Parent’s Day, we discussed how physical features can affect who you will mate with. We tested this by looking at a pictures, each was the same person side by side, but one was slightly altered to make the person look more masculine or feminine. We discovered that men will always view more feminine women as more attractive, because they have higher levels of estrogen. We also discovered that women will view more feminine women as more attractive because we are aware of their high estrogen level and automatically view them as competition. When it came to deciding between men, the results were varied. Women that are ovulating found more masculine men more attractive, because they want to reproduce with the most masculine, high in testosterone male. However, when women are not ovulating, they often find a more feminine male as more attractive because they view him as being softer and more loving. Males that are self-confident and sure of themselves view masculine men as more attractive because they do not see them as a threat to their self-esteem. However, men who are not as confident will view more feminine men as more attractive because they don’t threaten them.

Brine Shrimp Lab

Today we began our brine shrimp lab, which explores mutations in a species population of brine shrimp. We created 30 mL of 0%, 0.5%, 1%, 1.5% and 2% NaCl water. We put these waters into separate Petri dishes and labeled the lids. We then put a short piece of tape on a slide and used a paint brush to put roughly 20 eggs on these. Next we counted the eggs using a microscope to count and record how many each had. We placed these in the water. After 24 hours, we came back, recorded the number living, and extracted them. After another 24 hours, we did the same. We noticed that a molarity of .5% water had the highest number of brine shrimp that lived. This showed that the mutation to live in .5% water was the most common in our population. However, some shrimp in the population were mutated to survive in all the other waters as well, just not as high of a percentage.

Two of our labeled petri dishes with brine shrimp.

A really bad picture of brine shrimp eggs.

Really tiny living brine shrimp.

Beginning the Paleo Project

     Today in class we began with a short quiz, which was review, and a discussion on the book which talked about plant life, and different adaptions plants have made and why. 
     After this we began our Paleontology Project, my partner and I chose a seal (or pinniped) and a Puijila. Our job is to create a transitionary fossil between the two, describe the fossil, draw a picture, and then plan an elaborate trip to go and search for the fossil.