meiosis

What is a genome?

The complete complement if an organisms genes

Which of the following statements about genes is incorrect?

One gene is used in a specific cell type

Asexual reproduction and sexual reproduction differ in all but which of the following ways

Asexual reproduction is utilized only by fungi and protists, whereas sexual reproduction is utilized by only plants and animals.

Asexual reproduction results in identical offspring unless which of the following occurs

Mutation

A gene’s location along a chromosome is known as which of the following?

Locus

What is a karyotype?

A display of every pair of homologous chromosomes within a cell, organized according to size and shape

The human X and Y chromosomes

Include genes that determine an individual’s sex

Which of the following is true of a species that has a chromosome of 2n=16

Each cell has 8 homologous pairs

Eukaryotic sexual life cycles show tremendous variation. Of the following elements which do all sexual life cycles have in common?

II,III, and IV

Which of these statements is false

At sexual maturity, ovaries and testes produce diploid gametes by meiosis

In animals meiosis results in gametes and fertilization results in

Zygotes

Referring to a plant sexual life cycle which of the following terms describes the process that leads directly to the formation of gametes

Gametophye mitosis

Which of the life cycles is typical for animals

I only

Which of the the life cycles is typical for plants and some algae

III only

Which of the life cycles if typical for most fungi and some protists

I and II

In a life cycle such as that shown in part III of figure 13.1 if the zygotes chromosome number is 10 which of the following will be true.

The sporophyte’s chromosome number per cell is 10 and the gametophyte is 5

The probable source of error would be a mistake in which of the following?

Either anaphase I or II

A given organism has 46 chromosomes in its karotype. We can therefore conclude which of the following

It’s gametes must have 23 chromosomes

After telophase I of meiosis I, the chromosomal makeup of each daughter cell is

Haploid, and the chromosome are each composed of two chromatids

How do cells at the completion of meiosis compare with cells that have replicated their DNA and are just about to begin meiosis

They have half the number of chromosomes and one fourth the amount of DNA

Tetrads of chromosomes are aligned at the equator of the splinde alignment determines indecent assirtment

II

Synapses of homologous pairs occurs, crossing over may occur

I

Centromeres of sister chromatids disjoin and chromatids separate

VII

Which of the following happens at the conclusion of meiosis I

Homologous chromosomes are separated

Which diagram represents prophase I of meiosis

IV

A cell divides to produce two daughter cells that are genetically different

The statement is true for meiosis I only

Homologous chromosomes synapse and crossing over occurs

The statement is true for meiosis I only

Chromatids are separated from each other

The statement is true for mitosis and meiosis II

Independent assortment of chromosome occurs

The statement is true for meiosis I only

What would you look for if you wanted to identify metaphase I cells on the slide?

Tetrads lined up at the center of the cell

If the cells were from a plant which sample might represent a gametophyte cell

III

Which sample of DNA might be from a nerve cell arrested in G0 of the cell cycle

I

What sample might represent an animal cell in G 2 phase of the cell cycle

II

What sample might represent a sperm cell

III

From the descriptions above, which of the following is the order that most logically illustrates a sequence of meiosis

5,2,4,3,1

Which of the following occurs in meiosis but not mitosis

Synapsis of homologous chromosomes

A Tetrads includes which of the following sets of DNA strands

Two sets of sister chromatids that have synapsed

Chasmata are what we see under a microscope that let us know which of the following is occurring

Crossing over

How does the sexual life cycle increase genetic variation in a species

By allowing indecent assortment of chromosomes

Independent assortment of chromosomes is a result of

The random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I

When pairs of homologous chromosomes separate during anaphase I

The sister chromatids remain attached to one another

Natural selection and recombination due to crossing over during meiosis I are related in which of the following ways?

Recombinants may have combinations of traits that are favored by natural selection.

A human cell containing 22 autosomes and a Y chromosome is a

Sperm

Meiosis II is similar to mitosis in that

Sister chromatids separate during anaphase

If the DNA content of a diploid cell in the G1 phase of the cell cycle is X the the DNA content of the same cell at metaphase of meiosis I would be

2x

How can you tell the cell is undergoing meiosis not mitosis

The two homologous chromosomes that are aligned are starting to separate

Identify the stage of meiosis shown figure 13.5

Metaphase 3

All eukaryotic sexual life cycles include

Mitosis meiosis gamete formation and fertilization

What is the advantage of sexual reproducers over asexual reproducers when exposed to an unstable environment

Sexual reproducers give genetically diverse offspring giving them a better chance at survival

When homologous chromosomes cross over what is the result

Specific proteins break into two strands of nonsister chromatids and rejoin them