My teacher is teaching us about Punnet Squares. But I don't quite understand how to do it? I have a test before christmas break. I know I need 2 be smart in 7th grade, but I don't know everything. Can u help me Jiskha? I don't want 2 fail science.
These sites should help you.
http://www.youtube.com/watch?v=Y1PCwxUDTl8
http://www.khanacademy.org/science/biology/heredity-and-genetics/v/punnett-square-fun
http://anthro.palomar.edu/mendel/mendel_2.htm
u have 2 make a cool rhyme.if u like rap then rap it.Trust me i learned that in 6th grade.Its really easy.
Of course, I can help you understand Punnett squares! They are a helpful tool used in genetics to predict the possible outcomes of offspring based on the genetic makeup of their parents. Here's how you can do it step by step:
1. Understand the basics: Before diving into Punnett squares, it's important to have a basic understanding of genetics concepts such as alleles, dominant and recessive traits, and genotypes (the genetic makeup of an individual).
2. Identify the traits: Determine the specific traits you need to study. For example, if you're studying the inheritance of eye color, you might consider traits like brown eyes (dominant) and blue eyes (recessive).
3. Determine the parent's genotypes: Assign letters to represent the alleles for each trait. For instance, you could use "B" for brown eyes and "b" for blue eyes. Determine the genotypes of the parents by using uppercase letters for dominant traits and lowercase letters for recessive traits. For example, if both parents have brown eyes, their genotypes would be "BB" since brown eyes are dominant.
4. Create the Punnett square: Draw a square and divide it into four equal boxes. On the top row of the square, write one of the mother's alleles (B) above each box. On the left column, write one of the father's alleles (B) next to each box.
5. Fill in the boxes: Combine the alleles from the corresponding row and column. For example, in the first box, the combination would be "BB" since both parents have the allele "B." Repeat this process for each box.
6. Determine the offspring's genotypes: Analyze the combinations in each box to determine the offspring's genotypes. If the letters in a box are different like "Bb," the offspring is heterozygous (carrying both dominant and recessive alleles). If the letters are the same like "BB" or "bb," the offspring is homozygous (carrying two copies of the same allele).
7. Determine the offspring's phenotypes: Use a key to determine the phenotypes based on the genotypes. For example, if brown eyes are dominant (B) and blue eyes are recessive (b), the offspring with the genotype "Bb" would have brown eyes.
Remember to practice with different traits and genotypes to become more comfortable with Punnett squares. This will help you better understand how the traits are inherited and predict possible outcomes. Good luck with your test!