Download Animal Reproduction - morgan boenke teaches science

ANIMAL REPRODUCTION LAB
DAPHNIA MAGNA- FIRST PART
You will be provided with a jar containing an organism called Daphnia magna. Daphnia are about the
size of the head of a pin.
1. Take a jar with Daphnia inside and try to observe the Daphnia swimming. They move with jerky
motions so you may be able to find them by searching for a jerkily swimming object.
2. Using a pipette suck up a Daphnia and some water by squeezing the pipette bulb, inserting into
the water near a Daphnia, and releasing the bulb to suck up the Daphnia.
3. Once you have captured a Daphnia in the pipette gently squirt it out into a depression slide.
4. Once the Daphnia is in depression make sure that a little water is there to keep it alive. Try to
keep just a few drops so that there is less area for the Daphnia to swim in. This will make it
easier to see under the microscope since it will have to stay in one place.
5. Set the plastic slide on the microscope stage (platform) and turn on the microscope.
6. Using the lowest power lens, which is the smallest and has a red line on it, try focusing your
microscope on the Daphnia.
7. Once you can see the Daphnia look to see if you can see different parts of its body.
8. Draw the Daphnia in the space below. What different parts of its body can you make out? What
do you think these different parts do?
9. Do you see anything along the back of the Daphnia?
Can you describe what you see?
What do you think these are?
BROWN HYDRA- FIRST PART
You will be provided with a jar contain an organism called Hydra oligactis. Hydra are a bit bigger than
Daphnia.
1. Take a jar with some Hydra inside and try to observe them. Hydra generally stay in the same
place. You will likely find them stuck to the inside of the jar. Look for their tentacles (long wavy
arms) to help you locate them.
2. Using the pipette capture a Hydra the same way you captured a Daphnia.
3. Move the Hydra to a depression slide just as you moved the Daphnia. Ensure that there is a little
water to keep the Hydra alive but not so much that it’s hard to find Hydra.
4. Set the plastic slide on the microscope stage (platform) and turn on the microscope.
5. Using the lowest power lens, which is the smallest and has a red line on it, try focusing your
microscope on the Hydra.
6. Once you can see the Hydra look to see if you can see different parts of its body.
7. Draw the Daphnia in the space below. What different parts of its body can you make out? What
do you think these different parts do?
8. Why do you think that scientists choose the name “Hydra” for this organism?
How many Hydra are in the picture you drew?
DAPHNIA
SECOND PART
Above is a labelled diagram of a Daphnia. Compare it to the drawing you just made. Find as many of
the organs and body parts as you can. Use this to help you identify and label the parts of your own
drawing.
What kind of an organism do you think Daphnia is? Why?
Is Daphnia an animal?
Why or why not?
What characteristics and behaviours did you observe?
Is Daphnia a vertebrate?
Does it have a spine or bones?
What organs does it have?
How does it feed itself ? Can it make its own food through photosynthesis?
Why do you think this?
How do you think it reproduces? Why
HYDRA
SECOND PART
Above is a labelled diagram of a Hyrdra. Compare it to the drawing you just made. Find as many of
the organs and body parts as you can. Use this to help you identify and label the parts of your own
drawing.
PART THREE
WHAT ARE DAPHNIA?
Daphnia are crustaceans. This is a
group of animals that includes
lobsters and crabs. Crustaceans
are known for their hard
exoskeleton. They have no bones
inside their body, instead their
skeleton is on their exterior.
Crustaceans are closely related to
insects.
HOW DO DAPHNIA FEED?
Daphnia are herbivores and feed
by filtering algae out of the water.
Food moves from the mouth,
through the digestive tract and is
expelled out of the anus. Daphnia
have special branched appendages
that help them filter out debris
and unwanted material from
entering their mouths.
HOW DO DAPHNIA REPRODUCE?
Female Daphnia produce eggs that
they hold inside their bodies.
Female Daphnia can produce eggs
asexually. They do not need males.
Generally these unfertilized or
“parthenogenetic” eggs develop
only into females.
Daphnia can also reproduce
sexually. This produces a special
resting egg which is designed to
survive winter and hatch in the
spring when environmental
conditions are better for survival.
HYDRA
THIRD PART
WHAT ARE HYDRAS?
Hydra are animals from a group of called “Cnidarians”
(pronounced like Nigh-dairy-ans). Hydra are closely related
to the animals that form coral reefs. Hydra’s live in fresh
water while coral reefs are found in salt water.
Coral reefs are formed by giant colonies of hydra like
organisms that are attached to one another and cooperate
to survive. Coral reefs are animals. Jellyfish are also related
to hydras and coral reefs.
HOW DO HYDRAS EAT?
(AND GO TO THE BATHROOM)?
Hydra catch prey with their tentacles and special
poisonous darts that they store in the cells of their
tentacles. Hydra are predators and carnivores. This means
they hunt other animals to eat. They attach themselves to
a surface and wait for a prey item to swim past them.
When a prey item passes by, like a Daphnia, they attack it
with their special dart cells (cnidocytes…..is this word like
anything you have read so far?). This cells are common to
all animals in the same group as hydras, cnidarians.
Eventually the prey is immobilized by the poison, captured
in the hydras tentacles and swallowed whole.
Hydra are very simple organisms. They are only two cells
thick. They have a mouth but no anus, so waste products
are excreted through their mouth. Imagine if you had to do
this…
HOW DO HYDRAS REPRODUCE?
Hydra can reproduce sexually. Each individual has the
ability to make both sperm and eggs. This means that each
hydra is both male and female. An individual that is both
male and female is called a hermaphrodite.
Hydra can also reproduce asexually. They do this by
sprouting another individual that is attached to them
through “budding”, the same word we use to describe how
a plant grows. Eventually the new bud grows large enough
and separates to live on its own. Some species of hydra live
together in colonies on many individuals that do not
separate from each other after they grow asexually
through budding.