Chromosomal Inheritance+ Pedigrees

What are the two types of chromosomes in humans?

Sex chromosomes (X and Y) and autosomes (44 chromosomes or 22 pairs).

What is nondisjunction?

The failure of homologous chromosomes or sister chromatids to separate properly during meiosis.

What does euploid mean?

An organism that contains 2n chromosomes, where 'Eu' means true.

What is aneuploidy?

An organism that contains (2n-1) or (2n+1) chromosomes, meaning it has either one less or one more chromosome than normal.

What is monosomy?

A condition in which there is a missing copy of a chromosome (2n-1).

What is trisomy?

A condition in which there is a third copy of a chromosome (2n+1).

What does a pedigree represent?

A family tree showing the traits of parents and children across generations.

In an autosomal recessive pedigree, what genotypes are unaffected individuals?

AA or Aa genotypes are unaffected; Aa individuals are carriers.

What does it indicate if a trait seems to skip a generation in a pedigree?

That the trait is likely inherited in an autosomal recessive manner.

In an autosomal dominant pedigree, what genotypes are affected individuals?

AA or Aa genotypes are affected; unaffected individuals are aa.

In X-linked recessive pedigrees, which individuals are typically affected?

Males are more commonly affected, and there will be no heterozygous males.

What is the typical inheritance pattern for mitochondrial DNA?

Traits are inherited from the mother only, and either all or none of the offspring are affected.

In X-linked dominant pedigrees, what indicates that a trait will be passed on?

Kids with the trait must have at least one affected parent, usually affecting daughters of affected fathers.

What does 'affected mother – affected sons' imply in X-linked recessive inheritance?

Affected mothers will pass on the affected allele to all of their sons.

In pedigrees, what do dark circles and squares represent?

Shaded circles represent affected females, and shaded squares represent affected males.

What is the main distinction of mitochondrial inheritance in a pedigree?

It will not be passed from father to offspring, highlighting maternal lineage.