Search Previous Year Questions

The correct answer is Jaundice

Concept:

• Aminocentesis is a medical procedure used primarily in prenatal diagnosis to obtain amniotic fluid, which contains fetal cells and various chemicals produced by the baby.
• This procedure is commonly used to diagnose chromosomal abnormalities and fetal infections.
• Common conditions diagnosed through amniocentesis include Down syndrome, Klinefelter syndrome, Turner syndrome, and other genetic disorders.

Explanation:

• Down Syndrome: This is a genetic disorder caused by the presence of an extra chromosome 21. Amniocentesis can detect this condition through chromosomal analysis of the fetal cells in the amniotic fluid.
• Klinefelter Syndrome: This is a genetic condition in males caused by an extra X chromosome (47,XXY). Amniocentesis can identify this syndrome by analyzing the chromosomes of the fetal cells.
• Turner Syndrome: This is a condition affecting females where one of the X chromosomes is missing or partially missing (45,X). Amniocentesis can detect Turner syndrome through chromosomal analysis.
• Jaundice: This is a medical condition characterized by yellowing of the skin and eyes due to elevated levels of bilirubin in the blood. It is not related to genetic abnormalities or chromosomal analysis, and hence, it is not detected through amniocentesis.

The correct answer is All of the above

Explanation:

• Taxonomy is the science of defining and naming groups of biological organisms based on shared characteristics. It involves a systematic approach to classify and organize living organisms into a structured framework.
• The primary objectives of taxonomy are to identify, name, and classify organisms. These three processes are interconnected and form the basis of taxonomy.
• Identification: This is the process of determining and recognizing an organism as a distinct entity. It involves observing and comparing the characteristics of an organism to known species to ascertain its identity. Identification helps in distinguishing one organism from another.
• Nomenclature: This refers to the assigning of names to organisms based on a standardized system. The International Code of Zoological Nomenclature (ICZN) and the International Code of Botanical Nomenclature (ICBN) provide guidelines for naming animals and plants, respectively. Proper nomenclature ensures that each organism has a unique and universally accepted name.
• Classification: This is the process of organizing organisms into hierarchical groups based on their evolutionary relationships and shared characteristics. Classification involves grouping organisms into categories such as kingdom, phylum, class, order, family, genus, and species.

The correct answer is Coelom

Explanation:

• During the embryonic development of triploblastic animals, three primary germ layers are formed: the ectoderm, mesoderm, and endoderm.
• The coelom is a fluid-filled cavity that lies within the mesoderm and is lined by mesodermal tissue.
• This cavity allows for the development and expansion of internal organs and provides a space for them to move independently of the body wall.

Fig: Diagrammatic sectional view of (a) Coelomate (b) Pseudocoelomate (c) Acoelomate

Other Options:

• Pseudocoelom: A pseudocoelom is a body cavity that is not fully lined by mesodermal tissue. Instead, it is partially lined by tissue derived from the mesoderm and endoderm. This type of body cavity is found in pseudocoelomate animals, such as roundworms (Nematoda). It does not provide as much structural support or organ development potential as a true coelom.
• Acoelom: Acoelomate animals lack a body cavity altogether. Their internal organs are embedded directly within solid mesodermal tissue. This condition is seen in simpler animals such as flatworms (Platyhelminthes). The absence of a coelom limits the complexity and size of these organisms.

The correct answer is All of these

Concept:

• DNA, or deoxyribonucleic acid, is the molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses.
• The DNA chain is composed of nucleotides, each containing a phosphate group, a sugar molecule (deoxyribose), and a nitrogenous base.

Explanation:

• Phosphodiester Bond:

• This type of bond forms the backbone of the DNA strand.

• It connects the 5'-phosphate group of one nucleotide to the 3'-hydroxyl group of another nucleotide, creating a strong covalent linkage.

• Hydrogen Bond:

• DNA is a double-stranded helical molecule. The two strands are complementary and anti-parallel.

• The hydrogen bonds between the paired bases (A-T and G-C), repeated along the length of the DNA double helix, hold the two strands together in the double helix.

• There are two hydrogen bonds between Adenine and Thymine base pair, whereas, there are three hydrogen bonds between Guanine and Cytosine base pair.

• Glycosidic Bond: This type of bond connects the nitrogenous base to the sugar molecule (deoxyribose) in a nucleotide.

The correct answer is Centromere division

Explanation:

Metaphase is a stage of mitosis in the eukaryotic cell cycle where chromosomes align in the middle of the cell before being separated into each of the two daughter cells. During metaphase, the chromosomes become highly condensed, making them easier to observe under a microscope.

• Spindle fibers are attached to small disc-shaped structures at the surface of centromeres called kinetochores: This is a correct statement. During metaphase, the spindle fibers attach to the kinetochores, which are protein complexes assembled on the centromere of each chromosome.
• The plane of alignment of the homologous pair of chromosomes at metaphase is referred to as the metaphase plate: This is a correct statement. The metaphase plate is an imaginary plane that is equidistant from the two centrosome poles and is where chromosomes align during metaphase.
• Chromosomes appear to be made up of two sister chromatids: This is a correct statement. Each chromosome during metaphase consists of two sister chromatids, which are identical copies of the original chromosome, connected by a centromere.
• Centromere division: This is the incorrect statement. Centromere division, or the separation of sister chromatids, occurs during anaphase, not during metaphase. During metaphase, the chromosomes are merely aligned at the metaphase plate.

The correct answer is Unicellular

Explanation:

• Trichomes are hair-like outgrowths of the epidermis in plants. They can be found on stems, leaves, and reproductive organs.
• These structures serve various functions such as protection against herbivores, reducing water loss, and sometimes aiding in seed dispersal.
• Trichomes are generally multicellular, consisting of multiple cells forming the hair-like structures.
• Trichomes originate from the epidermal tissue system, which is the outermost layer of cells in plants. This tissue system plays a crucial role in protection and interaction with the environment.

The correct answer is Actin and myosin filaments do not shorten they only pass each other.

Concept:

• The sliding filament theory is a widely accepted explanation for how muscles contract to produce force. It was first proposed by scientists Huxley and Hanson in the 1950s.
• According to this theory, muscle contraction occurs when the thin actin filaments slide past the thick myosin filaments, causing the sarcomere (the functional unit of a muscle fiber) to shorten.
• During contraction, the myosin heads bind to actin, forming cross-bridges, and then pull the actin filaments toward the center of the sarcomere through a series of power strokes.
• This sliding of filaments does not involve any shortening of the filaments themselves; instead, it is the relative movement of the actin and myosin filaments that leads to muscle contraction.

Explanation:

Actin and myosin filaments do not shorten; they only pass each other.

• This is the correct answer. The sliding filament theory describes that during muscle contraction, the actin and myosin filaments slide past one another without changing their length, leading to the shortening of the sarcomere and thus the muscle itself.

Other Options:

• Actin and myosin filaments shorten and slide past each other.
• This is incorrect because the actin and myosin filaments do not shorten during muscle contraction. They remain the same length but slide past each other to create the shortening of the muscle.
• When myofilaments slide past each other, shortening of actin filaments occur.
• This is incorrect because actin filaments do not shorten. The sliding filament theory specifies that it is the sliding of the filaments, not their shortening, that leads to muscle contraction.
• When myofilaments slide past each other, shortening of myosin filaments occur.
• This is incorrect because myosin filaments do not shorten. Similar to actin, the myosin filaments remain the same length and it is their sliding action relative to the actin filaments that causes contraction.

The correct answer is 500 ml

Explanation:

• Tidal volume (TV) is the volume of air moved into or out of the lungs during normal, quiet breathing.
• Tidal Volume (TV) is the Volume of air inspired or expired during normal respiration. It is approx. 500 mL., i.e., a healthy man can inspire or expire approximately 6000 to 8000 mL of air per minute.

 Additional Information

• Inspiratory capacity (IC)  - Total volume of air a person can inspire after a normal expiration. This includes tidal volume and inspiratory reserve volume (TV+IRV).
• Expiratory Capacity (EC): Total volume of air a person can expire after a normal inspiration. This includes tidal volume and expiratory reserve volume (TV+ERV).
• Vital Capacity (VC) - The maximum volume of air a person can breathe in after a forced expiration. This includes ERV, TV and IRV
• Residual Volume (RV) - Volume of air remaining in the lungs even after a forcible expiration. This averages 1100 mL to 1200 mL.
• Functional Residual Capacity (FRC): Volume of air that will remain in the lungs after a normal expiration. This includes ERV+RV.

The correct answer is A-(ii), B-(iv), C-(i), D-(iii).

Explanation:

• A. PCR - Kary Mullis (ii):
• Polymerase Chain Reaction (PCR) is a technique used to amplify a segment of DNA, producing millions of copies of a particular DNA sequence.
• Kary Mullis developed the PCR technique in 1983, which revolutionized molecular biology and genetic research.
• B. DNA Fingerprinting - Alec Jeffreys (iv):
• DNA fingerprinting is a method used to identify individuals based on their unique DNA profiles.
• Alec Jeffreys developed DNA fingerprinting in 1984, which has applications in forensic science, paternity testing, and genetic studies.
• C. DNA as genetic material - Hershey & Chase (i):
• In 1952, Alfred Hershey and Martha Chase conducted experiments using bacteriophages to demonstrate that DNA is the genetic material, not protein.
• D. Semiconservative replication - Meselson & Stahl (iii):
• Matthew Meselson and Franklin Stahl conducted experiments in 1958 that demonstrated DNA replication is semiconservative. This means that each new DNA molecule consists of one old strand and one new strand.

The correct answer is A-(ii), B-(i), C-(iv), D-(iii)

Explanation:

• Aspergillus niger: This fungus is widely used in the industrial production of citric acid. It is known for its high yield of citric acid, which is used in food, pharmaceuticals, and other industries.
• Clostridium butylicum: This bacterium is known for producing butyric acid, which is used in the synthesis of various chemicals and as a flavoring agent.
• Acetobacter aceti: This bacterium is used in the production of acetic acid, which is commonly known as vinegar. It is essential in food preservation and as a condiment.
• Lactobacillus: This genus of bacteria is involved in the production of lactic acid, which is used in the dairy industry, pharmaceuticals, and as a preservative. Hence, D-(iii) is correct.