1. Date: February 28th, 2017
Aim # 53: How do organisms create offspring through sexual reproduction? ?
HW:
Daily Review of Class Notes
Worksheet- Diploid vs. Haploid
Quiz Thursday- Mitosis/Meiosis
Do Now: Use your notes to create a Venn diagram to compare and contrast sexual and asexual reproduction.

2. Asexual vs. Sexual Reproduction
1 Parent
Produce
Offspring
2 Parents
Offspring are
identical
Critical for survival
of the species
Offspring are
not identical
Bacteria, Amoeba,
Body Cells
Humans,
Dogs, Plants
Asexual Reproduction
Sexual Reproduction

3. Aim #53: How do organisms create offspring through sexual reproduction?

4. What is Sexual Reproduction?
It involves the joining of two cells to begin the
development of a new individual.
These special cells are called: Sex Cells (Gametes)

5. What are the names of these sex cells?
Egg cell
(Female)
Sperm Cell
(Male)
The joining of a sperm cell with
an egg cell is called fertilization.

6. 1) How many chromosomes do we have in our cells?
We have 46 chromosomes
in each our body cells.
We can also say that we
have 23 pairs of
chromosomes
Karyotype

7. 2) Why do we have 2 of each chromosome?
We get one chromosome from each parent
3) Each pair of chromosomes are called:
Homologous Chromosomes

8. 4) Homologous Chromosomes:
Mom
Dad
Gene
Eye Color B G
Part of a
chromosome
that codes for
a trait B R
Hair Color
Have genes that code for the same trait, but may
have different versions of that trait

9. 5) How are chromatids different than homologous chromosomes?
Chromatids are exact
duplicates of each other
Homologous chromosomes
have genes that code for
the same trait, but they may
code for different versions
of that trait

10. 6) How many chromosomes do the offspring have after mitosis?
46X
Mitosis
46X
46X

11. 7) Do our sex cells have 46 chromosomes?
NO!

12. 8) What would happen if our sex cells did have 46 chromosomes?92 +
Offspring
Egg
Sperm
The offspring would have 92 chromosomes

13. 9) Sexual Reproduction:23 23 46 +
Offspring
Egg
A fertilized egg cell is called a Zygote
Sperm
10) Characteristics of Sexual Reproduction: 2
1) Is the creation of a new individual from parents.
2) Offspring are not genetically to the parents.
identical

14. 11) Sex Cells (Gametes) Sex Cells: SPERM and EGG
Sex cells should have 1/2 the normal number of chromosomes

15. 12) Chromosome Number
Diploid cells: (2n) normal number of chromosomes (Body Cells)
Haploid cells: (n) ½ the normal number of chromosomes (Sex Cells)

16. Haploid Cells and Fertilization
Diploid vs Haploid
Haploid Cells and Fertilization
Diploid Cells

17. Date: March 1st, period 1
Aim # 53: How do organisms create offspring through sexual reproduction?
HW:
Daily Review of Class Notes
Worksheet- Diploid and Haploid
Quiz Friday- Mitosis/Meiosis
Do Now: Please take out last night’s homework.

18. 13) Meiosis
The process by which haploid (sex) cells are produced with half the number of chromosomes.

19. 14) What is the end result of meiosis?
46X
Meiosis
23X
23X
23X
23X

20. 15) Where does meiosis occur?
Gonads – Ovaries and Testis

21. 16) Why is meiosis important?
Maintains the number of chromosomes from generation to generation
Provides genetic variation
Only during fertilization (union of sperm and egg) is the full (diploid) set of chromosomes restored.

22. Practice Problems: