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Coquita the Crocodile

Middle school learnscience.org

Name Date

Predict

Coquita the crocodile lived alone at a reptile park in Costa Rica for 16 years. She never met a male. Then she laid 14 eggs. Could one of those eggs have a baby inside?

Circle one. Yes / No

Why?

Watch

  1. Virgin birth in a crocodileyoutube.com/shorts/9Fil5Efiz9o
  2. Coquita’s virgin birth is not a cloneyoutube.com/shorts/PkigBKfd-oU

Word of the day

Parthenogenesis (par-theh-no-JEN-uh-sis). A baby grows from an egg that was never fertilized, meaning no sperm ever joined the egg.

Word partComes fromMeaning
partheno-Greek parthénosmaiden, virgin
-genesisGreek génesisorigin, birth
  • The Parthenon in Athens got its name from Athena Parthenos, “Athena the Virgin.”
  • You can spot gen inside gene and genetics too. Gen means birth or origin.

Bonus word from video 2. Homozygous (ho-mo-ZY-gus). Homo- means “same.” Zyg- comes from the Greek word for joined, like in zygote. Homozygous means both copies of a gene match.

Questions

  1. Most babies get half their DNA from mom and half from dad. Coquita’s baby got all of its DNA from Coquita. How was the DNA in Coquita’s baby different from your DNA?

    Hint. Most babies get one copy of each gene from mom and one from dad. Who gave Coquita’s baby both copies?

  2. Some female reptiles can store sperm inside their bodies for years. How could scientists prove Coquita’s baby didn’t come from old, stored sperm?

    Hint. A baby made with sperm carries some DNA from a dad. What could scientists check in Coquita’s baby?

  3. Coquita’s baby didn’t survive to hatch. What did scientists still learn from Coquita’s baby?

    Hint. Coquita’s baby was fully formed. What does a fully formed baby tell you about crocodile eggs?

  4. American crocodiles like Coquita are a vulnerable species, which means they’re at risk of becoming endangered. The scientists who studied Coquita say zoos should test eggs from females that live alone, instead of throwing those eggs away. How could testing eggs from crocodiles that live alone help American crocodiles?

    Hint. When a species is in danger, every new baby counts. What could zoos find inside eggs from females that live alone?

Exit ticket

Coquita’s baby had only one parent, and the baby still wasn’t a clone. A mixed pair is two different copies of a gene, like one working copy and one broken copy. How is Coquita’s baby different from a clone?

Hint. A clone is an exact copy of its mom. Did Coquita’s baby keep Coquita’s mixed pairs?

Sources