Toothpick Fish Lab Response

Twelve fish moved into a pond, bringing along twenty-four alleles for scale color: eight green, eight red, and eight yellow. Out of the fish, most fish were green, because green is the dominant allele. In the pond history (before the environmental disaster), 57.7% (26/45) of the fish was green. That is more than half of the fish. In twelve fish, there could be a maximum of eight green fish and a minimum of four green fish. Eight green fish can be achieved with all green fish being heterozygous, and four green fish can be achieved by all green fish being homozygous. After green fish, orange fish were the most populous. 28.8% (13/45) of the fish in the history of the pond were orange. In twelve fish, there could be a maximum of eight orange fish and a minimum of zero. Eight orange fish can be achieved by having all red alleles pair up with a yellow allele, and there could have been zero orange fish if no red alleles pair up with a yellow allele. Red and yellow alleles are incompletely dominant (orange) and are recessive to green alleles. There could be a maximum of four red/yellow fish if all fish are homozygous and there could be a minimum of zero red/yellow fish if each red allele pairs up with a yellow allele or if some red/yellow alleles are paired with green alleles. Now, there weren't always twelve fish after the first generation, because in the first generation, there was a yellow fish. That fish couldn't hide well in the green algae and was eaten. The population dropped to eleven for future generations, but luckily, the second and third generations had no yellow fish, so the fish count stayed at eleven. In the fourth generation, though, the environment changed due to a disaster and the green fish were now having trouble hiding. Six green fish (54% of total fish) died because of that, bringing the fish total to five. Green alleles were completely wiped out because green alleles are dominant and if a green allele is present, the fish will be green. In the end, five fish survived: one red, three orange, and one yellow.

The lab can be changed in many ways. The habitat can be different. It can first be rocky, where all of the green fish are eaten, then in the algae that grows back, maybe only green fish can hide well. Then the remaining fish would die, too, and the population would go to zero. then the animal that eats the fish would die, too, and the organism that the fish eats would rise in population. There might be no disaster, but the homozygous green fish might have a 50% chance of carrying a disease that makes them slow, so half of the homozygous green fish might be eaten. There wouldn't be as many green fish as there was (but some homozygous and heterozygous green fish might survive). no matter how you change the lab, the end result will always be different.

The Mysteries of Punnett Squares

A Punnett square is a basic tool in genetics being explored in class . It helps determine the probability of a characteristic showing. To fully use a punnett square, though, you must understand a few terms in genetics, such as traits(characteristic, represented by two alleles), alleles(unit that helps determine trait), homozygous(having two of the same alleles for a trait), heterozygous(having two different alleles for a trait), dominant and recessive [alleles], genotype(type of alleles[can be represented by homozygous and heterozygous]), and phenotype(characteristic showing for a trait). Dominant alleles are alleles whose respective characteristic is are always expressed and recessive alleles are alleles whose respective characteristics are hidden when a dominant allele is present.

Punnett squares come in different levels. A mono-hybrid Punnett square is basically a square split into four parts. The mother's two alleles for a trait go on top of the Punnett square, one on top of each column, and the father's two alleles for the same trait go to the left of the Punnett square, one for each row. After that, in each box, copy the mother's allele from the top and the father's allele from the left. You should get a filled Punnett square. You will see that there is an x/4 probability of a certain genotype or phenotype. For example, if mom has a TT for rolling tongue and dad has Tt, they both can roll their tongue. You can see there is a 2/4, or 50% chance of getting homozygous dominant alleles, 50% chance of getting heterozygous alleles (genotype), and 4/4, or 100 chance that the child can roll their tongue (phenotype).
The mono-hybrid Punnett square shows the probability of different distributions of alleles for a single trait, with each box standing for one trait.



Sometimes, you will get two alleles for a trait where one allele isn't dominent over the other or vice versa. That is a situation of incomplete dominance or codominance. In incomplete dominance, there is a blend of both traits, while in codominance, both traits show partially. Incomplete dominance is represented by a capital letter for one allele(F) and the same capital letter with an apostrophe for another allele(F'). Codominance is represented by two different capital letters(B)(G). You set up the punnett squares for these cases the same way and fill it in the same way. If the alleles are homozygous, there is no difference. Only if it is heterozygous does incomplete/codominance come into play.

We have taken the Punnett squares to the next level as di-hybrid and tri-hybrid. Di-hybrid Punnett squares show the probability of each distribution of TWO traits(four alleles) possible with the parents. If the mother had BB for eye color and Ss for skin color, her alleles in a di-hybrid Punnett square would look like TS Ts TS Ts on top of the 4 columns. Those are all of the possibilities when getting sets of two.You do the same for the father and set up your 16 square Punnett square. Each square contains the alleles for two traits. The probability of getting the desired two trais will be x/16.

The tri-hybrid show the probability of the distribution for three traits. If the mother also had Hh for hair color, you can add on to the di-hybrid method. For the mother, you get TSH, TSh, TsH, Tsh, TSH, TSh, TsH, Tsh as the allele combinations for each column. You do the same for the father and set up the 64-square punnett square, with each box representing three traits. There will be an x/64 chance for a desired result.

I found that if you want to go farther, you can multiply probabilities from mono-hybrid punnett squares. If you want the probability of having two parents heterozygous for brown eyes,
black hair, A blood type(over O), and six fingers produce a baby with blue eyes, blonde hair, O blood type, and five fingers, multiply individual probabilities.
1/4 * 1/4 * 1/4* 1/4 = 1/256 = .390625%

That is the probability of getting that kind of baby.



A shortcut I found is that if you have homozygous alleles, only one needs to be represented. If mom had TT and dad had Tt, you only need to set up one column(the second will be the same).

This works for di- and tri- hybrid punnett squares.



All of this I learned or discovered in class. I feel really interested in genetics. I find I work well with punnett squares.



p.s. I couldn't include punnett squares for the example problems because of the limitations of blogger(it kept moving the Punnett squares). For example:



R r

R RR Rr

r Rr rr



should have been a Punnett square.

Green Blob in Space

The green blob in space that the Hubble captured seems to be interesting. It shows that there is activity inside the blob; new stars are forming. What is actually happening is that the pressure from collapsing (and condensing) hydrogen inside the blob is creating new stars. The stars aren’t part of an existing galaxy, though. The fact that there is a black hole powering the quasar (a bright object full of energy) and the fact that every (or at least the Milky Way) galaxy revolves around a powerful black hole leads me to believe that a new galaxy is being born. Every galaxy might have started out as a blob, and it makes sense too. The Big Bang could have scattered hydrogen blobs across the universe that eventually formed new galaxies. With a little bit of digging into the facts, who knows? My hypothesis could hold true.

The Yahoo! article

Adaptation (Camouflage)

These pictures show an example of camouflage. In the first picture, taken at the vantage point of me and any predator, it is almost impossible to spot this insect. (approximately in the center of the picture) The insect is just small and being brown, is not visible against the green. This color makes it easy for the insect to hide in greens and browns(trees, dirt). You can only spot this insect if you know what it is and where it is. This insect is so good at hiding that it took me around 5 minutes to find it with my mother and sister pointing at it. This insect can easily avoid a predator's gaze.

Thanks to my mother and sister for telling me there was an insect in that plant.

Biotic Limiting Factor (Squirrel)

These are pictures of squirrels I found around my house. They are limiting factors because they limit the amount of nuts that are buried. Seeds are buried by the squirrel and dug up as they are needed. If the squirrel doesn't dig up a nut, that seed will root and grow. The tree in the above picture is a limiting factor because it limits the number of squirrels that can use it as a shelter.

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Special thanks to my mother and sister for alerting me to the squirrels.