Genetics and Heredity

Genetics and Heredity • Heredity • The passing of ______from parent to offspring. • 1. Genes on chromosomes control the ______that show up in an organism • 2. The different forms of a trait that a gene may have are ______• 3. During ______a pair of chromosomes separates and the ______move into separate cells • 4. Each chromosome now contains ______gene for each trait. • 5. The study of how traits are inherited is ______B. Gregor Mendel • Known as the ______– Austrian monk – Studied mathematics and science – Began experimenting with ______in 1856

• 1. Mendel was the first to use the ______to explain heredity and to trace one trait for ______Hybrid • 2. A hybrid receives ______genetic information for a trait from each parent – a. ______allele- covers up or dominates the other trait – b. ______allele- trait that seems to disappear Probability • 3. Probability helps you ______that chance that something will happen Punnett Square • 4. A ______can help you predict what an offspring will look like – a. ______stand for dominant alleles – b. ______stand for recessive alleles

Genotype • 5. Genotype is the ______of an organism

• a. ______- an organism with two alleles for one trait that are the same (Ex. Written TT, or tt) – Mendel would have called it ______• b. ______- an organism with two alleles for one trait that are different (ex. Written Tt) – Mendel would have called it ______Phenotype • 6. Phenotype – the way an organism ______as a result of its genotype.

Punnett Practice • This animated punnett square shows a cross between a homozygous brown eyed father (BB) and a homozygous blue-eyed mother (bb) *All of the children will be ______for Brown eyes (______)

Punnett Practice The orange bird has two ______A genes. •We put two A s along the top of the square.

The blue bird has two ______a genes. • We put two a s down along the left side of the square.

All the offspring have the genes Aa. They will all have orange feathers, but will carry a recessive gene for blue feathers. This is called the ______Punnett Practice • Now suppose that two individuals from the F1 generation become parents.

• Here they are! The baby birds are called the F2 generation. • You can see how their genes work out.-- • One bird will be ______with two AA genes.

• Two birds will be ______with genes coded Aa.

• One bird will be ______and will have two recessive aa genes.

Individual nests of birds may not turn out exactly like this, but if there are many baby birds, they will work out genetically with the ______. Suppose you crossed a heterozygous yellow pea plant (Yy) with a homozygous green pea plant (yy) What are the possible genotypes and phenotypes of the offspring? Make a punnett square to find out 1) Which square is correct? 2) What are the correct genotypes and phenotypes?