Warmup Monday 1/28
• On Page 4 in SNB: Write at
least two sentences
summarizing Friday’s DNA Lab
• Finish the BrainPOP DNA
Activity & Quiz
Unit 3 – Evolution,
Heredity and Genetics
What questions will I be able to answer by
the end?
• How do I inherit my traits?
• What is the probability that my children will have
curly or straight hair?
• How does my body repair itself when I break a bone
or get a cut?
• How have ducks acquired webbed feet over time?
• Why are polar bears white?
• I have freckles but my sister doesn’t. How does this
happen?
Asexual vs. Sexual
Reproduction
Key Point
Reproduction is the ability
for an organism to make
more of its kind.
Key Points
1. Cells come from other living cells.
2. Cells reproduce (make more cells)
by dividing into two.
3. This is called mitosis, and it is a
form of asexual reproduction.
Asexual reproductionKP-One parent organism produces
two or more offspring* that have
the same genetic material as the
parent.
Ex: Cell splits into two -->
*Offspring – the “child” of a parent
organism
How do Unicellular organisms
reproduce asexually?
Small, unicellular organisms
undergo asexual reproduction
through cell division (mitosis) and
budding.
Asexual reproduction: Cell division
This is an example of
a bacteria
undergoing cell
division.
How many parents?
How many offspring?
Asexual reproduction – Cell division
This is a paramecium
undergoing cell
division.
How many parents?
How many offspring?
We have cell division going on in
our bodies too:
Our body cells go through cell
division for growth and repair:
• One bone cell divides to make 2
new bone cells (we grow taller
over time!)
• One skin cell divides to make 2 new
skin cells (we repair a cut in our skin)
Read the “Cells that
Reproduce” article and
answer the questions
with a partner.
How else do organisms
reproduce asexually?
Asexual Reproduction: Budding
This is a hydra – it is a
sea animal related to
jellyfish. A new
organism is forming
on its side and can
live on its own once it
falls off.
How many parents?
How many offspring?
Budding is…
a form of asexual
reproduction in
which an
organism grows
an offspring
from the side of
its body.
What kind of reproduction is this?
More specifically?
If small organisms and
cells undergo asexual
reproduction, how do
larger, more complex
organisms like humans
reproduce?
Sexual reproduction
•
•
•
•
Occurs in larger, complex organisms
Step 1: Meiosis creates gametes
Step 2: Gametes unite to form offspring (fertilization)
Gametes:
– Sperm cell (male)
– Egg cell (female)
• Involves 2 parents and one or many offspring.
• Produces high variation
Ex: human sperm fertilizes a human egg and a new
organism is formed.
Let’s Practice
• Cut out the images given to you.
• With your partner, try to determine which
side of the chart they belong on – asexual
reproduction or sexual reproduction.
• Raise your hand when you are done. I will
come around to check before you glue.
• Fill in the blanks and answer the questions on
the worksheet entitled Asexual vs. Sexual
Reproduction Practice.