Question

What observation led researchers to propose that chloroplasts evolved from cyanobacteria?
Both produce proteins.
Both contain mitochondria.
Both provide structure to cells.
Both perform photosynthesis.

Which factor can decrease the rate of a chemical reaction?
low activation energy
high pressure
low temperature
high concentration of enzyme

Drosophila eye color is an X-linked trait. Red eye color is dominant, and white eye color is recessive. Which Punnett square shows a cross in which the probability that offspring will be red-eyed males is 25 percent?

A Punnett square is shown. The columns are labeled Upper X r and Upper Y. The rows are labeled x Upper R and x Upper R. Clockwise, from top-left, the boxes include: X Upper R X r, X Upper R Y, X Upper R Y, X Upper R X r.

A Punnett square is shown. The columns are labeled Upper X r and Upper Y. The rows are labeled x Upper R and x r. Clockwise, from top-left, the boxes include: Upper X r Upper X r, Upper X r Upper Y, Upper X r Upper Y, Upper X r Upper X r.

A Punnett square is shown. The columns are labeled Upper X r and Upper Y. The rows are labeled x r and x r. Clockwise, from top-left, the boxes include: Upper X r Upper X r, Upper X r Upper Y, X r Upper Y, Upper X r Upper X r.

A Punnett square is shown. The columns are labeled Upper X Upper R and UpperY. The rows are labeled x r and x r. Clockwise, from top-left, the boxes include: Upper X r Upper X Upper R, Upper X r Upper Y, X r Upper X Upper R, Upper X r Upper X Upper R.

What is the next step in the process after a substrate enters the active site of an enzyme?
The chemical reaction occurs.
New substances called products are formed.
The enzyme and the substrate bind to form the enzyme-substrate complex.
The enzyme and the products bind to form the enzyme-products complex.

Kai looks at a photo of herself with her parents. She notices that, while her features are similar to her parents’ features, they do not appear to be identical.

Which explains why this is the case?
Their DNA is made of different codon sequences.
Their DNA is made of four different bases.
Kai inherited more proteins from one parent than the other.
Kai inherited different amino acids from either of her parents.

The chemical equation of photosynthesis includes 6O2. Which best describes this substance?
a solid used during photosynthesis
a gas used during photosynthesis
a liquid produced during photosynthesis
a gas produced during photosynthesis

Which statement describes the F1 generation of a Mendelian monohybrid cross between two true-breeding parents?
Only the dominant trait is visible in the F1 generation.
Only the recessive trait is visible in the F1 generation.
Neither the dominant nor recessive trait is visible in the F1 generation.
Both the dominant and recessive traits are visible in the F1 generation.

Which term refers to a solution with a higher solute concentration outside the cell than inside the cell?
hypertonic
hypotonic
equitonic
isotonic

Answer 1

1) Both perform photosynthesis.

2) Low temperature

3) The second Punnett square (columns: X^r and Y; rows: X^R and X^r) — option B.

4) The enzyme and the substrate bind to form the enzyme–substrate complex.

5) Their DNA is made of different codon sequences.

6) A gas produced during photosynthesis.

7) Only the dominant trait is visible in the F1 generation.

8) Hypertonic