Genetics Chapter 2, 11.3, and 11.4

How many chromosomes would be expected in a human egg cell?

23

The diploid chromosome number of an organism is usually represented as 2n. Humans have a diploid chromosome number of 46. What would be the expected haploid chromosome number in a human?

23

An interesting group of ants consists of several virtually identical, closely related species, with females having chromosome numbers of 18, 20, 32, 48, 60, 62, and 64. If one crossed a female of species (A) with 32 chromosomes and a male species (B) with 9 chromosomes (males are haploid, and each gamete contains the n complement), how many chromosomes would one expect in the body (somatic) cells of the female offspring?

25

In an organism with 52 chromosomes, how many bivalents would be expected to form during meiosis?

26

If a typical somatic cell has 64 chromosomes, how many chromosomes are expected in each gamete of that organism?

32

For the purposes of this question, assume that a G1 somatic cell nucleus in a female Myrmecia pilosula contains 2 picograms of DNA. How much DNA would be expected in a metaphase I cell of a female?

4 picograms

What is the diploid chromosome number for humans?

46

Which of the following is a prime number?

5

What type of chromosome has a centromere located very close to, but not on, the end of the chromosome?

Acrocentric

What stage of meiosis is characterized by the separation of the sister chromatids?

Anaphase II

If two chromosomes of a species are the same length and have similar centromere placements and yet are not homologous, what is different about them?

Both genetic content and banding pattern

Which technique can be used to specifically identify areas of a chromosome that are composed of heterochromatin?

C-banding

Which statement accurately describes a diploid cell?

Contains 2 copies of each chromosome

What process involves the shuffling of the genetic information between the two members of a homologous pair?

Crossing over

During interphase of the cell cycle, ________.

DNA content essentially doubles

What process leads to the creation of "sister chromatids"?

DNA replication

Which of the following statements regarding haploidy is true?

Each haploid cell contains one chromosome of each homologous pair of chromosomes

What cellular structures are involved in the synthesis of the majority of a cell's proteins?

Rough endoplasmic reticulum and ribosomes

How are the chromosomes organized during mitosis metaphase?

Sister chromatids align along the equatorial plane of the cell

Organized by centrioles, what structures are important in the movement of chromosomes during cell division?

Spindle fibers

Which of the following statements about results of meiosis is correct?

The chromosome number is reduced by one-half.

Diploid cells contain homologous chromosomes. While homologous chromosomes are very similar and contain the same loci, they are not identical. Which statement correctly explains why homologous chromosomes are not identical?

The two members of a homologous pair originated from different parents/different individuals

How are viral genomes and eukaryotic genomes similar?

They have the ability to pack a genome into a small volume

Which statement best describes the overall function/purpose of interphase?

To duplicate the majority of the cell's internal contents

A bivalent at pachytene contains four chromatids.

True

A chromosome may contain one or two chromatids in different phases of the mitotic or meiotic cell cycle

True

An organism with a diploid chromosome number of 46 will produce 2^23 combinations of chromosomes at the end of meiosis.

True

An organism with a haploid number of 10 will produce 1024 combinations of chromosomes at the end of meiosis.

True

If a typical G1 nucleus contains 2C (two complements) of DNA, a gamete that is haploid (n) contains 1C of DNA.

True

If a typical G1 nucleus is 2n and contains 2C (two complements) of DNA, a prophase I cell is 2n and contains 4C of DNA

True

S phase is the part of interphase when DNA duplication takes place

True

The centromere of a chromosome separates during anaphase

True

The meiotic cell cycle involves two cell divisions but only one DNA replication

True

Eukaryotic chromosomes contain two general domains that relate to the degree of condensation. These two regions are ________.

called heterochromatin and euchromatin

In order to control the cell cycle, cyclins interact with

cyclin dependent kinases

What is the name of the membranous structure that compartmentalizes the cytoplasm of eukaryotic organisms?

endoplasmic reticulum

Living organisms are categorized into two major groups based on the presence or absence of a nucleus. What group is defined by the presence of a nucleus?

eukaryotic organism

Chromatin of eukaryotes is organized into repeating interactions with protein octomers called nucleosomes. Nucleosomes are composed of which class of molecules?

histones

The failure of the chromosomes to separate normally during cell division is called

nondisjunction

Crossing over normally involves an exchange of genetic material between all of the following except

nonhomologous chromosomes

What is the outcome of synapsis, a significant event in meiosis?

side-by-side alignment of homologous chromosomes

During meiosis, chromosome number reduction takes place in anaphase II.

False

What stage is characterized by cells that are not actively dividing (i.e. proliferating)?

G0 phase

Which of the following statements about heterochromatin is FALSE?

Heterochromatin replicates early in the S phase

What term refers to the proteins that the DNA wraps and organizes around?

Histones

How does crossing over contribute to genetic variation?

It creates new DNA sequence combinations