UNIT 5: Gene Expression and Inheritance
5B: Sexual Reproduction and
Meiotic Cell Division
Roadmap for the year:
Themes for the year:
Unit 1: Interconnectedness of Life
Unit 2: Ecological Biochemistry
Unit 3: Cellular Biology: Structure Leads to Function
Unit 4: DNA Structure and Cellular Reproduction
Unit 5: Gene Expression and Inheritance
 5A- Gene Expression
 5B- Sexual Reproduction and Meiotic Cell
Division
 5C- Genetic Inheritance
Unit 6: Evolution and Classification of Living Things
Unit 7: Biotechnology, Human Biology, and Disease
How does this unit
contribute to your
understanding of the
following themes?
The Big Picture…
 Life on Earth has
various Levels of
Organization
 The Structure of
Living Things leads
to their Function
 In sexually reproducing organisms, chromosomes occur in pairs (one from
each parent).
 Meiotic cell division is used by sexually reproducing organisms to produce
genetically unique haploid gametes.
 Meiotic cell division and sexual reproduction leads to genetic variability.
 Why do some organisms look similar to family members and some look so
different?
Suggested Resources…
Homework Assignments
Classwork Assignments
Laboratory Activities
Formative Assessments
Diagrams/Images of the processes of Meiosis
Online Textbook
Review Asexual Reproduction - Mitosis
By the conclusion of this unit, you should
know the following:
Meiosis occurs in sexually reproducing
organisms in two discrete phases
(Meiosis I and Meiosis II), culminating in
the creation of genetically unique haploid
gametes.
Meiosis is often called ‘reduction
division’. During meiosis I a diploid
number of double-armed chromosomes is
reduced to a haploid number of doublearmed chromosomes. During meiosis II
that is then reduced to a haploid number
of single-armed chromosomes.
Crossing over, independent assortment &
random fertilization of unique gametes all
contribute to variability within a species.
In sexually reproducing organisms,
diploid parents produce haploid gametes
(through meiotic cell division) which
then restore the diploid number upon
fertilization; the new diploid organism
then grows by mitotic cell division.
Spermatogenesis occurs in male testes to
create 4 functional sperm cell per meiotic
cycle.
Oogenesis occurs in female ovaries to
create 1 functional egg cell (and 3 polar
bodies) per meiotic cycle.
Nondisjunction is one example of an
error that can occur during meiosis
wherein chromosomes do not divide
properly, resulting in the creation of
abnormal gametes.
Fertilization using abnormal gamete(s)
generally leads to abnormal or nonviable
zygotes.
A karyotype is a picture formed by
arranging homologous chromosomes
according to their size; this chart can be
used to check for chromosomal
abnormalities.
By the conclusion of this unit, you should
be able to do the following:
Compare and contrast the effect of
mutations in somatic cells vs. sex
cells.
Compare and contrast sexual and
asexual reproduction.
Apply the understanding of normal
meiosis to problems that may occur
during gamete formation.
Realize that there are three main
processes (crossing over, independent
assortment, and random fertilization
of unique gametes) that contribute to
genetic variability of a sexually
reproducing species.
Compare and contrast mitosis,
meiosis I and meiosis II.
Justify the name, ‘reduction division’
for meiosis by explaining how
haploid gametes are created from a
diploid parental body cell.
Explain how meiotic and mitotic cell
division are both necessary to give
rise to successive generations of
sexually reproducing organisms.
Compare and contrast
spermatogenesis and oogenesis.
Explain what a karyotype is and how
it is generated.
Recognize the presence and possible
origin of chromosomal abnormalities
in a human karyotype.
Sexual Reproduction and Meiotic Cell Division Vocabulary
Words Found in the Glossary
1) Centromere:
2) Diploid:
3) Haploid:
4) Gamete:
5) Zygote:
6) Asexual Reproduction:
7) Sexual Reproduction:
8) Homologous (Chromosomes):
9) Karyotype:
10) Mitosis:
11) Meiosis:
12) Fertilization:
13) Interphase:
14) Prophase:
15) Metaphase:
16) Anaphase:
17) Telophase:
18) Cytokinesis:
19) Crossing-over:
20) Independent Assortment:
21) Nondisjunction:
Words NOT Found in the Glossary (but may be within the textbook)
22) Double Arm Chromosome:
23) Single Arm Chromosome:
24) Somatic Cell:
25) Egg:
26) Sperm:
27) Reduction Division:
28) Gametogenesis:
29) Oogenesis: