The Chromosomal Basis of Inheritance

Both chromosomes and Mendel’s proposed hereditary factors (genes) are present in __ in diploid cells.

pairs

Homologous chromosomes __ and alleles segregate during the process of meiosis.

separate

Fertilization restores the __ condition for both chromosomes and genes.

paired

Specific genes have specific __ along chromosomes.

loci

It is the chromosomes that undergo __ and independent assortment.

segregation

The behavior of homologous chromosomes during __ accounts for the Law of Segregation.

Anaphase I

The behavior of non-homologous chromosomes during __ accounts for the Law of Independent Assortment.

Metaphase I

Eggs always carry one __ chromosome.

X

The XY individuals will present whichever __ is inherited.

allele

More XY individuals have __ recessive disorders.

X-linked

In XX individuals, one X-chromosome is methylated and shut down, forming a __.

Barr Body

XX individuals exhibit a __ of X traits.

mosaic

Members of a pair of homologous chromosomes do not move apart separately during __.

Meiosis I

In a nondisjunction in meiosis I, all 4 gametes have an __.

error

In nondisjunction in meiosis II, 2 of the 4 gametes are normal and __ have an error.

2

Aneuploidy refers to gametes with an abnormal number of a particular __.

chromosome

A monosomic zygote is __ one chromosome (2n-1).

missing

A trisomic zygote has __ chromosome (2n+1).

an extra

Polyploidy refers to more than __ complete chromosome sets in all somatic cells.

two

Triploidy is represented as __.

3n

Tetraploidy is represented as __.

4n

Certain genes are methylated depending on whether they are in an __ or a _.

egg; sperm

Once the zygote is created, it will erase all the __.

imprints

In humans, the egg is responsible for the __ lineage.

mitochondrial

In plants, mitochondria is often inherited through the __ parent.

male

In plants, chloroplast is inherited through the __ parent.

female

The segregation of chromosomes during anaphase I explains the __ of inheritance.

law