Today we learned about genetics. We learned how genes are used to express a physical trait, which can either be dominant or recessive. There are two types of cells: a sex cell called a gamete, which is a sperm and an egg, and a somatic, which is a body cell. The two go through totally different processes to get to their chromosome. Gametes go through meiosis, where only 1 set of chromosomes is produced. Somatic go through mitosis, where an exact copy of the cell is produced.
We also learned how to solve genetics problems. Here are the steps:
- Write down the info. For example, Dominant=A=trait.
- Parenting genotype. Aa x Aa.
- Law of segregation. For example, Aa splits up into A and a.
- Punnett square. See example on the left.
- Fill in the square. Below the empty is one that is filled in.
- Create your ratios. For example, on the right, the phenotype ratio is 3 dominant :1recessive. The genotype ratio would be 1AA:2Aa:1aa.
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