Understanding concepts of cell biology. | Homework Helpers

1) Where would we expect the most active cell cycling?

A) nerve cells

B) skeletal muscle cells

C) bone marrow stem cells producing blood cells

D) All cells cycle at the same general rate.

E) when the cell is in interphase.

2) Synthesis of DNA

A) occurs during prophase.

B) occurs during anaphase.

C) occurs during all stages of meiosis.

D) occurs during interphase.

E) is necessary to mitosis but not to meiosis.

3) The best characterization of apoptosis is

A) the unwanted, unexpected death of a cell.

B) cell death is a normal consequence of a cell living long enough to eventually be killed by accident.

C) killer cells approach a healthy cell and determine when it will die.

D) cell death as the result of preprogrammed  internal cell events.

E) cell death which negatively affects the organism.

4) Chromosomes

A) have numbers that increase with evolution; primitive organisms have few, advanced have many.

B) consist of coiled and condensed chromatin.

C) occur in full haploid pairs (2n) or single diploid strands (n).

D) are inherited by each parent contributing homologous pairs.

E) All of the above are true.

5) When DNA is coiled on histones and twisted into short condensed strands, it is called

A) chromosomes.

B) chromatin.

C) centrioles.

D) genes.

E) nucleosomes.

6) During ____, the nuclear envelope disappears, and the chromosomes become distinct.

A) telophase

B) anaphase

C) metaphase

D) prophase

E) interphase

7) Crossing-over occurs during

A) metaphase I.

B) metaphase II.

C) prophase I.

D) prophase II.

E) anaphase I.

8) In organisms that are parthenogenetic, females produce young that are female without any fertilization of eggs occurring.  Which process(es) could theoretically accomplish this through alteration of the normal meiotic cycle?

A) A haploid egg develops into a female; females only complete meiosis I.

B) A polar body fuses with the egg nucleus in place of the sperm and females complete meiosis.

C) Meiosis stops before anaphase, telophase or cytokinesis occurs, leaving a full diploid individual.

D) All of the above would theoretically produce parthenogenesis if the offspring was viable.

9) What are alleles?

A) genes for different traits, such as hair color vs. eye color

B) alternative forms of a gene for a particular trait, such as blue eyes or brown eyes

C) the locations of genes on a chromosome

D) recessive forms of a kind of characteristic carried by genes

E) dominant forms of a kind of characteristic carried by genes

10) For Mendel’s law of segregation to occur, the alleles must be

A) at different loci on the same chromosome.

B) on a homologous pair of chromosomes.

C) on a non-homologous pair of chromosomes.

D) at the same loci on the same chromosome.