BIO505T Final Term Subjective Guess Paper 2023

BIO-301 FINAL TERM- 100% · GUESS PAPER 2023 · Essentials of Genetics · BY SULMAN ALI · SUBJECTIVES · VNTR and its applications:

VNTR are short nucleotide sequences organized as a tandem repeats on genomes. Found on many chromosomes, Show variations in length between individuals.

Application: 1.DNA fingerprinting 2.genetic diversity 3. forensic mapping of genome 4. breeding pattern of wild and domesticated animals 5. paternity testing 6. Evolutionary research .

Procedure for western blotting:

The Western blotting procedure involves several steps. First, proteins are separated by size using gel electrophoresis. Then, the proteins are transferred onto a membrane. The membrane is blocked to prevent non-specific binding, and then incubated with a primary antibody that binds to the target protein. After washing, a secondary antibody is added that recognizes the primary antibody. Finally, the protein bands are visualized using a detection method such as chemiluminescence.

Effect of environment on allelic expression:

Allele expression is influenced by environmental conditions, as seen in arctic foxes, Himalayan rabbits, and Siamese cats. For instance, the ch allele in Siamese cats is impacted by temperatures above 33°C, causing inactivation of the tyrosinase enzyme, leading to reduced melanin pigment and resulting in their characteristic coat color patterns.

Explain trisomy and it’s Types

Trisomy is a type of polysomy in which there are three copies of a particular chromosome,instead of the normal two. Trisomy is a type of aneuploidy.

Types:

1. Trisomy 21 (Down syndrome): Caused by an extra copy of chromosome 21, leading to intellectual disabilities and distinct facial features.
2. Trisomy 18 (Edwards syndrome): Resulting from an extra chromosome 18, it causes severe developmental issues and organ abnormalities.
3. Trisomy 13 (Patau syndrome): Arising from an extra chromosome 13, it causes serious birth defects and often shortened lifespans.

Difference between Ring and Philadelphia chromosome:

1= A ring chromosome is a chromosome whose arms have fused together to form a ring. In humans it is denoted by small r and in drosophila it is denoted by capital R., 2= Philadelphia chromosome:- is a specific chromosomal abnormality that is related with chronic myelogenous leukemia(CML). Reciprocal translocation between chromosome 9 and chromosome 22 which is specifically designated.

Types of chromosome on the base of centromere location:

1. Metacentric: Centromere centrally located, resulting in equal arms.
2. Submetacentric: Centromere slightly off-center, leading to unequal arms.
3. Acrocentric: Centromere near one end, creating a longer and a shorter arm.
4. Telocentric: Centromere at the end, resulting in a single long arm.

Effects of point mutation.

Point mutations alter single DNA bases, affecting protein structure/function. Substitutions (missense, nonsense) change amino acids or stop codons, impacting gene expression and possibly causing disease or genetic diversity.

How giemsa stain work/ Define giemsa stain.

Geimsa stain is a type of stain used in microscopy to visualize and differentiate different types of cells, especially blood cells. It works by Giemsa stain binds to DNA and RNA, creating distinct bands on chromosomes, allowing for better visualization of cellular structures and identification of specific cell types.

RAPD,ALFP difference:

RAPD: A PCR-based technique used to amplify random segments of genomic DNA using single primers. The amplified products reveal polymorphisms between individuals. Generally less expensive and simpler, as it requires fewer primer pairs.

AFLP: A PCR-based method that selectively amplifies subsets of restriction enzyme-digested genomic DNA, creating a fingerprint of fragments that differ among individuals. Usually more expensive and complex, involving multiple primer pairs and enzyme digestion steps.

Write about the non.disjunction/ Caused by ?

Non-disjunction is a genetic event that can occur during cell division, specifically during the separation of chromosomes. It can be caused by various factors, including genetic abnormalities, environmental factors, and maternal age. Non-disjunction can lead to an abnormal number of chromosomes in the resulting cells, which can cause genetic disorders such as Down syndrome.

Erythrocytes lysis in RNA purification:

In RNA purification, erythrocyte lysis is a step where red blood cells are broken open to release their contents. This is usually done using a lysis buffer that disrupts the cell membranes and releases the RNA. The lysate is then processed further to purify the RNA of interest.

Linked and causative single polymorphism.

A linked single nucleotide polymorphism (SNP) is located near another genetic variant on the same chromosome, often inherited together. A causative SNP directly influences a trait or disease, demonstrating a functional relationship through its impact on gene expression or protein structure.

10 organism names with chromosomes:

1= Human: 46 chromosomes, 2= Mouse: 40 chromosomes, 3= Fruit Fly: 8 chromosomes, 4= Dog: 78 chromosomes, 5= Cat: 38 chromosomes, 6= Rice: 24 chromosomes, 7= Corn: 20 chromosomes, 8= chimpanzee :48 chromosomes, 9= Elephant: 56 chromosomes, 10= Tomato:

Downstream genetic mapping:

Downstream genetic mapping refers to the process of analyzing genetic data to identify and map specific genes or genetic markers that are associated with a particular trait or disease. This involves conducting statistical analyses, such as genome-wide association studies (GWAS), to identify regions of the genome that are linked to the trait of interest. This information can then be used to further investigate the underlying genetic mechanisms and potential therapeutic targets.

Patterns of genetic disorders:

Patterns of genetic disorders refer to recognizable ways in which genetic conditions are inherited within families. These include:

1. AUTOSOMAL DOMINANT: Affected individuals are heterozygote. One allele is mutated, while other one is normal.
2. AUTOSOMAL RECESSIVE: Homozygous, when both alleles of the gene are mutated.
3. X-LINKED RECESSIVE: Mutated alleles are present on either of the sex
4. MULTIFACTORIAL: Genes and environment both contribute.

Hot Start PCR:

enhances specificity. It involves initially deactivating the DNA polymerase enzyme at lower temperatures. This prevents early DNA replication until the reaction is heated to the optimal temperature, reducing false products. Hot Start PCR is preferred over conventional PCR to improve target amplification accuracy. It's useful for complex DNA samples with multiple similar sequences, minimizing unwanted amplification. Hot Start PCR is crucial in applications like genotyping, DNA sequencing, and analyzing low-quality samples where specificity is crucial for reliable results.

Diagnostic test for genetic disorder:

A diagnostic test for a genetic disorder usually involves analyzing a person's DNA to detect specific mutations or variations associated with the disorder. These tests can include techniques like PCR, DNA sequencing, and microarray analysis. Keep in mind that specific tests depend on the suspected disorder. It's important to consult a medical professional for accurate guidance and testing recommendations.

Tests:

PCR-Based Tests, DNA Sequencing Fluorescence , In Situ Hybridization (FISH), Microarray Analysis, Southern Blotting, Northern Blotting, Western Blotting, Karyotyping, Cytogenetic Analysis, Genomic DNA Methylation Analysis, Whole Exome Sequencing (WES).

Applications of PCR or Uses of PCR:

PCR has applications in DNA amplification, 1.Genetic testing 2 forensics, medical diagnostics,

3. Environmental studies 4.Evolutionary studies 5.food safety 6 .Archaeology, and anthropology.

Define interphase and cell cycle stages 3

Interphase: is the stage in the cell cycle where the cell prepares for division. It is divided into three phases: G1 (Gap 1), S (Synthesis), and G2 (Gap 2). During interphase, the cell grows, carries out its normal functions, and replicates its DNA in the S phase. The cell cycle stages include interphase and mitosis (or meiosis in reproductive cells).

Principle of pCR:

The thermocycler works on the principle of Peltier effect, which raises and lowers the temperature of the block in a pre-programmed manner.

The principle of PCR (Polymerase Chain Reaction) involves the enzymatic amplification of a specific DNA sequence. It consists of repeated cycles of heating (denaturation), cooling (annealing), and DNA synthesis (extension). This process uses a DNA template, DNA primers,