Which stage of meiosis do sister chromatids still attached at the centromere line up along the equator?

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Which event takes place during anaphase II?

Possible Answers:

Sister chromatids line up in the center of the cell

Homologous chromosomes are separated

Homologous chromosomes line up in the center of the cell

Sister chromatids are separated 

Correct answer:

Sister chromatids are separated 

Explanation:

During prophase I, homologous chromosomes form tetrads along the center of the cell. Full chromosomes are pulled to each pole during anaphase I, resulting in two haploid cells at the end of meiosis I. During prophase II, sister chromatids align at the center of the cell in singular chromosome structures. These sister chromatids are separated during anaphase II, resulting in a total of four haploid cells.

What is the first stage of meiosis during which a cell is considered haploid?

Possible Answers:

Prophase II

Telophase II

Metaphase I

Anaphase I

Correct answer:

Prophase II

Explanation:

A diploid cell will have two copies of each chromosome, known as a homologous pair. A haploid cell will only have one copy of each chromosome, though the chromosome may consist of two sister chromatids.

Diploid cell: (XX)

Haploid cell: (X)

During meiosis I, the cell is diploid because the homologous chromosomes are still located within the same cell membrane. Only after the first cytokinesis, when the daughter cells of meiosis I are fully separated, are the cells considered haploid. Following this first division, the cell begins meiosis II with prophase II, making this the first haploid meiotic stage.

What occurs during the S phase of the cell cycle?

Possible Answers:

The cell enters a state in which it neither divides, nor is preparing to divide

The cell's chromatin condenses and forms chromosomes

DNA is replicated, resulting in two identical sister chromatids attached at the centromere

The cytoplasm splits and forms two diploid daughter nuclei

The cell grows in size, prepares mRNA and proteins, and prepares to divide

Correct answer:

DNA is replicated, resulting in two identical sister chromatids attached at the centromere

Explanation:

The S phase occurs between the G1 and G2 phases and is the stage during which DNA is replicated, and then checked for defects. Depending on the level of nutrients and energy available, the cell will either enter the G0 phase or the M phase.

During the G1 phase, the cell replicates organelles and grows in size. During the G2 phase, DNA is checked for damage and the cell prepares to divide. The M phase refers to mitosis, while the G0 phase refers to quiescence—a period during which the cell is not preparing for division.

During which phase of meiosis does DNA begin to condense?

Possible Answers:

Anaphase I

Telophase I

Metaphase II

Prophase I

Metaphase I

Correct answer:

Prophase I

Explanation:

Mitosis is also known as "karyokinesis." "Karyo-" refers to the nucleus. (Remember that eu-KARY-ote means true ("eu-") nucleus, and pro-KARY-ote means before ("pro-") nucleus.) The "-kinesis" part of "karyokinesis" comes from the same roots as "kinetic" and refers to movement. Thus, mitosis is the movement of the nucleus. Packing of the DNA occurs in prophase of mitosis so that it's easier to move rather than having to move the loose chromatin. Think of moving forty-six strands of hundreds of yards of yarn—we would want it to be tightly coiled to make it manageable.

Meiosis is the process by which a ___________ cell is formed from a ___________ cell.

Possible Answers:

haploid . . . diploid

haploid . . . haploid

diploid . . . diploid

diploid . . . haploid

Correct answer:

haploid . . . diploid

Explanation:

Meiosis is the process by which a haploid cell is formed from a diploid cell. The difference between haploid cells and diploid cells is that haploid cells contain one complete set of chromosomes, whereas diploid cells contain two complete sets of chromosomes. Meiosis involves the division of a diploid (2n) parent cell. The chromosomes are duplicated, but carry out two consecutive divisions. The result is four haploid (n) cells, each with half the number of chromosomes as the parent cell due to the separation of homologous pairs in meiosis I.

In contrast, mitosis is the process by which a diploid parent cell produces two diploid daughter cells.

Which three events most accurately describes what occurs in meiosis I?

Possible Answers:

Homologous chromosomes pair, cross over, then separate

Sister chromatids pair, cross over, then separate

Sister chromatids are duplicated, pair, then cross over

Homologous chromosomes are duplicated, pair, then separate

None of these occur in meiosis I

Correct answer:

Homologous chromosomes pair, cross over, then separate

Explanation:

In meiosis I, the homologous chromosomes have already been duplicated in S phase of interphase. The sister chromatids are identical at this stage. Homologous chromosomes pair in prophase I, forming tetrads. The tetrads then cross over, exchanging genetic material. Then, the genetically-mixed tetrads line up on the metaphase plate and are separated in anaphase I. Note that after the first meiotic division, the two daughter cells are nonidentical and are haploid.

Meiosis produces __________ daughter cells. 

Explanation:

Meiosis involves two divisions and results in four unique daughter cells called gametes. Meiosis begins with one parent cell, after the first division there are two daughter cells, and then those each split, resulting in a total of four daughter cells.   

Homologous chromosomes pair up in which stage of meiosis?  

Possible Answers:

Prophase I

Prophase II

Metaphase I

Metaphase II

Correct answer:

Prophase I

Explanation:

In prophase I chromosomes become compact and homologous chromosomes pair up. Also during prophase I, the nuclear membrane begins to break down and the spindle apparatus begins to form.

Homologous chromosomes line up along the cell's equator in which stage? 

Possible Answers:

Anaphase I 

Metaphase II

Metaphase I

Anaphase II

Correct answer:

Metaphase I

Explanation:

In metaphase I, homologous chromosomes line up along the center of the cell in order to be pulled apart. Recall that during meiosis I, homologous chromosomes pair, cross over, and separate. Meiosis II is when the sister chromatids are separated.

Sister chromatids separate in which stage of meiosis?                   

Possible Answers:

Telophase I

Anaphase II

Anaphase I

Telophase II

Correct answer:

Anaphase II

Explanation:

Chromatid disjunction occurs in anaphase II after the chromosomes line up along the equator during metaphase II. The chromosomes are then pulled apart, with one chromatid moving north, and one moving south. The next steps are telophase, and cytokinesis, which upon completion, will result in genetically distinct haploid gametes.

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In what phase of meiosis do the sister chromatids line up at the equator?

During metaphase, the kinetochore microtubules pull the sister chromatids back and forth until they align along the equator of the cell, called the equatorial plane.

During which stage do the sister chromatids split at the centromere?

Anaphase: During anaphase, the centromere splits, allowing the sister chromatids to separate.

What phase of mitosis is where the chromosome line up at the equator?

Metaphase. Next, chromosomes assume their most compacted state during metaphase, when the centromeres of all the cell's chromosomes line up at the equator of the spindle. Metaphase is particularly useful in cytogenetics, because chromosomes can be most easily visualized at this stage.

During what stage of mitosis the pairs of sister chromatids will be lined up at the center of the cell?

Metaphase. Chromosomes line up at the metaphase plate, under tension from the mitotic spindle. The two sister chromatids of each chromosome are captured by microtubules from opposite spindle poles. In metaphase, the spindle has captured all the chromosomes and lined them up at the middle of the cell, ready to divide.