There will be a test on Monday over Punnett squares and related information. This will be a multiple choice test, different from the practice problems we have already done. Here is a list of things to be sure you know in order to do well on the test.
Genotype is what we call the code for the genes. We use letters to show the dominant and recessive versions of a gene (BB, Tt, rr). Capital letters show the dominant version of the gene (B) while small letters show the recessive version of the gene (b). The dominant version will mask the recessive version so if a living thing has Bb, it will have the dominant trait because the B masks the b. For example, in pea plants, Purple flowers are dominant over white. So pea plant that is FF will be purple. So will a Ff. But plant with ff will be white because it has only the recessive versions of the gene.
If the two version are both dominant (BB) or both recessive (rr) it is purebred for that trait. Remember pure . . . they are both the same or pure. If the two version are one dominant and one recessive (Bb), it is called hybrid. You need to know these terms so you can figure out the genotype when a practice problem uses these words. For example, if the problem says that it is a purebred white sheep and white is dominant, then the genotype will be BB.
Be sure you know how to do a Punnett square. A Punnett square is used to predict the number of offspring that will have a particular trait. The link below shows how Punnett squares work and has examples. (Note: I will not use the words heterozygous (means hybrid) or homozygous (means purebred) on the test. You are also welcome to come see me at lunch for a lesson on Punnett squares.
This link is a practice quiz for Punnett squares.