WALT: UNDERSTAND THE PURPOSE OF REPRODUCTION AND THE
DIFFERENCE BETWEEN SEXUAL AND ASEXUAL REPRODUCTION
WILF:
• Understand the purpose of reproduction
• Identify if an organism reproduces sexually or asexually
• Understand that differences between sexual and asexual
reproduction
Cytokinesis
Metaphase
Cell splits into 2 identical cells
Pieces align for split
Interphase
Cells resting phase
Prophase
Pieces moving into position
Anaphase
Telophase
Separation begins
2 new cells are forming
Asexual and Sexual Reproduction
Asexual Reproduction
Sexual Reproduction
One Parent
Two Parents
No sex cells
Sex cells: Sperm and Egg
Offspring produced by cell division
(mitosis)
Sperm and egg join = fertilisation
Offspring identical to parent (same DNA)
Offspring look different from parent
(mixed DNA)
Most unicellular organisms reproduce
this way (prokaryotes and single-celled
eukaryotes)
Sexual reproduction is by far the most
prevalent form of reproduction among
multicellular organisms (eukaryotes).
https://www.youtube.com/watch?v=fcGDUcGjcyk
Types of Reproduction (5 mins)
Advantages/Disadvantages of asexual reproduction
Advantages
• Organism can reproduce quickly
• Offspring are identical to the parent
• Parent does not need partner to reproduce
• All organism are able to reproduce (male or female)
Disadvantages
• Less resistant
• Less Diverse
Asexual reproduction
Examples of organisms that reproduce asexually
•
•
•
•
Sea Star
Strawberry
Certain Bacteria
Yeast
Advantages/Disadvantages of sexual reproduction
Advantages
• Genetic diversity
• Unique organisms
• Offspring have different traits that increase chances for survival (important
especially for environmental change)
Disadvantages
• Longer time for offspring to develop and mature
• Occurs less often
• Always required to find a mate
Sexual reproduction
• All the members of the Animal Kingdom
•
•
•
•
•
•
Fish
Mammals
Amphibians
Birds
Reptiles
Insects
Asexual Reproduction
Sexual Reproduction
Number of parents
One Parent
Genetic info compared to
the parents
Same
Different
Same
Different
Complexity of organism that
uses this method
Simple
Complex
Simple
Complex
Example of an organism
that uses this method
Bacteria
Two Parents
Mammals, Fish, Reptiles
5) Classify the following as either Sexual or Asexual Reproduction.
a) A small piece of a cactus breaks off the plant, falls to the ground, and begins to
grow.
Asexual
b) Pollen from a male poplar tree fertilizes sex cells on a female poplar tree.
Sexual
c) Two earthworms each produce sperm and eggs and fertilize each other.
Sexual
d) A flatworm is cut in half and grows into two flatworms.
Asexual
Gametes
• Eukaryotes produce specialised reproductive cells called gametes.
• The male gamete is the sperm cell and the female gamete is the egg
cell or ovum.
(ii)
sperm
ovum
Egg cells and Sperm cells
Structural features:
• Central nucleus containing genetic material
• Cytoplasmic ‘yolk’ containing nutrients
• Outer layered coating surrounding the plasma
membrane
Structural features:
• Central nucleus containing genetic
material
• Cytoplasmic ‘yolk’ containing
nutrients
• Outer layered coating surrounding the
plasma membrane
Checking for Understanding
Thumbs up – Completely understand
Sideways thumb – Somewhat understand
Thumbs down – Do not Understand
• Understand the purpose of reproduction
• Identify if an organism reproduces sexually or asexually
• Understand the differences between sexual and asexual reproduction
Before you leave
Why does reproduction occur?
Name 3 animals that sexually reproduce?
Name 3 animals that asexually reproduce?
Next Lesson……..
8 (min) flowering plants video