airbai

The period from the beginning of one division to the beginning of the next is known as the __.

cell cycle

The cell cycle is divided into two periods: __ and mitosis.

interphase

Interphase can be divided into three stages: G1, __, and G2.

S

During the S phase, the cell __ its genetic material.

replicates

Identical strands of DNA are called __.

sister chromatids

The structure that holds chromatids together is called the __.

centromere

Each chromatid requires its own __ to be considered a chromosome.

centromere

If the DNA is too damaged to repair, the cell can undergo __, or programmed cell death.

apoptosis

The proteins that help regulate the cell cycle are called __ and cyclin-dependent kinases.

cyclins

Mutated genes that can induce cancer are known as __.

oncogenes

Tumour suppressor genes can trigger __ if the damage is too severe to be repaired.

apoptosis

Mitosis occurs in four stages: prophase, metaphase, __, and telophase.

anaphase

During prophase, the __ envelope disappears and chromosomes condense.

nuclear

In metaphase, chromosomes align at the __ plate.

metaphase

In anaphase, chromosomes are pulled away from the __.

center

Cytokinesis, which occurs during __, ends mitosis.

telophase

Mitosis produces daughter cells that are __ copies of the parent cell.

identical

Meiosis is the production of __.

gametes

In males, the gonads are the __, while in females they are the ovaries.

testes

Meiosis contributes to genetic __ through processes such as synapsis and crossing-over.

variation

Meiosis I consists of four stages: prophase I, __ I, anaphase I, and telophase I.

metaphase

During prophase I of meiosis, chromosomes line up side-by-side in a process called __.

synapsis

Crossing-over during prophase I allows for the exchange of segments between non-sister __ chromosomes.

homologous

In metaphase I, homologous pairs line up at the __ plate.

metaphase

During anaphase I, the __ are separated to opposite poles of the cell.

homologs

At the end of telophase I, the cells undergo __, resulting in two daughter cells.

cytokinesis

The second meiotic division is known as _ II.

meiosis

During prophase II, chromosomes condense and become __ again.

visible

In anaphase II, sister chromatids are pulled to opposite ends of the __.

cell

Meiosis is also known as __.

gametogenesis

If the egg cell is produced, the process is called __.

oogenesis

Nondisjunction results in the wrong number of __ in a cell during meiosis.

chromosomes

Individuals with Down syndrome have __ copies of the 21st chromosome instead of two.

three

Nondisjunction can occur during __ I or anaphase II.

anaphase

The presence of an abnormal number of chromosomes is referred to as __.

aneuploidy

The three phases of interphase are G1, S, and __.

G2

To induce cell cycle progression, an inactive CDK binds a regulatory __.

cyclin

Cell cycle checkpoints are control mechanisms that ensure cell division is happening __ in eukaryotic cells.

properly

The process where cells produce organelles, proteins, and enzymes during G1 and G2 is called __ reactions.

metabolic

Cell cycle checkpoints function mainly at phase __, such as G1/S transition and G2/M transition.

boundaries

During telophase II, a nuclear membrane forms around each set of __.

chromosomes

Meiosis produces haploid cells (n) that combine to restore the __ (2n) number during fertilization.

diploid