Study Guide for Quiz 2 Biology

Anaphase 1

A double-stranded chromosome following replication attached by a centromere

spindle fibers

A number of threadlike filaments formed between poles of the cell during cell division

X chromosome

A sex chromosome; in human males only one is present and in females two are present

theory

After initial positive testing and observation the idea is called this.

law

After many experiments have verified the data by many different investigators over a period of time, the idea is called this.

autosome

Any pair of chromosomes other than the sex chromosome

oogenisis

Process of development of haploid female gametes

sex-chromosomes

The chromosomes which determine the sex of the individual

theory

The form of the hypothesis after it has been tested and found to be supported

spermatogenisis

The production of haploid male gametes by the male parent

Telophase 2

The stage of the second meiotic division when the cell divides into two cells with each being haploid

Metaphase 1

The stage on the first meiotic division when the homologous chromosomes move to opposite poles but the sister chromatids remain together.

Meiosis is the process that results in the production of the haploid number of chromosomes.

true

Nondisjunction can occur in autosomes and sex chromosomes.

true

The sister chromatids separate and migrate to opposite poles at Anaphase II

true

Twenty-three is the haploid number of chromosomes in man.

true

Meiosis consists of_______cell divisions with only one duplication of_______. This division results in______daughter cells, each with________set of chromosomes. This division represents a reduction in chromosomes; that is, the diploid chromosome number of the parent cells is reduced to the_______number of the daughter cells.

-2 -chromosomes -4 -1 -haploid

W.S. Sutton proposed that the_______are located on_______and these factors segregate during________ and the production of gametes.

-genetic factors -chromosomes -meiosis

Meiosis is associated with the:

-haploid number of chromosomes -gamete cells

If the trait for height is designated as T=tall how would this sex-linked trait be understood as X t Y?

-the "y" chromosome does not carry a gene for height -the male shown would be recessive(short)

As a result of nondisjunction, a female gamete may contain:

-two sex chromosomes -no sex chromosomes

In the male fruit fly, what sex chromosomes will be in his gametes and in what proportions?

1/2 X and 1/2 Y

How many chromosome pairs are in humans?

23

Anaphase 2

A condition where non-sister chromatid of homologous chromosomes exchange genes

hypothesis

A proposed explanation for an observation which has not been experimentally tested

Y chromosome

A sex chromosome found in males; influencing the degree of maleness

chromatid

A structure on the chromosome that holds a pair of chromatids together during replication

hypothesis

An educated guess to explain an observation.

diploid

Both members of a pair of chromosomes are present

tetrad

During metaphase I the two pairs of chromatids of the homologous pair of chromosomes comes together

nondisjunction

Failure of chromosomes to segregate during the formation of gametes

sex-linked

Genes which are carried on the X chromosome

Telophase 1

In the first meiotic division the cell divides into two cells

haploid

One member of a pair of homologous chromosomes is present, such as in a gamete

polar body

One of three small cells produced during oogenesis

linkage

The presence of different genes on the same chromosome

Prophase 1

The stage in the first meiotic division where the doubled chromosomes become visibl

crossing over

The stage in the first meiotic division where the homologous chromosomes line up as a pair

Metaphase 2

The stage in the second meiotic division where sister chromatids migrate to opposite poles

centromere

The stage in the second meiotic division where the chromatid pair lines up at the equator of the cell

All ova contain sex chromosomes corresponding to:

X

Somatic cells include:

all the cells of an organism except the gametes

Genes which are "linked" together:

are found on a particular chromosome

Since the X and Y chromosomes of humans are so different in the genes they carry, the reason men and women resemble each other in overall appearance is because most traits are on_________.

autosomes

The sex of the offspring is determined:

by which chromosome, the X or Y, the offspring receives from the male parent

A tetrad is a paired, duplicated chromosome during Metaphase II.

false

Duplication of chromosomes begins after Prophase I.

false

Each chromosome represents a single gene.

false

Gametes are associated with diploid chromosomes.

false

Nondisjunction is limited to fruit flies.

false

Oogenesis gives one large ovum and 3 small polar bodies, each being diploid. Spermatogenesis gives four equal sperm, each being haploid.

false

Somatic cells are haploid.

false

Finding an occasional vermillion-eyed female can be explained by the occurrence of an extra chromosome from the________for the trait.

female

If the male fruit fly produces a gamete carrying an X chromosome, what will the sex of the offspring be?

female

How many chromosome pairs are in Drosophila?

four

What promoted C.B.Bridges to research the phenomenon of nondisjunction?

irregular sex-linked traits

Indicate the correct designation of the paired sex chromosomes.

male: XY female: XX

C.B. Bridges made a major contribution to the chromosome theory by discovering the principle of_______ .

nondisjunction

The sex chromosome contains many genes, and the traits controlled by these genes are said to be__________.

sex linked

Traits which are controlled by the sex chromosomes are called_______inheritance.

sex-linked

The symbols for sex-linked traits are indicated as________on the X and Y chromosome symbol.

superscripts

What is meant by homologous chromosomes?

the genes allele's are found in matched chromosome pairs

What is expected concerning the sex chromosomes of sperm?

they are all equal numbers of "X" and "Y"

A homologous pair of chromosomes is the chromosomes which influence the same genetic traits.

true

A scientific law may be used to predict the outcome of experiments.

true

All members of each species have the same number of chromosomes.

true

Chromosomes are located in the nucleus of the cell.

true

Chromosomes other than sex chromosomes are autosomes.

true

Crossing over gives variations in genetic material by exchange of chromatic parts.

true

Crossing over occurs during tetrad formation.

true

Each chromosome usually contains multiple genes.

true

Experiments and observations verify scientific laws.

true

If you have a red-eyed female fly, and you want to find out if it is a carrier for the white-eye gene, you would have to cross it with a ________male.

white-eyed

If the F2 generation of red and white eyed flies were allowed to cross-breed, could a white-eyed female occur?

yes

chromosome theory

The behavior of chromosomes explains the inheritance of genes

law

Supported by the results on many experiments by a large number of investigations