Student Exploration: Inheritance
Vocabulary: acquired trait, asexual reproduction, clone, codominant traits, dominant trait, offspring, recessive trait, sexual reproduction, trait
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
How are you similar to your parents?
How are you different?
A trait is a characteristic. Think about your physical traits (eye color, skin tone, height, hair, face, allergies, etc.) What traits do you think you inherited, or received, from your parents?
In the Inheritance Gizmo™ you can create and breed aliens on an imaginary planet. Select Asexual reproduction. During asexual reproduction, a single parent produces offspring (children).
Drag the parent over to the Parent 1 space and press Reproduce. Fill in the Offspring traits on the table above. What traits appear to be inherited from the parent?
Because this offspring inherits its traits from one parent, it is called a clone.
Get the Gizmo ready:
Question: Are all parental traits inherited by offspring?
Observe: In sexual reproduction, two parents pass traits to the offspring. Create and breed a variety of aliens. Record your observations on a separate sheet of paper.
Form a hypothesis: Which traits do you think are passed down from alien parents to their offspring, and which traits are not? Explain.
Experiment: Set the Food supply to 2 bushes. Create two identical parents with thick bodies, green skin, curly antennas, and triangle tattoos. Make two offspring and record their traits in the table below.
Analyze: Compare the offspring traits to the parent traits.
Which traits were passed from parents to offspring?
Which traits were not passed down?
Investigate further: Create offspring with a few different levels of Food supply. How does food supply affect the body type of offspring?
Think and discuss: Suppose a human child had a mother with dyed-pink hair and a father who was missing a finger (lost in an accident). Would the child inherit these traits? Explain.
Get the Gizmo ready:
Question: How is alien skin color inherited?
Predict: What do you think the offspring of a green alien and pink alien will look like?
Experiment: Test your prediction with the Gizmo. What did you find?
When offspring show a mixture of parent traits, the traits are called codominant traits.
Predict: What do you think will happen when you breed two green-and-pink spotted aliens?.
Experiment: Follow the steps below. (You may have already done the first step or two.)
Place a green alien and a pink alien in the locations for Parent 1 and Parent 2.
Breed these parents twice. Drag both offspring to the spaces below the Nest.
Drag the two green-and-pink offspring up to become the new Parent 1 and Parent 2.
Breed these aliens 10 times. Record how many times each skin color occurred in their offspring. (For example, if there were 2 green offspring, write “2” below “green.”)
Analyze: Look at the results of your experiment.
What kind of skin did most of the offspring have?
Did all of the offspring have green and pink skin?
Think and discuss: For a codominant trait, do the offspring of identical parents always look like the parents? Explain your answer.
Get the Gizmo ready:
Question: How is alien antenna shape inherited?
Predict: What do you think will happen when you breed an alien with straight antenna to an alien with curly antenna.
Experiment: Test your prediction using the Gizmo. Create at least 5 offspring. What did you notice?.
Analyze: Sometimes when two traits are combined, one is a dominant trait and the other is a recessive trait. If both traits are present, only the dominant trait is seen in the offspring.
Which trait is dominant, straight antenna or curly?
Which trait is recessive?
Investigate further: Take two of the straight-antenna offspring and breed them together to produce 10 new offspring. Record the antenna type of each offspring.
Did the recessive trait disappear?
How can a trait skip a generation?
Draw conclusions: For a dominant/recessive trait, do the offspring of identical parents always look like the parents? Explain.
Compare: How do the offspring of two parents that reproduce sexually differ from the offspring of a single parent that reproduces asexually?