U7 L3 Sexual & Asexual Reproduction

ScienceFusion PowerNotes Grade 8
Sexual & Asexual Reproduction

1. Unit 7 Lesson 3 Sexual and Asexual Reproduction

Copyright © Houghton Mifflin Harcourt Publishing Company

2. Unit 7 Lesson 3 Sexual and Asexual Reproduction
Indiana Standards
Copyright © Houghton Mifflin Harcourt Publishing Company
•8.3.1 Explain that reproduction is essential for the
continuation of every species and is the
mechanism by which all organisms transmit
genetic information.
•8.3.2 Compare and contrast the transmission of
genetic information in sexual and asexual
reproduction.
•8.3.3 Explain that genetic information is
transmitted from parents to offspring mostly by
chromosomes.

3. One Becomes Two
Copyright © Houghton Mifflin Harcourt Publishing Company
What is asexual reproduction?
•Reproduction involves various kinds of cell
division.
•Most single-celled organisms and some
multicellular organisms reproduce asexually.
•In asexual reproduction, one organism
produces one or more new organisms that are
identical to itself.
Unit 7 Lesson 3 Sexual and Asexual Reproduction

4. What is asexual reproduction?
•The organism that produces the new organism or
organisms is called a parent.
•Each new organism is called an offspring.
•The offspring produced by asexual reproduction
are genetically identical to their parents.
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 7 Lesson 3 Sexual and Asexual Reproduction

5. How do organisms reproduce
asexually?
•Organisms reproduce asexually in many ways.
•Prokaryotes, including bacteria, reproduce
asexually by cell division.
•Some eukaryotes, including many multicellular
organisms, reproduce asexually by more complex
processes—types of cell division called mitosis.
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 7 Lesson 3 Sexual and Asexual Reproduction

6. How do organisms reproduce
asexually?
•Binary fission is the form of asexual reproduction
in prokaryotes.
•Budding occurs when a bud grows on a full-sized
organism.
•Budding is the result of mitosis.
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 7 Lesson 3 Sexual and Asexual Reproduction

7. How do organisms reproduce
asexually?
•A spore is a specialized cell that can survive harsh
conditions.
•Spores are light and can be carried by the wind.
•Some plants can reproduce asexually by
vegetative reproduction
•Vegetative reproduction happens through mitosis.
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 7 Lesson 3 Sexual and Asexual Reproduction

8. Two Make One
Copyright © Houghton Mifflin Harcourt Publishing Company
What is sexual reproduction?
•Most multicellular organisms can reproduce
sexually.
•In sexual reproduction, two parents each
contribute a sex cell to the new organism.
•Half the genes in the offspring come from each
parent.
Unit 7 Lesson 3 Sexual and Asexual Reproduction

9. What is sexual reproduction?
•Males produce sex cells called sperm cells.
•Females produce sex cells called eggs.
•Sex cells are produced by meiosis.
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 7 Lesson 3 Sexual and Asexual Reproduction

10. What is sexual reproduction?
•Sex cells have half of the set of genetic material
found in body cells.
•A sperm and an egg join together in a process
called fertilization.
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 7 Lesson 3 Sexual and Asexual Reproduction

11. What is sexual reproduction?
•When an egg is fertilized by a sperm cell, a new
cell, called a zygote, is formed. It has a full set of
genetic material.
•The zygote develops into a new organism. It
grows through mitosis.
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 7 Lesson 3 Sexual and Asexual Reproduction

12. Unit 7 Lesson 3 Sexual and Asexual Reproduction
Odd Reproduction
Copyright © Houghton Mifflin Harcourt Publishing Company
•Multicellular organisms can reproduce asexually.
•Some do this by parthenogenesis, in which the
female produces young without fertilization.
•Other organisms reproduce asexually by
regeneration.
•Other organisms reproduce asexually by
fragmentation, in which segments fall off and
become new organisms.

13. Added Advantage
Copyright © Houghton Mifflin Harcourt Publishing Company
What are the advantages of each type
of reproduction?
•Asexual reproduction has its advantages.
•It allows an organism to reproduce very quickly,
and ensures that any favorable traits the parent
has are passed on to the offspring.
•Reproduction can occur without a partner, and all
offspring can reproduce.
Unit 7 Lesson 3 Sexual and Asexual Reproduction

14. What are the advantages of each type
of reproduction?
•Sexual reproduction has its advantages.
•It increases genetic variation. Offspring have
different traits, which improves the chance that at
least some will survive.
•Some organisms can use both types of
reproduction. This allows them to spread quickly,
and adapt to changes in the environment as well.
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 7 Lesson 3 Sexual and Asexual Reproduction