Download Sc9 - a 2.2(teacher notes)

Learning outcomes:
1 I can distinguish between asexual and sexual reproduction.
2 I can describe examples of each type of reproduction.
2.2 . Asexual and Sexual Reproduction
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involves only one parent.
All of the offspring are identical to the parent.
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There are different types of asexual reproduction:
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Binary Fission –
 only single-celled organisms reproduce in this
way.
 The cell splits into two cells and each one is
identical.
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Budding –
 the parent organism produces a bud (a smaller
version of itself), which eventually detaches
itself from the parent and becomes a selfsufficient individual - identical to the parent.
 Coral also reproduces in this way, but do not
detach themselves
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Spore Production –
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spores are similar to seeds, but are produced
by the division of cells on the parent, not by the
union of two cells.
 One parent may produce many spores, each of
which will grow into a new individual, identical to
its parent.
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Vegetative Reproduction –
 is the reproduction of a plant not involving a
seed, including; cuttings, runners, suckers,
tubers.
Which is which???
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Usually involves two organisms.
The offspring have a mix of characteristics: half from each parent.
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Gametes are essential for sexual reproduction: reproductive cells
that have one role – to join with another during reproduction.
o Ex: sperm and Egg are gametes
*** This is super important to know.
Male gametes = sperm cells.
Female gametes = egg cell.
During mating, the SPERM CELL and EGG CELL unite. This creates one
entity, the ZYGOTE.
The zygote is the first complete cell of the individual. Each and every cell
will be then be duplicated by splitting in half: the size of each cell stays the
same. (we call this process of duplication: MITOSIS)
These cells duplicate until an EMBRYO is developed. The EMBRYO then
continues to then develop into a FOETUS.
*** This is super important to know.
 Like animals, plants reproduce thanks to male and female gametes
uniting.
 Except most plants contain both male gametes and female gametes.
Only a few plants have one or another.
 Like animals, these gametes unite, during FERTILIZATION, to
form a ZYGOTE that then develops into an EMBRYO.
Pollen = male gametes. These are
located on the STAMEN.
Ovules = female gametes. These are
located on the PISTIL.
Cross-pollination occurs when
pollen from one plant is carried to
the stigma of another plant by wind,
water or animals (bees or
butterflies).
Asexual (advantages):
 Reproduce very quickly
 Can build population very quickly (bacteria)
Asexual (disadvantages):
 When the environment changes, they all die if cannot adapt.
Sexual (advantages):
 Provides lots of variation.
 This variation means the populations can survive when the
environment changes.
Sexual (disadvantages):
 It takes a lot of energy to reproduce.
 It takes a lot of time.
 This makes the populations much, much smaller
Online Activity: comparing asexual and sexual reproduction
Graph analysis
1. What is the subject?
2. What conclusion can be made with this diagram?
3. What can be inferred by this diagram?
> Create a visual diagram of either:
- Asexual reproduction methods
- Sexual reproduction for plants
- Sexual reproduction for animals.
Diagram must include Visual diagram that explains the concept and brief
explanation paragraph at bottom of page.
 Optional (But great review for exam): Venn diagram or table that
compares advantages and disadvantages of both Sexual and Asexual
reproduction.
 Optional: Questions from page 36 and 37
 Exam on Unit A section 1.1 – 2.2