1. Unit 7: Cellular Reproduction
PART 1: Sexual vs. Asexual Reproduction
Lessons 7.1 & 7.2

2. Unit 7 Table of Contents PART 1: Lesson 7.1 Asexual Reproduction
Lesson 7.2 Sexual Reproduction
PART 2:
Lesson 7.3 Chromosomes
Lesson 7.4 The Cell Cycle
Lesson 7.5 Mitosis
Lesson 7.6 Cancer
Lesson 7.7 Meiosis

3. Lesson 7.1 Asexual Reproduction Learning Objectives
I can define asexual reproduction and give examples.
I can describe the differences between sexual and asexual reproduction

4. 2 Types of Reproduction Asexual Reproduction Sexual Reproduction
involves only 1 parent
offspring genetically identical to parent
involves regular body cells
its quick
Sexual Reproduction
involves 2 parents
offspring genetic mix of both parents
involves specialized sex cells
its slow

5. Asexual Reproduction Asexual reproduction involves: One parent
No sex cells
Offspring produced by cell division
Offspring identical to parent (same DNA)
Several types in prokaryotes, plants and animals

6. Types of Asexual Reproduction
Binary fission
Budding
Vegetative reproduction
Cloning

7. 1. Asexual Reproduction: Binary Fission
One parent cell splits into two genetically identical cells
Prokaryotes only
Examples: bacteria, Ecoli, pond critters

8. 2. Asexual Reproduction: Budding
a new organism grows by cell division on the body of its parent
the bud, or offspring is identical to the parent
when it is large enough, the bud may break off and live on its own
Examples: Yeast, Hydra, cactus

9. 3. Vegetative Reproduction

10. 4. Asexual Reproduction: Cloning
DNA from one organism is used to create a second organism that is an identical copy of the original.
The copied material, which has the same genetic makeup as the original, is referred to as a clone.
All forms of asexual reproduction create clones.
Humans have successfully cloned various animals, starting with Dolly the sheep, but ethical laws have stopped scientists from attempting to clone humans. (But there are plenty of movies about it!)

12. Wishful Thinking!!!

13. Examples: Asexual Reproduction

14. Lesson 7.2 Sexual Reproduction Learning Objectives
I can define sexual reproduction and give examples.
I can describe the differences between sexual and asexual reproduction

15. Sexual Reproduction Sexual reproduction involves: 2 parents
Sex cells: sperm and egg
Sperm and egg join = fertilization
Offspring look different from parent (mixed DNA)
Sexual reproduction produces a greater chance of variation within a species than asexual reproduction would.
This variation improves the chances that a species will adapt to its environment and survive.

16. Types of Sexual Reproduction
Conjugation
Pollination
External Fertilization
Internal Fertilization

17. 1. Sexual Reproduction: Conjugation
Bacterial conjugation:
the transfer of genetic material between bacterial cells
by direct cell-to-cell contact or by a bridge-like connection between two cells.

18. 2. Sexual Reproduction: Pollination
Pollination occurs in plants.
Pollen is taken from the male parts of one plant and delivered to the female parts of another plant, usually by an insect.
The pollen then travels inside the flower and fertilizes an egg.
The egg will grow into a seed which can become a new plant.
Pollination also allows for genetic variation because the traits from two plants are mixed.

19. Pollination: Sexual Reproduction in Plants
Female Parts
Male Parts
(Pistil)
pollen (male) + ovule (female) → single-celled zygote → multi-celled embryo (contained in a seed) → new individual

20. 3. Sexual Reproduction: External Fertilization
The females lay the eggs in the water and the male squirts the sperm in the same area, usually in water.
The sperm then swims towards the egg cell.
External fertilization usually occur in fish and amphibians.

21. 4. Sexual Reproduction: Internal Fertilization
Fertilization occurs inside the female.
Internal fertilization occurs in mammals, insects, birds, reptiles.
Mammals (humans, gorillas, lions, elephants, rats, zebras, and dolphins have live births)
Insects, birds, reptiles lay eggs

22. Examples: Sexual Reproduction

23. Which is Better? It depends!
Asexual Reproduction
advantages
does not require special cells or a lot of energy
can produce offspring quickly
in a stable environment creates large, thriving population
disadvantages
limited ability to adapt
face massive die-off if environment changes
Sexual Reproduction
advantages
lots of variation within a species
able to live in a variety of environmental settings
able to adapt to changes in the environment
disadvantages
needs time & energy
produce small populations

24. Types of Reproduction: Sexual vs. Asexual
Take a look at the table below. It summarizes the important differences between sexual and asexual reproduction.
Sexual Reproduction
Asexual Reproduction
Number of Parents
2 parents
1 parent
Genetic Variation
Lots of genetic variation (a mix of traits from 2 parents)
No genetic variation (the same traits from only 1 parent)

25. Which Type of Reproduction Is This?
Activity:
Which Type of Reproduction Is This?

26. What type of reproduction is this??? Explain…

27. What type of reproduction is this??? Explain…

28. What type of reproduction is this??? Explain…

29. What type of reproduction is this??? Explain…

30. What type of reproduction is this??? Explain…

31. What type of reproduction is this??? Explain…

32. What type of reproduction is this??? Explain…

33. What type of reproduction is this??? Explain…

34. What type of reproduction is this??? Explain…

35. What type of reproduction is this??? Explain…

36. What type of reproduction is this??? Explain…

37. What type of reproduction is this??? Explain…

38. What type of reproduction is this??? Explain…