Meiosis (Part II) Follow-up to Meiosis/Meiosis v. Mitosis Lecture

CATALYST The CATALYST is to be done independently and silently. Answer the following questions in your notebook: TIME REMAINING: 8:00 MINUTES 1. What is meiosis? What is the product of meiosis? Is meiosis an example of sexual or asexual reproduction? How is meiosis different from mitosis?

CATALYST The CATALYST is to be done independently and silently. Answer the following questions in your notebook: TIME REMAINING: 7:00 MINUTES 1. What is meiosis? What is the product of meiosis? Is meiosis an example of sexual or asexual reproduction? How is meiosis different from mitosis?

CATALYST The CATALYST is to be done independently and silently. Answer the following questions in your notebook: TIME REMAINING: 6:00 MINUTES 1. What is meiosis? What is the product of meiosis? Is meiosis an example of sexual or asexual reproduction? How is meiosis different from mitosis?

CATALYST The CATALYST is to be done independently and silently. Answer the following questions in your notebook: TIME REMAINING: 5:00 MINUTES 1. What is meiosis? What is the product of meiosis? Is meiosis an example of sexual or asexual reproduction? How is meiosis different from mitosis?

CATALYST The CATALYST is to be done independently and silently. Answer the following questions in your notebook: TIME REMAINING: 4:00 MINUTES 1. What is meiosis? What is the product of meiosis? Is meiosis an example of sexual or asexual reproduction? How is meiosis different from mitosis?

CATALYST The CATALYST is to be done independently and silently. Answer the following questions in your notebook: TIME REMAINING: 3:00 MINUTES 1. What is meiosis? What is the product of meiosis? Is meiosis an example of sexual or asexual reproduction? How is meiosis different from mitosis?

CATALYST The CATALYST is to be done independently and silently. Answer the following questions in your notebook: TIME REMAINING: 2:00 MINUTES 1. What is meiosis? What is the product of meiosis? Is meiosis an example of sexual or asexual reproduction? How is meiosis different from mitosis?

CATALYST The CATALYST is to be done independently and silently. Answer the following questions in your notebook: TIME REMAINING: 1:00 MINUTES 1. What is meiosis? What is the product of meiosis? Is meiosis an example of sexual or asexual reproduction? How is meiosis different from mitosis?

CATALYST Silently and on your own, complete the task below 2. During mitosis, two cells are produced from the original cell. How does the number of chromosomes in each new cell compare with the number in the original cell? A. Twice the number B. The same number C. One-half the number D. One-quarter the number 3. Which of the following is NOT made through meiosis? A. an egg cell B. a gamete C. a sperm cell D. a skin cell TIME REMAINING: 2:00 MINUTES

CATALYST TIME REMAINING: 1:00 MINUTES Silently and on your own, complete the task below During mitosis, two cells are produced from the original cell. How does the number of chromosomes in each new cell compare with the number in the original cell? Twice the number The same number One-half the number One-quarter the number Which of the following is NOT made through meiosis? an egg cell a gamete a sperm cell a skin cell

CATALYST The CATALYST is to be done independently and silently. Answer the following questions in your notebook: 1. What is meiosis? What is the product of meiosis? Is meiosis an example of sexual or asexual reproduction? How is meiosis different from mitosis?

Silently and on your own, complete the task below During mitosis, two cells are produced from the original cell. How does the number of chromosomes in each new cell compare with the number in the original cell? Twice the number The same number One-half the number One-quarter the number Which of the following is NOT made through meiosis? an egg cell a gamete a sperm cell a skin cell CATALYST

Key Vocab Mitosis Meiosis Diploid Haploid Fertilization Sexual Reproduction Asexual Reproduction Variation Stability Random Assortment Crossing Over Mutation Nondisjunction

Variation

Variation Variation: differences between individuals

Variation (notes) Variation is good If everyone had the same genes, 1 disease could kill everybody

Red Queen Hypothesis “Running” (evolving) to stay in the same place Reducing the risk of infection in offspring (selection pressure for sexual reproduction) SN

When people have different genes (variation), only a few could be killed by a disease Variation comes from sexual reproduction (reproduction with 2 parents) Variation (notes)

Sources of Variation People have variation because we have different genes. The sources of variation are how we get different genes

1. Sexual reproduction (fertilization) leads to variation because genes are inherited from 2 parents Sources of Variation

2. Random assortment: chromosomes split into gametes randomly. This is why you inherit traits by chance. Just because you have your Dad’s nose doesn’t mean you have his eyes. gamete 1 gamete 2 gamete 3 gamete 4 Sources of Variation

3. Crossing over: chromosomes cross over each other so we don’t inherit 1 entire chromosome from just 1 parent Sources of Variation

4. Mutation: the cell makes a mistake in DNA Sources of Variation Sickle Cell Anemia

5. Nondisjunction: when the chromosomes don’t separate in meiosis Nondisjunction leads to the wrong number of chromosomes Leads to Down Syndrome Sources of Variation

EXIT TICKET What is variation? Is variation good or bad? Why or why not? What is sexual reproduction? Is it a source of variation? What is the difference between a nondisjunction and a mutation? What is the importance of the relationship between meiosis and variation?