Question

14 multiple choice 1 point
in one statement, what is sexual reproduction?
the production of two haploid cells, one from each of two parents, and the subsequent fusion of two diploid cells to form a single, unique aneuploid cell
the production of two haploid cells from a single parent which unite to form a diploid cell.
the production of two haploid cells, one from each of two parents, and the subsequent fusion of two haploid cells to form a single, unique diploid cell.
the production of two diploid cells, one from each of two parents, and the subsequent fusion of two diploid cells to form a single, unique tetraploid cell
15 multiple choice 1 point
defects in homeostasis leading to abnormally high cell division may predispose an organism to
apoptosis
prion disease
cancer
mutations
16 multiple choice 1 point
during the cell cycle, cell ensure that all dna is replicated, that dna is not damaged, and that the cell has the protein and nucleic acid reserves necessary to proceed with cell division.
centrioles
endonucleases
cyclins
checkpoints

Explanation:

Question 14

Sexual reproduction involves two parents. Each parent contributes a haploid cell (gamete). When these haploid gametes fuse, they form a diploid zygote. Analyzing each option:

• Option 1: Fusion of diploid cells is incorrect for sexual reproduction (gametes are haploid).
• Option 2: Two haploid cells from a single parent is asexual reproduction (like in some plants' self - fertilization, but not the general sexual reproduction definition).
• Option 3: Correct as it follows the process of gamete (haploid) formation from two parents and their fusion to form a diploid zygote.
• Option 4: Diploid cells from parents and formation of tetraploid is not the normal sexual reproduction process (normal is diploid zygote from haploid gametes).

• Apoptosis is programmed cell death, not related to high cell division.
• Prion disease is related to misfolded proteins (not cell - division - related in this context).
• Cancer is characterized by uncontrolled cell division (abnormally high cell division due to homeostasis defects).
• Mutations can cause changes but the direct consequence of high cell division is cancer in this context.

• Centrioles are involved in cell division (spindle formation) but not in checking DNA replication etc.
• Endonucleases cut DNA (not for checking replication etc.).
• Cyclins regulate the cell cycle (but not specifically for ensuring DNA replication and no damage).
• Checkpoints in the cell cycle (like G1/S, G2/M checkpoints) ensure DNA is replicated, not damaged, and the cell has resources for division.

Answer:

C. The production of two haploid cells, one from each of two parents, and the subsequent fusion of two haploid cells to form a single, unique diploid cell.

Question 15