1. Cell Division and Meiosis
Sexual Reproduction
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Chapter Menu

2. Why do living things reproduce?
Chapter Introduction

3. Cell Division Prokaryote cells Fission Asexual Reproduction
Eukaryote cells
Mitosis
Growth
Repair
Meiosis
Sexual Reproduction
Chapter Introduction

4. Sexual Reproduction and Meiosis
What is sexual reproduction, and why is it beneficial?
What is the order of the phases of meiosis, and what happens during each phase?
Why is meiosis important?
Lesson 1 Reading Guide

5. Lesson 1 Reading Guide - Vocab
Sexual Reproduction and Meiosis
sexual reproduction
egg
sperm
fertilization
zygote
diploid
homologous chromosomes
haploid
meiosis
Lesson 1 Reading Guide - Vocab

6. What is sexual reproduction?
Sexual reproduction is a type of reproduction in which sex cells (often from two different parents) fuse to form an offspring.
Sexual reproduction
Fuse
Lesson 1

7. What is sexual reproduction?
Most cells are body cells, only a few are sex cells.
The ovary produces female sex cells called eggs.
The testis produces male sex cells called sperm.
Organism
Body Cells
Mitosis
Daughter Cells
Sex Cells
Meiosis
Egg Cells
Sperm Cells
Lesson 1

8. What is sexual reproduction? (cont.)
The egg and sperm combine during fertilization to create a zygote.
Lesson 1

9. Chromosomes The cell’s DNA is packaged in fixed sets of chromosomes.
Humans have 46 sets chromosomes.
Lesson 1

10. Lesson 1

11. Diploid Cells
Body cells are diploid because they have the complete set of homologous chromosomes.
Each chromosome is inherited from one parent, they have the same genes but can have different traits.
Diploid
Homologous
Genes
Traits
Mom
Dad
Lesson 1

12. Haploid Cells
Sex cells are haploid because they only have half the chromosomes from either mom or dad.
Sex cells are produced in meiosis where one diploid cell divides two times to make four haploid sex cells.
Haploid
Meiosis 2 4
1 Cell Diploid
4 Cells Haploid
Meiosis
Lesson 1

13. Haploid Cells Meiosis has two rounds of division. Meiosis I Meiosis II2 4
Meiosis II
Lesson 1

14. The Phases of Meiosis I
There are four phases of meiosis I.
Lesson 1

15. The Phases of Meiosis II
There are four phases of meiosis II.
Lesson 1

16. Why is meiosis important? (cont.)
After fertilization, haploid sex cells combine to produce a diploid zygote.
Egg
Sperm 23 46
Meiosis
Fertilization
Zygote
Mitosis
Lesson 1

17. Why is meiosis important?
Meiosis forms sex cells with the correct haploid number of chromosomes so that fertilization forms a diploid zygote.
Meiosis creates genetic variation.
Correct
Lesson 1

18. Why is meiosis important? (cont.)
Lesson 1

19. Genetic content compared to parent cell
Different
Identical
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20. Advantages of Sexual Reproduction
Sexual reproduction allows genetic variation that might produce traits that benefit an organism or population.
Sexual reproduction allows for the selection of desirable traits.
Genetic variation
Selection
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21. Advantages of Sexual Reproduction (cont.)
Why is sexual reproduction beneficial?
Lesson 1

22. Disadvantages of Sexual Reproduction
Organisms have to grow until they are mature enough to produce sex cells.
Organisms must search or wait for a mate.
Lesson 1

23. Fertilization occurs when an egg cell and a sperm cell join together.
Lesson 1

24. Organisms produce sex cells through meiosis.
Lesson 1

25. Sexual reproduction results in genetic variation among individuals.
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Lesson 1

26. Cells that have pairs of chromosomes are called ____.
A. chromosomes
B. body cells
C. diploid cells
D. sex cells
Lesson 1

27. During which process does one diploid cell divide and make four haploid sex cells?
A. osmosis
B. fertilization
C. reproduction
D. meiosis
Lesson 1

28. A. prophase I C. anaphase II B. metaphase I D. anaphase I
During which phase of meiosis I do chromosome pairs separate and pull to opposite ends of the cell?
A. prophase I C. anaphase II
B. metaphase I D. anaphase I
Lesson 1

29. Which type of cells have only one chromosome from each pair of chromosomes?
A. haploid cells
B. diploid cells
C. homologous cells
D. zygotes
Chapter Review - MC

30. Which type of reproduction occurs when the genetic materials from two different cells combine to produce offspring?
A. asexual C. sexual
B. animal D. zygote
Chapter Review - MC

31. What is the name of the new cell formed through fertilization during sexual reproduction?
A. an egg
B. a sperm
C. a chromosome
D. a zygote
Chapter Review - MC

32. In which of these organs is a female organism’s egg produced?
A. ovaries
B. homologous chromosomes
C. testes
D. haploid cells
Chapter Review - MC

33. A. telophase II C. prophase I B. metaphase II D. telophase I
Which of these is the final phase of meiosis in which a nuclear membrane forms around each set of chromatids?
A. telophase II C. prophase I
B. metaphase II D. telophase I
Chapter Review - MC