Learning goal: Assess their understanding of meiosis,
genetics, evolution and population ecology
Page 17
Thursday January 15, 2015
Collect meiosis problems.
Warm up: At what stage in meiosis does crossing over occur? Are the cells
considered gametes (sex cells) during crossing over?
Crossing occurs during prophase I and no, the cells are not gametes because they are
still Diploid (2n) cells during meiosis I.
Prophase I
Crossing over adds genetic variation (page 7 in your notebook)
Quiz 22 (tomorrow) will cover content from last week.
4
Genetic
variation and
assortment
Evolution and
reproduction
3
Events of
meiosis,
variation and
reproduction
2
Steps of
meiosis basic
definitions
1
Mitosis vs
meiosis,
sexual vs
asexual
Learning goal: Assess their understanding of meiosis,
genetics, evolution and population ecology
Page 17
Thursday January 15, 2015
Learning goal: Assess their understanding of meiosis, genetics, evolution and
population ecology
Learning scale:
1
2
3
4
Differentiate
between
mitosis and
meiosis, sexual
and asexual
reproduction.
Define
spermatogenesis
and oogenesis. List
the steps to
meiosis.
Define sexual and
asexual
reproduction.
Summarize the events
the occur during
meiosis. Differentiate
between sexual and
asexual reproduction
and the correlation of
genetic variation.
Explain how genetic
variation is a function of
crossing-over and
independent assortment
during spermatogenesis and
oogenesis. Evaluate the
genetic and evolutionary
advantages to sexual versus
asexual reproduction.
Student’s self-evaluation: Complete at home or at the end of class, use the
4-3-2-1 Learning scale (two to three sentences).
Homework: Complete lab questions.
4
Genetic
variation and
assortment
Evolution and
reproduction
3
Events of
meiosis,
variation and
reproduction
2
Steps of
meiosis basic
definitions
1
Mitosis vs
meiosis,
sexual vs
asexual
Learning goal: Assess their understanding of meiosis,
genetics, evolution and population ecology
Page 17
Thursday January 15, 2015
Meiosis lab answers
Are these chromosomes homologous? Yes
Explain your response using the alleles on chromosome #1. The chromosomes are of similar size
and shape and have the same alleles (S or s)
During “S” of interphase the DNA is replicated.
How many pairs of homologous chromosomes are there? 4
Is there only 1 way the homologous chromosomes can line up? Yes
How may possibilities will this organism have? 24 = 16
Are these cells diploid or haploid? Haploid
Can crossing over happen at this point? No Explain: The chromosomes only cross over with
identical chromatids. This would not lead to genetic diversity.
What are these reproductive cells called? Gametes
Are these cells haploid or diploid? Haploid Explain: The cells have half the number of chromosomes
as the original cells. They have an “n” in stead of “2n” number of chromosomes.
Explain how crossing over played a role in making the gametes genetically different from mom and
dad? Crossing over mixes the genetic information on the homologous chromosomes.
Explain how independent assortment played a role in making the gametes genetically different from
mom and dad. Independent assortment randomly distribute genetic information to gametes.
Explain how random fertilization also leads to even more genetic variation. Random fertilization
allows for any combination of gametes to meet.
Why must a gamete fuse with another gamete? Each gamete only contains half the genetic
information required to create a new individual.
4
Genetic
variation and
assortment
Evolution and
reproduction
3
Events of
meiosis,
variation and
reproduction
2
Steps of
meiosis basic
definitions
1
Mitosis vs
meiosis,
sexual vs
asexual
Learning goal: Assess their understanding of meiosis,
genetics, evolution and population ecology
Page 18
Thursday January 15, 2015
Complete the worksheet “Week 22 Application” using notes and the textbook.
**Please fix the header
4
Genetic
variation and
assortment
Evolution and
reproduction
3
Events of
meiosis,
variation and
reproduction
2
Steps of
meiosis basic
definitions
1
Mitosis vs
meiosis,
sexual vs
asexual