BIO505T Midterm Subjective Guess Paper 2023 by VUBuddy

BIO-301 SUBJECTIVE MIDTERM- · 100% GUESS PAPER 2023 · Essentials of Genetics · BY SULMAN ALI · SUBJECTIVES

Note on oligonucleotide in mapping of disease gene.

Oligonucleotide is a short DNA sequence that can be used in mapping disease genes. These sequences can be used as probes to detect the presence of disease genes in a sample. Oligonucleotide probes can be synthesized to match the sequence of a specific gene, and then used to detect the presence of that gene in a sample. This technique is useful in identifying the genetic basis of diseases.

Genetic and environmental causes of variation.

Genetic causes of variation include mutations and genetic recombination, difference in DNA sequence that can affect traits such as eye color, hair color, and susceptibility to diseases.

Environmental variation: Differences in traits that are caused by environmental factors such as nutrition, exposure to toxins, and access to healthcare. while environmental causes of variation include exposure to different environmental factors such as temperature, light, and diet.

Spermatogesis and oogenesis.

Spermatogenesis is the process of producing sperm, while oogenesis is the process of producing eggs. Spermatogenesis occurs in the testes of males, while oogenesis occurs in the ovaries of females.

Difference between prokaryotes and eukaryotes.

Prokaryotes are unicellular organisms that do not have a nucleus or membrane-bound organelles, while eukaryotes are multicellular organisms that have a nucleus and membranebound organelles.

Common Epigenetics regulated phenomena:

Common epigenetic phenomena include DNA methylation, histone modification, and noncoding RNA regulation.

CEN DNA.

CEN DNA is a sequence of DNA found in eukaryotic chromosomes that is responsible for attaching the chromosomes to spindle fibers during cell division.

CAUSES OF EPIGENETICS:

3= DNA methylation, 2= Histone modification, 3= miRNAs

Number of chromosomes in chicken, house fly, gold fish?

Chicken has =78 chromosomes, house fly has= 12 chromosomes, and goldfish has =94 chromosomes.

Enlist the genes in drosophila of linkage mapping.

The genes in Drosophila of linkage mapping include white, yellow, brown, and ebony.

Explain the conformation of DNA.

The conformation of DNA is a double helix structure composed of nucleotides. The nucleotides consist of a sugar molecule, a phosphate group, and a nitrogenous base. The nitrogenous bases include adenine, thymine, cytosine, and guanine. Adenine pairs with thymine and cytosine pairs with guanine through hydrogen bonds. The double helix structure of DNA is stabilized by hydrogen bonds between the base pairs and the hydrophobic interactions between the stacked bases.

Note on staining procedures.

Staining procedures are used in microscopy to enhance the contrast and visibility of biological specimens. Different types of stains can be used to highlight different structures within a sample. For example, hematoxylin and eosin stains are commonly used to differentiate between different types of cells and tissues. Gram staining is used to differentiate between different types of bacteria. Staining procedures can also be used to detect the presence of specific molecules within a sample, such as antibodies or enzyme.

What type of variation occur in human:

1= Variations in skin color 2= Variation in hair color 3= Variation in hair curliness 4= Variation in eye color 5= Variation in sex.

Difference btw continuous and discontinuous variation.

Discontinuous variation entirely genetically controlled. They cannot be altered by external condition. blood group, color blind and dwarfism are genetically controlled.

Continuous variation describe the situation in which there are many intermediate between the extremes. Example shade of hair color between the black and blond.

Define Division of meiosis:

Meiosis is a cellular division process that produces haploid cells with half the chromosome number of the parent cell. It involves two rounds of division, resulting in four genetically diverse daughter cells.

What is meaning of exception of mendelian inheritance?

The exceptions to Mendelian inheritance are patterns of inheritance that do not follow the rules of dominance, segregation, and independent assortment described by Gregor Mendel. Some examples of exceptions to Mendelian inheritance include: 1= Incomplete dominance: 2= Codominance: 3= Multiple alleles: 4= Polygenic inheritance: 5= Epistasis:

Define leading strand, Lagging strand, okazaki fragments. Gyrase and sister chromatids

In DNA replication, the leading strand is synthesized continuously in the 5' to 3' direction, following the replication fork, while the lagging strand is synthesized discontinuously in short fragments called Okazaki fragments. Okazaki fragments are later joined by DNA ligase to form a continuous strand. Gyrase is an enzyme that helps relieve the tension caused by DNA unwinding during replication. Sister chromatids are two identical copies of a chromosome joined together at the centromere, formed during DNA replication, and are separated during cell division.

Write note on genome imprinting:

Genomic imprinting is an epigenetic mechanism where certain genes are expressed differently based on their parental origin. Imprinted genes are marked with epigenetic tags, such as DNA methylation, during gamete formation. This leads to parent-specific gene expression patterns that can influence embryonic development, growth, and disease susceptibility. Imprinting disorders can result from abnormal gene expression patterns and have significant implications for human health.

What happens in anaphase:

In anaphase, the sister chromatids of each chromosome separate and move towards opposite poles of the cell. Microtubules attached to the centromeres shorten, pulling the chromatids apart and ensuring equal distribution of genetic material.

Role of positive and negative apistasis:

Positive epistasis occurs when the effect of one gene enhances the effect of another gene, leading to a more pronounced phenotype. Negative epistasis, on the other hand, occurs when the effect of one gene suppresses or diminishes the effect of another gene, resulting in a reduced phenotype.

Define nucleotide, nucleoside, purine, and pyrimidine.

A nucleotide is a building block of nucleic acids (DNA and RNA) consisting of three components: a sugar (ribose or deoxyribose), a phosphate group, and a nitrogenous base. A nucleoside is a similar structure, but lacks the phosphate group. Purines (adenine and guanine) and pyrimidines (cytosine, thymine, and uracil) are the two types of nitrogenous bases. Purines have a double-ring structure, while pyrimidines have a single-ring structure. Nucleotides combine to form the backbone of DNA and RNA strands.

Name five mapping technique.

1= Genetic mapping 2= Physical mapping 3= Radiation hybrid mapping 4= Comparative mapping 5= Restriction fragment length polymorphism (RFLP) mapping.

Define Classical and reverse genetics:

Classical genetics refers to the study of phenotypic traits and inheritance patterns to understand gene function. It involves crossing organisms with specific traits to analyze their inheritance. Reverse genetics is a more modern approach to studying genetics that involves starting with a known gene and then determining its function by creating mutations in the gene and observing the resulting phenotype. This approach is useful for studying the function of specific genes and for identifying potential drug targets.

Define Interphase, particulate and blending hypothesis, mono allelic, diallelic and poly allelic.

Interphase is the longest phase of the cell cycle, where the cell grows, carries out metabolic activities, and duplicates its DNA in preparation for cell division.

The particulate hypothesis suggests that hereditary traits are discrete particles (genes) passed from parents to offspring, while the blending hypothesis proposes that traits blend in offspring.

Monoallelic refers to a gene having only one active allele, while diallelic indicates the presence of two alleles. Polymorphism occurs when a gene has multiple alleles in a population, resulting in genetic diversity.

Describe the Prophase 1:

Prophase I is the first phase of meiosis I. During this stage, chromatin condenses into chromosomes, homologous chromosomes pair up in a process called synapsis, and crossing over