BIO 101 - Genetics

In human cells, at the end of mitosis and after cytokinesis, how many chromosomes have moved into each daughter cell?

46

At the start of mitosis, how many sister chromatids are present in a human cell?

92

Why don't plant cells use a contractile ring to divide their daughter cells?

A contractile ring can't "pinch" a cell wall.

Which of the choices is a characteristic of meiotic cell division?

Cell division results in the production of gametes.

Which of the statements is true regarding binary fission?

DNA replication of the circular bacterial chromosome during binary fission is a bidirectional process, starting at one point but progressing in opposite directions

Why would a compound that interferes with bacterial cell wall synthesis be useful for treating a bacterial infection?

It would prevent cell division and thus prevent growth of the bacterial population

Replication of DNA in a eukaryote occurs during which phase of the cell cycle?

S phase

Which of the statements is true about gametes?

They fuse to form a new organism during fertilization.

In which phase of mitosis do kinetochore microtubules shorten?

anaphase

In which phase of mitosis do sister chromatids separate?

anaphase

During what step in meiosis do homologous chromosomes separate?

anaphase I

When do sister chromatids separate in meiosis?

anaphase II

The process of cell division in a prokaryotic cell is called:

binary fission

Sexual reproduction results in an increase in genetic diversity because:

during metaphase I, the homologous chromosomes line up in a random orientation so that gametes inherit a random set of maternally and paternally derived chromosomes. The random orientation of bivalents assures that gametes receive a random mix of maternal and paternal homologs. This happens in the formation of eggs and sperm, so the zygote formed from their fusion creates a random mix from both parents. Recombination in prophase I mixes regions of maternal and paternal homologs to provide more genetic diversity. during fertilization, the gametes that fuse are random so that a large number of chromosomal combinations are possible in the new organism.during prophase I, genes that are paternally and maternally derived recombine so that the gametes have chromosomes that are different from the parents' chromosomes.

A human cell with a total of 23 chromosomes is:

haploid.

In which phase of mitosis do chromosomes line up at the middle of the cell?

metaphase

The division of genetic material in a eukaryotic cell is called:

mitosis.

In which phase of mitosis do chromosomes condense?

prophase

Crossing over occurs during which step in meiosis?

prophase I

Reproduction by mitotic cell division

results in two daughter cells that are genetically identical.

In which phase of mitosis does the nuclear envelope reform?

telophase

Mitotic cell division is considered asexual because:

the daughter cells receive DNA from one parent cell, and the daughter cells are genetically identical.

The centrosome is:

the microtubule organizing center for the mitotic spindle.

Synapsis is best described as:

the pairing of homologous chromosomes in prophase I.

Construction of a karyotype from an image of stained chromosomes is a technique by which a researcher can see and count chromosomes.

true

The alignment of chromosomes at metaphase of meiosis II is most similar to the alignment of chromosomes during metaphase of mitosis.

true