1. BIOLOGY NOTES GENETICS PART 2 PAGES 166-176

2. ____ Describe the process of meiosis, including independent assortment and crossing over. Explain how reduction division results in the formation of haploid gametes or spores ____ Compare and contrast mitosis and meiosis and relate them to the processes of sexual and asexual reproduction and their consequences for genetic variation
Standards
5.4
5.5

3. Essential Question: What are the advantages of sexual 1.
reproduction over asexual reproduction? 1.

4. Chromosome Number
The purpose of the cell ______ with ________ is to make daughter cells that are ________ to the parent cell.
This allows the organism to _____, develop and ______ cells
Species are ________ for the number of chromosomes they have
e.g.
cycle
mitosis
identical
grow
repair
specific
fruit fly = 8 chromosomes

5. the chromosome number has no ______ on the overall ___________ of an organism
e.g.
In a human ________ cell there are ___ different chromosomes
In a human ________ cell, the ___ chromosomes are grouped into __ sets of ___, one chromosome is donated by _____ and the other by _____
effect
complexity
ferns = 1200 chromosomes / cell
somatic 46
somatic 46 2 23
mom
dad

7. Homologous chromosomes = matching pairs of _____________
homologous chromosomes have similar ______ for the body but are not _________
DIAGRAM:
chromosomes
traits
identical

8. How is it possible for two different parents to form an offspring that has the same amount of chromosomes as they do?
A. Sexual reproduction = the process by which chromosomes of __ parents combine to form a new __________
Each parent has to produce _____ that have only ____ the amount of chromosomes as their _______ cells
gametes = special, reproductive cells that house only ___ the number of chromosomes as _____ cells
e.g. 2
individual
cells
1/2
parent
1/2
body
egg, sperm

10. with regard to chromosome number, gametes are described as being ________ while somatic cells are _________
haploid = term used to describe cells with only __ complete set of chromosomes
e.g.
diploid = term used to describe cells with ___ complete sets of chromosomes
haploid
diploid 1
egg, sperm (gametes) 2
body cells (somatic cells)

11. B. Fertilization = the process of an ____ and _______ combining to produce a new __________
Zygote = the single cell that results from ___________
zygotes are ________ when describing the number of chromosomes within the cell
egg
sperm
individual
fertilization
diploid

12. II. The Production of Gametes Since a new cell is being made when an _________ or _______ is formed, the cell ______ is used only instead of ________ there is a process called ________
offspring
zygote
mitosis
cycle
meiosis

13. A. Interphase
This include ___, __, and ___ phases which will _____ all the organelles that the new gametes will need as well as copying the ____
B. Meiosis = the process in which _____ are produced that have only ____ the number of chromosomes as _______ cells G2 G1 S
copy
DNA
cells
1/2
parent

14. Meiosis involves __ divisions after interphase which can cut the chromosome number by ____ for the daughter cells
Meiosis division 1 includes: __________, ____________, ___________, and ___________
Meiosis division 2 includes: ___________, ____________, ___________, and ____________ 2
1/2
prophase I
metaphase I
anaphase I
telophase I
prophase II
metaphase II
anaphase II
telophase II

19. C. Cytokinesis
divides the resulting __ daughter cells each of which is _______ in chromosome number 4
haploid

20. III. Gamete Formation
Even after the cell cycle with ________, the daughter cells are only ________ NOT fully mature ____ or sperm
Gametogenesis = the production of fully mature _________ or sex cells
the process to obtain a fully mature _________ will vary by organism in time and according to sex
meiosis
gametes
egg
gametes
gametes

21. A. Males- for the __ daughter cells that are produced, __ turn into sperm cells
DIAGRAM: 4 4

22. B. Females - for the __ daughter cells that are produced, only __ becomes an egg due to ________ division of cytoplasm
DIAGRAM: 4 1
unequal

23. IV. Mitosis vs. Meiosis Cycle Mitosis Meiosis diploid haploid somatic
Daughter Cells Chromosome Number
Product (Type of cell made)
Number of Divisions
Purpose
diploid
haploid
somatic
cells
gametes
1 / cycle
2 / cycle
to make /
replace cells
that are
identical
to make
cells with ½
chromosome
number