Exam 1 Chapter 3

tetrad

A bivalent is also called a .............., because it is composed of four chromatids.

two pairs of sister chromatids

A bivalent, or tetrad, consists of ______. Multiple choice question. two chromatids of a replicated chromosome two pairs of sister chromatids two non-homologous chromosomes a sister chromatid and a non-sister chromatid

Blank 1: homologous or homolog Blank 2: meiosis

A fundamental principle of the chromosome theory of inheritance involves the chromosome composition of cells. Most eukaryotic cells are diploid, containing chromosomes that are found in ................. pairs. During the process of .......................... , the two members of each pair segregate into different daughter nuclei.

homolog meiosis

A fundamental principle of the chromosome theory of inheritance involves the chromosome composition of cells. Most eukaryotic cells are diploid, containing chromosomes that are found in ....................... pairs. During the process of ................. , the two members of each pair segregate into different daughter nuclei.

autosomes

A human cell contains two main types of chromosomes: sex chromosomes and ......................

A = synaptonemal complex ; B = chiasma

A pair of homologous chromosomes is shown here. Which of the following combinations show correct matches? Multiple choice question. A = chiasma ; B = synaptonemal complex A = synaptonemal complex ; B = chiasma A = cleavage furrow ; B = synaptonemal complex A = cleavage furrow ; B = chiasma A = synaptonemal complex ; B = cleavage furrow

40 chromosomes, each consisting of two chromatids

After a mitotic division is complete, a daughter cell has 40 chromosomes. Which of the following best describes the chromosome composition of the mother cell in the G2 phase? Multiple choice question. 40 chromosomes, each consisting of two chromatids 80 chromosomes, each consisting of two chromatids 40 chromosomes, each consisting of one chromatid 80 chromosomes, each consisting of one chromatid

chromatids

After replication, each chromosome consists of two copies called ................

chromosome replication occurs during the S phase of the cell cycle

All of the following are fundamental principles of the chromosome theory of inheritance except ______.

the connections that result from crossing-over

Chiasmata refers to ______. Multiple choice question. the cleavage furrow that forms during cytokinesis protein complexes that help in chromosome replication the connections that result from crossing-over a stage in prophase I of meiosis

the structures within living cells that contain the genetic material

Chromosomes are best defined as ______. Multiple choice question. the units of inheritance that code for proteins the structures within living cells that hold the nucleus in place the structures within living cells that contain the genetic material the units of inheritance that are composed of RNA

autosomes

Chromosomes that are not sex chromosomes are called ______. Multiple choice question. autosomes euchromatin protosomes heterochromatin

sex chromosome

Chromosomes that determine whether an individual is a male or female are called ........................

Anaphase I of meiosis

Consider a diploid cell with 2n = 6. This cell is shown in which phase of cell division? Multiple choice question. Metaphase of mitosis Anaphase I of meiosis Metaphase II of meiosis Anaphase II of meiosis Anaphase of mitosis

four; eight

Consider an organism that has four pairs of chromosomes. At the end of meiosis I, each cell would have ______ chromosomes and ______ chromatids. Multiple choice question. four; eight two; four eight; eight four; four

three; six

Consider an organism that has three pairs of chromosomes. At the start of meiosis II, each cell would have ______ chromosomes and ______ chromatids. Multiple choice question. six; six six; three three; three three; six

prometaphase I

During ______ ______ of meiosis, the spindle apparatus is complete and the chromatids are attached via kinetochore microtubules. Multiple choice question. telophase I prometaphase I anaphase II prophase II

telophase I

During ______ of meiosis, the pairs of sister chromatids (or dyads) reach the opposite poles of the cell, where in most cases, they decondense. Multiple choice question. anaphase I metaphase I metaphase II telophase I prophase II

kinetochore microtubule

During metaphase I of meiosis, one pair of chromatids in a bivalent (but not both) is attached to a ______. Therefore, each pair of sister chromatids is attached to only one pole. Multiple choice question. centrosome polar microtubule nucleolus metaphase plate telomere kinetochore microtubule

synapsis

During prophase of meiosis I, homologous chromosomes recognize and begin to align with each other via a process called .............

centrosomes spindle

During prophase of mitosis, the nuclear membrane breaks down into small vesicles and the nucleolus becomes less visible. Furthermore, the two ................ move apart from each other and the mitotic .................. begins to form.

Metaphase of meiosis I

During which of the following phases are tetrads organized along a plate in the center of the cell? Multiple choice question. Prophase of meiosis II Metaphase of mitosis Prophase of meiosis I Metaphase of meiosis II Metaphase of meiosis I

centrioles,

Each centrosome of an animal cell contains a pair of ................... at right angles to each other.

cell cycle

Eukaryotic cells that are destined to divide progress through G1, S, G2, and M phases, which are collectively known as the ......................

meiosis

Eukaryotic cells that are diploid can divide by ______ to produce haploid sex cells. Multiple choice question. binary fission meiosis mitosis multiple fission

linked

Genes that are physically located on the X chromosome are called X- .............. genes.

metaphase I

In ______ of meiosis, the bivalents (which are also termed tetrads) are aligned along the center of the cell. Multiple choice question. prophase II metaphase II anaphase II prophase I anaphase I metaphase I

testcross

In a Drosophila melanogaster ................., a fly with a dominant phenotype and unknown genotype is mated to one that has a recessive phenotype.

interphase

In actively dividing cells, the G1, S, and G2 phases are collectively known as .................

meiosis

In eukaryotes, ______ is the type of cell division that is responsible for the production of gametes. Multiple choice question. mitosis meiosis binary fission

Blank 1: embryo Blank 2: sac

In flowering plants, the female gametophyte is a seven-celled structure called the....................

pollen grain

In flowering plants, the male gametophyte with a thick cell wall is called the ......................

is the same for all individuals of the species

In general, the chromosome number of a particular species ______. Multiple choice question. is the same for all individuals of the species varies depending on the environmental conditions varies depending on the age of the individual is different for males and females of the species

heterogametic, homogametic

In humans, the male is known as the ............... sex, because one type of sperm carries only the X chromosome, and another type carries the Y chromosome. The female, on the other hand, is the ................... sex because all eggs carry a single X chromosome. Listen to the complete question

non-sister; homologous

In meiosis, crossing over refers to the physical exchange of pieces between ______ chromatids of ______ chromosomes. Multiple choice question. sister; non-homologous non-sister; non-homologous sister; homologous non-sister; homologous

X0 XX

In the X-0 system of sex determination, the male's chromosomes are listed as .................. , whereas the female's chromosomes are listed as ................

Blank 1: synaptonemal Blank 2: complex Blank 3: chiasma, bivalent,

In this figure label A points to the ..............., while label B shows the , ................... which is the connection that results from a crossing over.

spermatogenesis

Male animals produce mature sperm by a process called

anthers ovary

Meiosis in flowering plants occurs in two different parts of the sporophyte: the ..................., which produce the male gametophyte, and the ................., which produce the female gametophyte.

segregation

Mendel's law of .............. can be explained by the homologous pairing and separation of chromosomes during meiosis.

binary fission

Most bacterial cells divide by ______. Multiple choice question. mitosis budding binary fission fragmentation

nucleoid

Prokaryotes usually have a single type of circular chromosome in a region of the cytoplasm called the ______. nucleoplasm nucleus nucleolus nucleoid

Blank 1: bacteria Blank 2: archaea

Prokaryotes, which include the .............. and the ..................., are organisms that lack a membrane-bound nucleus. Listen to the complete question

The chromatids become condensed. The mitotic spindle begins to form. The nucleolus becomes less visible. The nuclear membrane begins to dissociate into small vesicles

Select all of the following events that occur during prophase. Multiple select question. The two centrosomes are replicated. The chromatids become condensed. The mitotic spindle begins to form. The nucleolus becomes less visible. The nuclear membrane begins to dissociate into small vesicles

Homologues have reached their respective poles The nuclear membrane reforms in most species

Select all of these that are events of telophase I of meiosis. Multiple select question. The nuclear membrane breaks down in most species Homologues have reached their respective poles The nuclear membrane reforms in most species Chromosomes condense in most species Homologues are aligned at the center of the cell

gametes ; fertilization

Sexual reproduction involves the fusion of two ______ in the process of ______. Multiple choice question. gametes ; gametogenesis somatic cells ; gametogenesis somatic cells ; fertilization gametes ; fertilization

testes

Spermatogenesis takes place in the ______. Multiple choice question. seminal vesicles prostate gland testes penis

homologous chromosomes recognize each other and begin to align themselves in prophase I.

Synapsis is the process by which ______.

anaphase

The .................. stage of meiosis I is characterized by the separation of the two pairs of sister chromatids within a bivalent from each other and their migration to opposite poles of the cell.

nucleoid

The ................... of a prokaryotic cell is the region of cytoplasm that contains the chromosome.

Sry

The ..................... gene on the Y chromosome plays a key role in causing the development of male characteristics.

mammals

The X-Y system of sex determination is used by ______. Multiple choice question. birds mammals reptiles plants insects

The homologs segregate during meiosis I and the sister chromatids separate during meiosis II

The behavior of chromosomes during meiosis explains Mendel's law of segregation. Specifically, a gamete contains only one copy of each type of chromosome because of which of the following? Multiple choice question. The homologs segregate during meiosis I and then again during meiosis II The homologs segregate during meiosis I and the sister chromatids separate during meiosis II The sister chromatids segregate during meiosis I and then again during meiosis II The sister chromatids segregate during meiosis I and the homologs separate during meiosis II

region of the chromosome where the sister chromatids join

The centromere is a ______. Multiple choice question. complex of proteins that helps in replicating DNA complex of proteins that forms at the site of cell division region of DNA that serves as an origin of replication region of the chromosome where the sister chromatids join

Blank 1: Boveri Blank 2: Sutton

The chromosome theory of inheritance was a milestone in our understanding of genetics. It was independently proposed by Theodore ......................, a German biologist, and American geneticist Walter .......................

female gametophyte

The embryo sac is the _______ in flowering plants. Multiple choice question. female sporophyte male gametophyte male sporophyte female gametophyte

four; G1, G2, S, and M

The eukaryotic cell cycle is composed of ______ phases called ______. Multiple choice question. four; G1, G2, S, and M three; G1, G2, and M four; G0, G1, G2, and S three; G1, G2, and S

crossing over

The interchange of corresponding chromatid segments of homologous chromosomes during prophase I of meiosis is called ______ ______. crossing over assortment mutation segregation

gametophyte sporophyte

The life cycles of plant species alternate between haploid and diploid generations. The haploid generation is called the ................... , whereas the diploid generation is called the...............

G2 G1

The meaning of the term chromosome can differ depending on the stage of the cell cycle we are observing. During ................... phase of interphase and early stages of M phase, a chromosome refers to a pair of sister chromatids (a dyad). However, at the end of M phase and during .................................................phase of interphase, a chromosome refers to a monad which contains the equivalent of one chromatid.

male gametophyte

The pollen grain is the ______ in flowering plants. Multiple choice question. male gametophyte female gametophyte female sporophyte male sporophyte

distribute the replicated chromosomes equally into the two daughter cells

The primary purpose of mitosis is to ______. Multiple choice question. ensure proper replication of the genetic material during the S phase of the cell cycle distribute the replicated chromosomes equally into the two daughter cells enhance the genetic diversity of a species via crossing-over between chromosomes

independent assortment

The random arrangement of homologs along the metaphase plate in meiosis I is consistent with Mendel's law of.............................

chiasma

The structure that is formed during crossing over is called a(n) .............., because it looks like the Greek letter chi, χ.

chromosomes

The structures within all living cells that contain the genetic material are called .

chromosome

The term that can refer to either a dyad (pair of sister chromatids) or a monad (single chromatid) is a(n) ....................

centromere

The two chromatids of a chromosome are joined together at a region of DNA called the ......................

sister chromatids

The two copies of a replicated chromosome are called ______. Multiple choice question. homologous chromosomes centrosomes alleles sister chromatids

centrosomes

The two microtubule-organizing centers (MTOCs) that form the mitotic spindle of animal cells are called ______. Multiple choice question. centrosomes centrophores centromeres centrioles

Anaphase II of meiosis

This diagram represents a cell that has an original diploid number (2n) of six chromosomes. The cell is shown in which phase of cell division?

binary fission

This figure shows a bacterium reproducing asexually by a process known as .......................

True

True or false: A heterogametic sex produces two types of sex cells, while a homogametic sex produces sex cells of only one type. True false question.TrueFalse

True

True or false: Each species has a particular chromosome composition. True false question. True False

False

True or false: Most eukaryotic species are haploid or have such a phase as a significant part of their life cycle. True False

False

True or false: Sex chromosomes are chromosomes that determine sex in all species. True false question. True False

asexual

Unicellular prokaryotic organisms proliferate by .................. reproduction, in which a preexisting cell divides to produce two new cells.

Independent alignment of different homologous pairs along the metaphase I plate

What aspect of chromosome behavior is consistent with Mendel's law of independent assortment? Multiple choice question. Movement of sister chromatids to opposite poles during anaphase II of meiosis Replication of chromosomes during the S phase prior to meiosis Independent alignment of different homologous pairs along the metaphase I plate Production of genetically identical daughter cells during mitosis

A complex between DNA and proteins that is found in eukaryotic cells

What is chromatin? Multiple choice question. Another term for the DNA molecule found in a prokaryotic cell Another term for the DNA molecules found in a eukaryotic cell A complex between DNA and proteins that is found in prokaryotic cells A complex between DNA and proteins that is found in eukaryotic cells

chromatin

What is the name for the diffuse complex of DNA and proteins in a eukaryotic cell? Multiple choice question. chromatin nucleoplasm nucleoid chromophore

Sexual reproduction

What process involves the fusion of gametes in fertilization to produce a new organism? Multiple choice question. Mitosis Sexual reproduction Asexual reproduction Binary fission Meiosis

S G2 G1

Which of the following are part of interphase? Multiple select question. S G2 M Cytokinesis G1

A mother cell divides to produce two identical daughter cells

Which of the following best describes asexual reproduction? Multiple choice question. A mother cell divides to produce four unique daughter cells Two haploid gametes fuse to form a diploid cell A mother cell divides to produce two identical daughter cells

One pair of sister chromatids is linked to one pole, and the homologous pair is linked to the other

Which of the following best describes how chromosomes are attached to microtubules during metaphase I of meiosis? Multiple choice question. A pair of sister chromatids is linked to both poles Each member of a homologous pair of chromosomes is linked to both poles One pair of sister chromatids is linked to one pole, and the homologous pair is linked to the other

The two pairs of sister chromatids separate and move to opposite poles.

Which of the following best describes the events of anaphase I of meiosis? Multiple choice question. The two pairs of sister chromatids separate and move to opposite poles. The sister chromatids of each chromosome migrate to opposite poles. The two pairs of sister chromatids migrate to the same pole.

2n → 1n

Which of the following best describes the outcome of meiosis I in humans? Multiple choice question. 1n → 1n 1n → 2n 2n → 2n 2n → 1n

23 dyads

Which of the following best describes the starting material found in each cell entering meiosis II in humans? Multiple choice question. 46 dyads 23 bivalents 23 monads 46 monads 23 dyads

Sry

Which of the following genes plays a key role in male development? Multiple choice question. Yac Sry Xist Xec

A cross between a white-eyed male and a red-eyed female

Which of the following is an example of a testcross in Drosophila melanogaster? Multiple choice question. A cross between a white-eyed male and a red-eyed female A cross between a red-eyed male and a white-eyed female A cross between a white-eyed male and a white-eyed female

Most eukaryotic species are diploid or have a diploid phase to their life cycle.

Which of the following statements about eukaryotes is true? Multiple choice question. All eukaryotic species are diploid or have a diploid phase to their life cycle. Few eukaryotic species are diploid or have a diploid phase to their life cycle. Most eukaryotic species are diploid or have a diploid phase to their life cycle.

Both synapsis and crossing over occur in prophase I of meiosis

Which of the following statements about synapsis and crossing over is true? Multiple choice question. Both synapsis and crossing over occur in prophase I of meiosis Synapsis occurs in prophase I and crossing over occurs in prometaphase I of meiosis Both synapsis and crossing over occur in prometaphase I of meiosis Synapsis occurs in prometaphase I and crossing over occurs in prophase I of meiosis

The male has one sex chromosome (the X) and is designated X0, whereas the female has two X chromosomes.

Which of the following statements about the X-0 system of sex determination is true?

The male is XY and the female is XX.

Which of the following statements about the X-Y system of sex determination is true? Multiple choice question. The female is XX and the male is YY. The male is XY and the female is XX. The female is XY and the male is XX. The male is XY and the female is YY.

The anthers of the sporophyte produce the male gametophyte, while the ovaries of the sporophyte produce the female gametophyte.

Which of the following statements about the life cycle of flowering plants is true?

Certain cells in the sporophyte undergo meiosis to produce haploid cells, which divide by mitosis to produce a gametophyte.

Which of the following statements about the life cycle of plants is true?

prokaryotes

Which term best describes organisms whose chromosomes are not contained within a membrane-bound nucleus? Multiple choice question. progenotes prokaryotes archaeotes eukaryotes

Theodore Boveri Walter Sutton

Which two scientists independently proposed the chromosome theory of inheritance? Multiple select question. Walther Fleming Theodore Boveri Carl Nageli Walter Sutton August Weismann

X-linked

_______ genes are those that are physically located on the X chromosome. Multiple choice question. X-linked X-associated X-influenced X-limited