Sciencio weeko.......[:{)-I-(

This week in science we learned about how traits of people work. For example, if a pea is yellow, and the other pea that it is breeding with is yellow, then the children are likely to be yellow if they are both homozygous. This means that the alleles are both dominant. Alleles are traits that can not be seen. A genotype is a set of alleles. A phenotype is a trait that you can see such as brown eyes. For example, brown eyes are more dominant than blue eyes in my family. This means that most of my family members have brown eyes. To figure these problems out, you can use something called punit squares. Punit squares match up alleles to see different traits of people families. For example, if brown eyes are more dominant than blue, Brown would be BB as there alleles. Blue would be bb. These are homozygous, meaning the same alleles. If brown was heterozygous, the alleles would be Bb. They are still brown though because whenever there is one dominant allele in the genotype, it will be the more dominant trait. The only time you will get the recessive trait is when there are two recessive alleles such as bb.

BB-Dominant trait- homozygous
Bb-Dominant trait- heterozygous
bb-recessive trait-homozygous

If your dominant trait is blond hair, and recessive trait is brown hair
And alleles are BB and bb
The four off springs would all be Bb
There for all of the off springs would have Blond hair because there is a dominant trait in all four of the genotypes

sCiEnCe ClAsS

This week we learned about meiosis. Meiosis is sexual reproduction. It is where sex cells are made. The chromosomes go through DNA replication and then split into two new cells. They are now haploid cells because they have 50% of the DNA. It started out with diploid, when it had 100% of the cells. After the chromosomes split, they split again into four sperm cells. We also learned about homologous pairs. These are two of the same pairs of chromatids. In meiosis, the chromosomes have to switch parts of theselves do replicate. Unlike mitosis, the chromosomes are lined up on either side of a plate in the cell. Then they are pulled apart by the spindle fibers.
Another difference between mitosis and miosis is that meiosis has double the stages. For example, there is a prophase1 and prophase2. This is because they make two cells and then they make four. When they replicate for the first time, it is the first stage. The second replication is the second stage.