Physiology Exam 1

Front

What is chromatin?

Back

Chromatin is DNA wrapped around a histone octamer, forming a complex that packages DNA into a compact structure.

Front

What are the potential chromosomal abnormalities resulting from lack of Shelterin complex formation?

Back

Unstable telomeres, chromosome fusions, chromosome degradation, dicentric chromosomes.

Front

How do insulators influence gene expression?

Back

Insulators prevent the association of activators with core promoters, thereby regulating gene expression.

Front

What disease state in dogs is characterized by increased incidence of dicentric and metacentric chromosomes?

Back

Osteosarcoma.

Front

What is the effect of a nonsense mutation in a gene encoding for a histone acetyltransferase?

Back

It leads to decreased regions of euchromatin throughout the genome, causing lower levels of gene expression.

Front

Define histone acetyltransferase (HAT).

Back

HAT is an enzyme that adds acetyl groups to histones, leading to a more open chromatin structure and increased gene expression.

Front

What is the role of telomeres in chromosome stability?

Back

Telomeres protect the ends of chromosomes from degradation and prevent them from fusing with other chromosomes.

Front

What are dicentric chromosomes?

Back

Dicentric chromosomes are chromosomes that have two centromeres, which can lead to instability during cell division.

Front

Explain the concept of euchromatin.

Back

Euchromatin is a less condensed form of chromatin that is actively involved in transcription and gene expression.

Front

What is heterochromatin?

Back

Heterochromatin is a tightly packed form of DNA that is generally transcriptionally inactive.