Cell Biology - Interphase Nucleus Part II

These flashcards cover key concepts, definitions, and specific conditions related to cell biology, chromosome structure, and genetic abnormalities as discussed in the lecture.

What is a karyotype?

A karyotype is the complete set of chromosomes conveniently organized that defines a species.

Who first observed the metaphasic chromosome?

Hoffmeister in 1848.

What structural feature is crucial for chromosome segregation during mitosis?

The centromere.

What are cohesins responsible for during mitosis?

Cohesins maintain sister chromatids together until proper separation.

What is the main function of condensins in cell biology?

Condensins form nucleoprotein complexes that allow for chromosome condensation.

Define chromomeres.

Chromomeres are accumulations of dense chromatin, localized thickenings found along chromosomes during early nuclear division.

What does FISH stand for in molecular cytogenetics?

FISH stands for Fluorescent In Situ Hybridization.

What is the cause of Down syndrome?

Down syndrome occurs when there is an extra full or partial copy of chromosome 21, usually due to nondisjunction.

What does aneuploidy refer to?

Aneuploidy refers to an abnormal number of chromosomes, such as monosomy or trisomy.

What genetic condition is caused by monosomy of the sex chromosomes?

Turner syndrome.

What is the main characteristic of Klinefelter syndrome?

Klinefelter syndrome is characterized by the presence of an extra X chromosome in males.

What is the phenomenon called when a chromosome fragment is lost?

Deletion.

What mutation occurs when a fragment of a chromosome is inverted?

Inversion.

Describe the relationship between maternal age and the risk for Down syndrome.

As maternal age increases, the risk for having a child with Down syndrome also increases.

What is the most common inherited form of mental retardation?

X-fragile syndrome.

What type of chromosomal abnormality is associated with Chronic Myelogenous Leukemia (CML)?

Translocation involving chromosomes 9 and 22, specifically the Philadelphia chromosome.