Connect 11.1-11.4: Sexual Reproduction and Meiosis

Typically, how many cells contribute genetic material during sexual reproduction?

Two

Sperm and egg cells are known as which of the following?

Gametes

When two gametes (a sperm and an egg) unite, they produce a single cell called a(n) ______________

zygote

Which of the following statements accurately describes meiosis?

Meiosis is a special division that produces gametes with half the normal number of chromosomes.

An organism is diploid when its cells carry which of the following?

Two sets of chromosomes

Eukaryotes that reproduce through_________________ reproduction require two cells to contribute genetic material for the production of the next generation.

sexual

Which of the following are true statements regarding sexual reproduction?

The offspring receives genetic material from two parents.

Haploid cells are produced through meiosis.

The two types of gametes typically produced by multicellular eukaryotic organisms are Blank______.

egg cells

sperm cells

A human gamete contains how many chromosomes?

23

When two gametes fuse, they produce a single cell with twice the chromosomes of each gamete. This new cell is called a(n) Blank_zygote_____.

In most animals, the Blank______ state of the life cycle is much larger than the Blank______ state of the life cycle.

diploid; haploid

__________________is a reduction division which produces cells with half the normal number of chromosomes.

meiosis

What type of division (meiosis or mitosis) does the diploid zygote of an animal have to go through (usually many times) in order to give rise to all of the cells in the adult body?

mitosis

When reproduction is achieved through meiosis and subsequent fertilization, it is called _______________reproduction.

sexual

In animals, the cells that will eventually perform meiosis to produce gametes are called ______________________cells

germ line

A human gamete contains _______chromosomes.

23

Both somatic and germline cells are diploid. However, Blank______.

somatic cells undergo mitosis, while germline cells can undergo meiosis

Select the true statements about the life cycle of sexually reproducing organisms.

In all sexually reproducing organisms, meiosis is required for the production of haploid cells.

The life cycle of sexually reproducing organisms involves alternation between the haploid and diploid stage.

Depending on the organism, either the haploid or the diploid stage can be dominant.

In sexually reproducing organisms, which type(s) of cell division requires two sequential rounds of division?

Meiosis

Which process is responsible for the production of the adult body of an animal from a zygote?

Mitosis

During meiosis, homologous chromosomes become closely associated in the process of pairing, or_____________

synapsis

An organism is diploid when its cells carry which of the following?

Two sets of chromosomes

During prophase I, all four chromatids of the two homologues become closely associated as a result of pairing, forming a structure known as a(n)_________ .

tetrad

When are germ line cells set aside from somatic cells?

Early in development

Which of the following accurately pairs animal somatic and germline cells with the number of chromosomes in them.

Somatic cells:diploid; Germline cells:diploid

A result of crossing over is genetic__________ ; this leads to increased genetic variation in the offspring.

recombination

How many rounds of cell division are required for meiosis?

2

What is the name for the sites of crossing over in a chromosome?

Chiasmata

In many species, homologues become connected during meiosis I by a complex structure called the Blank______.

synaptonemal complex

Anaphase of mitosis separates Blank______ while anaphase I of meiosis separates Blank______.

sister chromatids; homologues

When used to characterize the first meiotic division, the term "reductive division" refers to the reduction of which of the following?

Number of chromosomes

When the alleles of genes that were formerly on separate homologues can be found on the same homologue which of the following has occurred?

Recombination has occurred

Meiosis has how many rounds of DNA replication?

1

The sites of crossing over are called _________

chiasmata

During which stage of meiosis do synapsis and crossing over occur?

Prophase I

During meiosis, homologous chromosomes become closely associated in the process of pairing, or__________

synapsis

The tight association of sister chromatids in a tetrad during prophase I is known as Blank______.

sister chromatid cohesion

Identify the difference between metaphase of mitosis and metaphase of meiosis I.

The chromosomes align singly in mitosis and in pairs in meiosis I.

Recombination nodules are structures that contain the enzymes needed for Blank______.

crossing over

Which of the following is sometimes referred to as a reductive division?

Meiosis I

Choose the reasons why sister chromatids do not separate from each other during the first meiotic division.

They are held together by cohesin proteins.

They are held together via sites of crossing over.

In meiosis, when does DNA replication occur?

Before meiosis I only

During meiosis I, the_____________ of sister chromatids function as a unit, attaching to microtubules originating from the same pole.

kinetochores

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

prophase

During meiosis I, chromosomes exhibit ______________attachment because each homologue is attached to one pole instead of sister chromatids becoming attached to opposite poles

monopolar

What does the term sister chromatid cohesion refer to?

The tight association of sister chromatids in a tetrad during prophase I

Which of the following is a unique behavior of kinetochores that allows the separation of homologous chromosomes during meiosis I?

Monopolar attachment

A recombination____________ contains the enzymatic machinery necessary to break and rejoin the chromatids of homologous chromosomes.

nodule

After crossing over is complete, the homologous chromosomes remain attached at the chiasmata. How many chromatids are attached at this point?

4

During _______________I of meiosis, the homologues are pulled toward opposite poles of the cell.

anaphase

During meiosis I, the kinetochores of sister chromatids act as

a unit, to which polar microtubules attach.

In meiosis, the random orientation of homologous chromosomes on the metaphase plate leads to Blank______.

independent assortment of maternal and paternal chromosomes in the gametes

During meiosis I, each homologue is attached to one pole. This is called Blank______.

monopolar attachment

At which stage of meiosis I have the chromosomes reached their respective poles, where they begin to decondense.

Telophase

Some cells can undergo meiosis with segregation, in which meiosis proceeds without recombination.

achiasmate

At the end of anaphase I in meiosis, each pole of the cell contains which of the following?

A haploid set of duplicated chromosomes

The sister chromatids are separated during which phase of meiosis II?

Anaphase

During anaphase I, a pole may receive either the maternal or paternal homologue from each chromosome pair. This means that the genes on different chromosomes assort_______

independently

After meiosis is complete which of the following are produced?

Four daughter cells that are haploid

The sister chromatids found in the daughter nuclei at the end of telophase I are not identical to each other due to which of the following?

Crossing over

When meiosis occurs without recombination, which of the following has occurred?

Achiasmate segregation

Aneuploid gametes are produced by which of the following?

Nondisjunction during meiosis

Which of the the following events is observed during metaphase II?

Alignment of individual chromosomes along the metaphase plate

Of the following choices, which is a similarity between mitosis and meiosis?

The number of chromosomes in the parent cell

When a cell undergoes meiosis, 4 daughter cells are produced. In terms of the number of chromosomes, each daughter cell contains a________________ nucleus.

haploid

In yeast, the Rec8 protein replaces the Scc1 protein in the cohesin complex during meiosis. Why is this important?

This allows the sister chromatids to stay together during meiosis I.

Sister chromatid cohesion is maintained during which process?

Meiosis I

A unique event in meiosis I is Blank______.

homologous pairing

The destruction of the Rec8 protein on chromosome arms allows for which of the following to occur?

Separation of homologues in anaphase I

Which of the following is a meiosis-specific cohesin protein in yeast?

Rec8

The process of recombination begins with the introduction of a double strand break into one of the homologs. This has led scientists to believe that the enzymatic machinery responsible for recombination first evolved Blank______.

as a mechanism for the repair of dsDNA breaks

According to one hypothesis, DNA replication is suppressed between meiosis I and II by which of the following?

Cyclin B

Which of the following must occur during anaphase I?

Meiosis specific cohesins must be removed from chromosome arms, but not from sister centromeres.

Which type(s) of cellular division produce(s) cells that are not genetically identical to the mother cell?

Meiosis

During meiosis I the sister kinetochores are attached to Blank______.

the same pole

How can the maintenance of low levels of cyclin B between meiosis I and II potentially suppress DNA replication?

By preventing the formation of replication initiation complexes

The four daughter cells produced by meiosis are Blank______.

not genetically identical to each other