BT504 Midterm Current and Past Solved Papers Spring 2023

BT504 ( Genomics and Proteomics) · Midterm – Spring 2023 ( Current + Past ) · Solved By Bella · Write down main format of microarray technique? (3)

Cartridge-based Spotted Electronic Spotted Glass Slide Tissue Section Slide

Write different techniques of physical mapping?

Cytogenetic map A restriction map Fluorescent in situ hybridization Sequence tagged site (STS) map Nucleotide sequence map

What is prerequisite is determination of genome sequence?

Determination of entire genome sequence is a prerequisite to understand the complete biology of an organism.

Variation in bacterial genome?

Tremblaya princeps 140kb, 121 coding sequences Sorangium cellulosum 14000kb 11599 coding sequences

Position independent method?

No information about the location of the gene. Starting at the phenotype, determining which protein was involved and getting to gene through the protein. Starting from the approximate location of gene, to finding the gene itself, then translating it to learn about the protein and its function. Positional cloning or reverse genetics Mostly identifying and isolating the protein product of the gene. Such genes usually produce large amounts of well-known and well studied proteins. Two common methods used Gene-specific oligonucleotides Antibody Methods Recombination mapping and/or somatic cell mapping to defined the region of interest as tightly as possible. Chromosomes are inherited as intact units, so it is reasoned that the alleles of some pairs of genes will inherit together because they are on the same chromosome. Different approaches are used for identification of disease genes

3 Function of miRNA?

1. Involved in the post-transcriptional regulation of gene expression
2. Important in development
3. Metabolic regulation (miR-375 & insulin secretion)

Insertion sequence elements?

The simplest transposable elements Code only for the ability to transpose Prokaryotes Usually very small (< 1 Kb to 2 Kb) Flanked by inverted repeat sequences (IRs) Encode at least one gene that provides their own transposition functions Do not code for noticeable (phenotypic) traits Can cause mutations by transposition into genes

Difference between eukaryotic and prokaryotic DNA transcription?

Prokaryotes

Operons 27% of E. coli genes (Housekeeping genes not in operons) Simultaneous transcription and translation

Eukaryotes

No operons, but they still need to coordinate regulation. More kinds of control elements RNA processing Chromatin remodeling. Histones must be modified to loosen DNA.

Why Microarray needs to be scan, different colors and their result.

The scanner has a laser, a computer, and a camera. The laser causes the hybrid bonds to fluoresce. The camera records the images produced when the laser scans the plate. The computer allows to immediately view the results and it also stores the data. GREEN – the healthy sample hybridized more than the diseased sample. RED – the diseased/cancerous sample hybridized more than the nondiseased sample. YELLOW – both samples hybridized equally to the target DNA. BLACK – areas where neither sample hybridized to the target DNA.

Steps of genome analysis?

Genome sequence assembled Identify repetitive sequences – mask out Gene prediction – train a model for each genome. Look for EST and cDNA sequences Genome annotation Microarray analysis Metabolic pathways and regulation Protein 2D gel electrophoresis. Functional genomics Gene location/gene map Self-comparison of proteome Comparative genomics Identify clusters of functionally related genes Evolutionary modeling

D-loop of human mitochondrial genome? (5)

Circular, double stranded, 16.6 kb The two strands are notably different in base composition, leading to one strand being heavy (H strand) and the other light (L strand). Both strands encode genes, although more are on the H strand. A short region (1121 bp), the D loop is a DNA triple helix: two overlapping copies of the H strand.

Human mitochondrial genes contain no introns, although introns are found in the mitochondria of other groups (plants) 37 Genes 22 tRNAs 2 rRNAs 13 polypeptides tRNA: only 60 of the 64 codons code for amino acids.

Advantage of microarray? (5)

Define physical mapping? 3

Physical mapping is based on the direct analysis of DNA. Physical mapping places genes on the genomes in relation to distances measured in bp, kbp, and mbp.