(Mod) Sci 8A Checkpoint 04: Modern Genetics

Which of these is a pigment?

• chlorophyll

• carbon dioxide

Why are some parts of a plant white?

• The white parts absorb all colors except white.

• The white parts reflect all colors of light.

How do purple pigments make flower petals look purple?

• Purple pigments absorb purple light and reflect other colors. Only purple light stays in the pigment, so it looks purple.

• Purple pigments absorb all colors except purple. Purple light is reflected, so the petal looks purple.

What is the difference between a dominant and a recessive color allele in pea plants?

• Both alleles make pigments. The recessive pigment is white.

• A dominant allele makes pigment proteins. A recessive allele does not make these proteins.

Which statement about chromosomes is correct?

• C. A gene is made of one allele on a chromosome. Sex cells have that allele.

• D. A gene has two alleles on separate chromosomes. Sex cells have one allele for each gene.

Which statement shows a similarity between Mendel’s findings and chromosome behavior in cell division?

• Mendel found that two parents give genes to offspring. In cell division, the cell loses half its chromosomes and then makes more to replace them.

• Mendel found that two parents give genes to offspring. In cell division, chromosomes split, and half go to each new cell.

Which cases cannot be explained by Mendel’s genetics? (Select all that apply.)

• A. A person with a short and a tall parent is as tall as the tall parent.

• B. A person with a short and a tall parent has a height between the two parents.

• C. A person with a short and a tall parent is as tall as the short parent.

• D. A person with a short and a tall parent is shorter than the short parent.

Which human trait shows a wide range of variations instead of just two types?

• hair color

• cleft chin

Which traits are likely controlled by more than one gene?

• eye color from light to dark

• height from short to tall

• having a widow’s peak or not

• hair color from light to dark

Why do leaves look green?

• Chlorophyll absorbs red and blue light but reflects green light.

• Leaves do not contain any pigments that interact with light.