Meiosis (Part II)
Follow-up to Meiosis/Meiosis v. Mitosis Lecture
CATALYST
he CATALYST is to be done independently and silently.
nswer 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
he CATALYST is to be done independently and silently.
nswer 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
he CATALYST is to be done independently and silently.
nswer 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
he CATALYST is to be done independently and silently.
nswer 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
he CATALYST is to be done independently and silently.
nswer 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
he CATALYST is to be done independently and silently.
nswer 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
he CATALYST is to be done independently and silently.
nswer 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
he CATALYST is to be done independently and silently.
nswer 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.
3.
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
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
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
TIME REMAINING:
1:00 MINUTES
CATALYST
he CATALYST is to be done independently and silently.
nswer 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?
CATALYST
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
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
SN
Red Queen
Hypothesis
•
•
“Running” (evolving) to
stay in the same place
Reducing the risk of
infection in offspring
•
(selection pressure for
sexual reproduction)
Variation (notes)
• When people have different genes
(variation), only a few could be killed by
a disease
• Variation comes from sexual reproduction
(reproduction with 2 parents)
Sources of Variation
People have variation because we have
different genes. The sources of
variation are how we get different
genes
Sources of Variation
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
Sickle Cell Anemia
Sources of Variation
5. Nondisjunction: when the chromosomes
don’t separate in meiosis
Nondisjunction leads to the wrong number of
chromosomes
Leads to Down Syndrome
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?