meiosis

Crossing over is best described as

It involves a physical exchange of chromosome segments in the tetrad

During the cell cycle, when does DNA replication occur

Prior to mitosis Prior to meiosis

The bivalents are organized along the metaphase plate, with the sister chromatids randomly aligned in a double row. What phase of cell division is described here?

Metaphase of meiosis I

In mitosis, a pair of sister chromatids is attached to both poles while in meiosis I a pair of sister chromatids is attached to just one pole via kinetochore microtubules. What phase is described here?

Prometaphase

What metaphase I event provides a mechanism for vast genetic diversity?

Random alignment

In what phase of meiosis are sister chromatids separated?

Anaphase II

True or false: DNA replication occurs between the first and second meiotic divisions.

False

two key events occur at the beginning of meiosis but not mitosis?

Formation of bivalents Crossing over

describe meiosis I in humans?

Genetic diversity is generated. Chromosome pairs are separated. Two haploid cells are produced.

compare mitosis and meiosis.

Sister chromatids are separated during both mitosis and meiosis. Crossing over occurs in meiosis but not normally in mitosis.

characteristics of meiosis II?

The resulting daughter cells are haploid The sorting event is similar to that of mitosis Sister chromatids are separated

Which of the following is the end result of mitosis in a diploid organism?

Two daughter cells that are diploid

The sister chromatids are separated during _____ II of meiosis

anaphase

After crossing-over occurs, the chromosome arms tend to separate but remain attached at a site of crossover. This connection is called a(n)

chiasma

A key difference between meiosis and mitosis is the process of_____ ______ , which occurs commonly during meiosis (in prophase I), but rarely during mitosis.

crossing over

The end result of meiosis II (after cytokinesis) is

four daughter cells that are haploid

A human _____ only contains 23 chromosomes

gamete

A bivalent is formed when _____ pairs of sister chromatids associate with each other, lying side by side

homologous

What occurs during anaphase I of meiosis?

homologous pairs of chromatids move to opposite poles

Exchange of chromosome segments between homologues at the beginning of meiosis

increases genetic variation in offspring

In prometaphase, there is a key difference between mitosis and meiosis I. In mitosis, a pair of sister chromatids is attached to both poles. In meiosis I a pair of sister chromatids is attached to just one pole via ______ microtubules.

kinetochore

Bivalent formation and crossing over are two key events that typically occur at the beginning of what?

meiosis

Homologous chromosomes are separated from each other during

meiosis I only.

The synaptonemal complex connects homologous chromosomes during what?

meosis

During ______, homologous chromosomes align along the center of the cell as bivalents, or tetrads.

metaphase 1

During metaphase I of meiosis, the bivalents are organized along the ____ _____. In particular, the sister chromatids are randomly aligned in a double row rather than in a single row as in mitosis. Listen to the complete question

metaphase plate

_____ I of meiosis, the replicated chromosomes condense, the homologous chromosomes form bivalents, and crossing over occurs.

prophase

When does crossing over typically occur?

propshase of meiosis 1

During metaphase I of meiosis, the bivalents are organized along the metaphase plate. In particular, the sister chromatids are

randomly aligned in a double row.

Put the events of meiosis I in order, beginning with the earliest event at the top.

replicated chromosomes condense, form bivalents, and crossing over occurs nuclear envelope is completely broken down and spindle apparatus is formed bivalents are aligned along the center of the cell homologous chromosomes are separated and move towards opposite poles chromosomes condense and nuclear envelope is reformed

In prometaphase I of meiosis, the nuclear envelope is completely broken down into vesicles, and the _____ apparatus is completely formed

spindle

Crossing over occurs commonly during meiosis but rarely during mitosis because during prophase of meiosis I, the homologues____ to form

synapse

The process of forming a bivalent is termed pairing, or

synapsis

of meiosis I, the joined pairs of sister chromatids have reached their respective poles, and they then decondense

telophase

Homologous pairs of sister chromatids associate with each other to form a

tetrad.

True or false: Meiosis II and mitosis have similar sorting events, but different starting points.

true