Question

BLAST results will indicate the percentage of genome comparison among known sequences as well as predicted sequences. A predicted sequence can best be characterized as a(n)

	a.	computational analysis showing similarity to a known protein
	b.	expected similarity to a species due to evolutionary relationship
	c.	a sequence found in all species of a particular genus
	d.	the educated computerized “guess” based on the original programmer’s data input

All cancers arise as a result of changes in the DNA sequence of the genomes of cancer cells. Gene expression assays may be helpful in showing the progression of the cancer phenotype by identifying the driver mutations which are:

	a.	mutations that develop as the cancer becomes invasive
	b.	activating and loss of function mutations
	c.	mutations that initiated the cancer
	d.	mutations that make the cancer chemotherapy resistant

Answer 1

Ans.1. The most reliable approache to characterized the unknown/ predicted sequence is a database search of the TRANSLATED Seuence (protein coding ORF) for homologs / similarilty and finding coding potential of the ORF using BLAST etc.

Thus correct option is (a): Computational analysis showing similarity to a known protein (in database).

Ans. 2. A driver mutation is an alteration in DNA that gives a cancer cell advantage to grow neoplastic / cancerous cell by enhancing division or preventing cell death (oncogene) or by inactivating tumor-suppressor genes.

Cancer have initiation and progression / promotion stages. Loss / gain function mutation initiate tumber. Tumor progression means  phenotypic changes in an already-formed neoplastic lesion/ cancer. Invasive tumors do invade the basement membrane and its an example of cancer progression.

Thus mutations that develop as the cancer becomes invasive show the progression of the cancer phenotype.

Correct option is (a).