Mitosis

In dividing cells, most of the cells growth occurs during______.

Interphase

During mitosis, microtubules attach to chromosomes at the________.

Kinetochores

Nucleoli are present during _____.

Nucleoli are present during interphase.

Which of the following events would cause the cell cycle to arrest?

Poor nutrient conditions would arrest the cell cycle at the G1 checkpoint.

DNA replication creates to identical DNA molecules, called_________, which separate during mitosis.

Sister chromatids

During prophase a homologous pair of chromosomes consists of _____.

At this point each of the chromosomes consists of two chromatids.

Spindle fibers attach to kinetochores during _____.

Attachment of spindle fibers to kinetochores is one of the events of prometaphase.

The parent cell that enters meiosis is diploid, whereas the four daughter cells that result are haploid.

DNA content is halved in both meiosis I and meiosis II. Ploidy level changes from diploid to haploid in meiosis I, and remains haploid in meiosis II.

Which of the following is a function of the S phase in the cell cycle?

DNA replication occurs during S phase and results in two sister chromatids for each original chromosome.

True or false? The M phase is characterized by the replication and division of a cell's chromosomes.

Cells replicate their chromosomes during the S phase and divide partition their chromosomes during the M phase.

Chromosomes become visible during _____.

During prophase, the chromatin fibers become discrete chromosomes.

During _____ both the contents of the nucleus and the cytoplasm are divided.

The mitotic phase encompasses both mitosis and cytokinesis.

During interphase most of the nucleus is filled with a complex of DNA and protein in a dispersed form called_________.

Chromatin

The copying of chromosomes occurs during which of the following phases of the cell cycle?

Chromosomes must undergo replication before mitosis can occur; this copying occurs during the S phase.

In most eukaryotes, division of the nucleus is followed by_________, when the rest of the cell divides.

Cytokinesis

Cytokinesis often, but not always, accompanies _____.

Cytokinesis often, but not always, accompanies telophase.

Centromeres divide and sister chromatids become full-fledged chromosomes during _____.

During anaphase, sister chromatids separate and daughter chromosomes migrate to opposite poles.

The________is a cell structure consisting of microtubules, which forms during early mitosisand plays a role in cell division.

Mitotic Spindles

If an organism normally has 34 chromosomes, how many molecules of DNA should there be in the G1 phase of the cell cycle?

There is one DNA molecule per chromosome (34)

During _____ the cell grows and replicates both its organelles and its chromosomes.

These are the events of interphase.

For the first several divisions of early frog embryos, cells proceed directly from the M phase to the S phase and back to M without gaps. Which of the following is likely to be true about dividing cells in early frog embryos?

Without gap phases, the cells have no opportunity to grow

After chromosomes condense, the________is the region where the identical DNA molecules are mostly tightly attached to each other.

Centromeres

The________are the organizing centers for microtubules involved in separating chromosomes during mitosis.

Centrosomes