Virtual Punnett Square Lab

While doing a virtual Punnett Square lab in biology, I learned many things. For example, the correct way to show the results of a creature's probable alleles is to write it like this: #Homozygous Dominant: # Heterozygous Dominant: # Homozygous Recessive. Writing in this standard way helps people understand the actual probability and outcome of a genotype.

The lab is a really helpful way to learn. While trying to find the possible genotypes and phenotypes of generations of animals based off of only their parental generation's genetics, I learned a lot about alleles and genes in an animal. It can teach anyone, from beginners to scientists. The results of the lab are displayed below.

Mitosis: The Movie

After making a stop- motion animation about mitosis which can be accessed here, I answered questions about mitosis. Here they are.

• If a cell contains a set of duplicated chromosomes, does it contain any more genetic information than the cell before the chromosomes were duplicated?

It will have more DNA (greater quantity), but nothing new (same quality). While its DNA is double in amount, it has the exact same genetic code as itself and the other identical DNA strand. Therefore, it has the exact same information and contains nothing new.

• What is the significance of the fact that chromosomes condense before they are moved?

This stage allows the cell to split properly, with 50% of everything going into one half, and 50% in the other half. If they didn't condense, the chromosomes could not have been pulled apart correctly, meaning the cells could be uneven, which is bad. This would create many genetic mutations.

• How are the chromosome copies, called sister chromatids, separated from each other?

They are literally pulled apart. After lining up in the middle with all the other chromosomes, spindle fibers separate the set of chromosomes.

• What would happen if the sister chromatids failed to separate?

If the chromatids failed to separate, then both cells would be rendered useless due to too much or too little DNA. In other words, nothing can go right.

• What events could promote genetic variation during mitosis?

If something happened wrong during the S stage, genetic variation is very possible. During the S stage, DNA is multiplied so it can go into two cells. If anything goes wrong here, the cells will have redundant DNA. Another possible flaw occurs in the splitting of cells. If the spindle fibers pull on the chromosomes wrong, then both daughter cells will be useless.

• What problems could occur with a loss of cell cycle control?

Genetic mutations seem very probable. Sadly, one of the possible side effects is cancer, which is very likely if something goes wrong.