An endosperm develops when the

a. pollen grain begins to form.
b. pollen grain sticks to a stigma.
c. sperm fertilizes the central cell.
d. sperm fertilizes an egg


C

Biology & Microbiology

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Chromosomes other than those involved in sex determination are known as

a. nucleosomes. b. heterosomes. c. alleles. d. autosomes. e. liposomes.

Biology & Microbiology

Mendel referred to the expressed trait in the F1 generation as _____. The unexpressed trait in the F1 generation was referred to as _____. For example, the purple flowering trait is dominant and the white flowering trait is recessive.

Fill in the blank(s) with the appropriate word(s).

Biology & Microbiology

The drug used for several protozoan infections is

A. metronidazole. B. sulfa drugs. C. griseofulvin. D. nystatin. E. amphotericin B.

Biology & Microbiology

The deamination of cytosine generates a uracil base. This is a naturally occurring nucleic acid base, and so does not represent a DNA lesion caused by damage due to chemicals or irradiation

Why is this base recognized as "foreign" and why is it important for cells to have a mechanism to recognize and remove uracil when it is found in the DNA duplex?

Biology & Microbiology