Onion Cell Mitosis Web Lab Question: What phase of mitosis does a cell spend most of its life in? How can we figure it out? Web lab – Due ________________

Basic Genetics You, like most animals, are __________. During reproduction, ______________ _____________from two parents combine to make a new __________ organism. Thus, only ______ of an organism’s genetic information is passed on to its offspring

Meiosis ________ is cell division that makes haploid gametes. The chromosome number is reduced by ________. Only 1 of each ______________ ______of chromosomes gets passed on to the offspring.

Genes, Alleles, and Traits A trait is a ________________. For example, brown eye color is a trait most humans have. A gene is a part of a chromosome that carries ___________________________________. For example, humans have one major eye color gene. An allele is a ________________________. In humans, the most common eye color alleles are brown and blue.

Follow the alleles The 2 chromosomes shown are a homologous pair. The chromosomes carry different genes. What % of the haploid cells have the red allele? ___ What % have the blue allele? ____

Probability Since there is an equal chance of each chromosome ending up in an offspring, it’s similar to _____________________

Genetics: The Study of Biological Heredity Do Now: If you flip a coin twice, what is the probability it will come up heads twice? What is the probability it will come up heads once and tails once? What is the probability it will come up tails twice?

Make A Prediction Please Write: If the two pea plants shown were crossed (mated), what % of the offspring do you predict will be purple? Why?

Anyone Predict 100% Purple? The first plant was ___________________for purple flowers – meaning when it was ____________________ all of the offspring had purple flowers. The second plant was pure breeding for white flowers. Which flower color would you describe as _______________in pea plants?______

Gregor Mendel Monk from Austria Studied statistics at the University of Vienna Garden enthusiast High school teacher The importance of his discoveries was only understood and appreciated years after his death Mendel “Father of Genetics”

Mendel’s Experiments Make another prediction: –If two of the offspring from the first cross (the ones that were all purple), what % of the offspring would be purple? Why?

A Word About Plants (Angiosperms = flowering plants)

Back to the Genetics Approximatly ______ of the offspring will have purple flowers. Mendel’s study of probability and statistics led him to hypothesize that each plant had two “factors” controlling flower color, one from each parent. How did he know???

Probability If you flip a coin, what is the probability it will come up heads?______ What is that probability expressed as a decimal?_______ If something has a probability of 1.0 will it happen?_______ You just flipped a coin 4 times and it came up tails all 4 tries. What is the probability it will come up tails if you flip it again?________ If you flip a coin twice, what is the probability it will come up heads both times?________

Classical Genetics is Based on Probability! You have ____ copies of each gene, but only one copy or the other is passed on to your offspring. Which copy of the gene that gets passed on is random. This is exactly what was happening in the pea plants – see if you can come up with an explaination tonight!

Homework Read 9-1 pp SR #1 p. 169