Quiz 2: Chromosome Basis of Heredity

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

Anaphase I

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

Anaphase II

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

Metaphase II

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

True

Crossing over occurs during tetrad formation.

True

W.S. Sutton proposed that the ___________ are located on _____________ and these factors segregate during _____________ and the production of gametes.

genetic factors, chromosomes, meiosis

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

haploid

Meiosis is associated with the:

haploid number of chromosomes, gamete cells

The presence of different genes on the same chromosome

linkage

Process of development of haploid female gametes

oogenesis

Genes which are carried on the X chromosome

sex-linked

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

1/2 Y and 1/2 X

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

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

False

Somatic cells are haploid.

False

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

False.

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

False.

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

Metaphase I

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

All ova contain sex chromosomes corresponding to:

X

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

X chromosome

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

Y chromosome

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

autosome[s]

Any pair of chromosomes other than the sex chromosome

autosomes

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

centromere

A double-stranded chromosome following replication attached by a centromere

chromatid

The behavior of chromosomes explains the inheritance of genes

chromosome theory

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

crossing over

Both members of a pair of chromosomes are present

diploid

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

female

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

hypothesis

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

irregular sex linked traits

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

law

Failure of chromosomes to segregate during the formation of gametes

nondisjunction

One of three small cells produced during oogenesis

polar body

The chromosomes which determine the sex of the individual

sex-chromosomes

The production of haploid male gametes by the male parent

spermatogenesis

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

spindle fibers

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

tetrad

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, and the male shown would be recessive.

What is meant by homologous chromosomes?

the gene's alleles are found in matched chromosome pairs

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

theory

What is expected concerning the sex chromosomes of sperm?

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

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

two sex chromosomes or no sex chromosomes.

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

yes

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

Prophase I

In the first meiotic division the cell divides into two cells

Telophase I

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

Telophase II