In the mechanism of a dialyser (artificial kidney), the dialysing fluid is essentially identical to plasma except it lacks:
- Essential electrolytes
- Glucose and salts
- Nitrogenous wastes
- Plasma proteins
Explanation: The dialysing fluid has the same osmotic pressure as plasma but lacks urea and other metabolic wastes, allowing them to diffuse out of the blood.
In human anatomy, the 'Tricuspid Valve' is situated between which two chambers?
- Left side
- Right side
- Both atria
- Both ventricles
Explanation: The tricuspid valve is located between the right atrium and the right ventricle to prevent the backflow of deoxygenated blood.
Which of the following is a Bryophyte used to prevent soil erosion by forming dense mats?
- Marchantia
- Funaria
- Both above
- Neither above
Explanation: Mosses (like Funaria) and liverworts (like Marchantia) form dense mats on soil, which reduce the impact of falling rain and prevent soil erosion.
The term 'T-DNA' in the context of plant transformation stands for:
- Template DNA
- Total DNA
- Transfer DNA
- Terminal DNA
Explanation: T-DNA is the segment of the Ti-plasmid that is transferred from the Agrobacterium into the host plant's genome.
Flowers that do not open at all, ensuring self-pollination even in the absence of pollinators, are called:
- Cleistogamous
- Hydrophilous
- Chasmogamous
- Anemophilous
Explanation: Cleistogamous flowers are invariably autogamous as there is no chance of cross-pollen landing on the stigma. They produce assured seed-set even without pollinators.
Which of the following plants utilizes leaf tendrils (modifications of leaflets) for climbing?
- Cucumber
- Grape vine
- Wild pea
- Watermelon
Explanation: In Sweet pea or Wild pea, the leaves or leaflets are modified into tendrils for climbing, unlike Gourds where the stem is modified.
Which digestive juice contains no enzymes but is vital for the emulsification of fats?
- Gastric juice
- Intestinal juice
- Bile juice
- Pancreatic juice
Explanation: Bile, produced by the liver, contains bile salts but no enzymes. It is essential for emulsifying large fat globules into small micelles.
Which substance in the alveoli prevents them from collapsing by reducing surface tension?
- Mucus
- Carbonic acid
- Plasma protein
- Surfactant
Explanation: Pulmonary surfactant (mainly lecithin) lowers surface tension in the alveoli, preventing collapse (atelectasis) during expiration.
Which of the following physical agents is classified as an ionizing carcinogen?
- Infrared rays
- X-rays
- UV rays
- Visible light
Explanation: Ionizing radiations like X-rays and gamma rays cause DNA damage and neoplastic transformation. UV rays are non-ionizing carcinogens.
The 'First Mammals' appeared on Earth during which geological period?
- Tertiary
- Cretaceous
- Jurassic
- Triassic
Explanation: While dinosaurs dominated the Jurassic, the earliest shrew-like mammals actually appeared in the late Triassic period.
Which of the following makes up the diffusion membrane in the lungs?
- Single layer epithelium
- Triple layer membrane
- Thick fibrous tissue
- Ciliated columnar cells
Explanation: It consists of the squamous epithelium of alveoli, the endothelium of capillaries, and the basement substance between them.
Regarding 'Monosporic' development of the embryo sac, it implies that the embryo sac develops from:
- Four megaspores
- Two megaspores
- Microspore mother cell
- Single megaspore
Explanation: In a majority of flowering plants, one of the megaspores is functional while the other three degenerate. Only the functional megaspore develops into the female gametophyte.
Regarding the transport of nutrients in plants, the direction of flow in the Phloem is typically:
- Unidirectional only
- Strictly upward
- Strictly downward
- Bi-directional
Explanation: Unlike xylem, which conducts water and minerals upward (unidirectional), phloem conducts food from leaves to storage organs and growing parts in both upward and downward directions.
The 'Glenoid Cavity' provides an articulation point for which specific bone?
- Tibia
- Femur
- Humerus
- Radius
Explanation: The glenoid cavity is a depression in the scapula that articulates with the head of the humerus to form the shoulder joint.
The 'Yellow Spot' is another common name for which retinal area?
- Ora serrata
- Optic disc
- Macula lutea
- Vitreous body
Explanation: The macula lutea contains a yellow pigment (xanthophyll), earning it the name 'yellow spot'.
The biological product 'Alpha-1-antitrypsin' produced via transgenic animals is used to treat:
- Phenylketonuria
- Emphysema
- Cystic fibrosis
- Albinism
Explanation: Alpha-1-antitrypsin is a protein used to treat emphysema; similar attempts are being made for the treatment of PKU and cystic fibrosis.
Which extant class represents jawless, mostly ectoparasitic marine vertebrates?
- Chondrichthyes
- Osteichthyes
- Amphibia
- Cyclostomata
Explanation: Class Cyclostomata includes jawless fishes (Agnatha) like lampreys and hagfishes, which are ectoparasites on some fishes.
The 'Antineuritic factor' was the original name given to which vitamin?
- Vitamin B12
- Vitamin C
- Vitamin B6
- Vitamin B1
Explanation: Vitamin B1 (Thiamine) was called antineuritic because it prevents the nerve inflammation associated with Beriberi.
The efficiency of aerobic respiration in terms of energy captured from glucose is approximately:
- Nearly 90%
- Less than 10%
- Roughly 40%
- Exactly 100%
Explanation: Aerobic respiration captures about 38-40% of the energy available in glucose as ATP; the remaining 60% is lost as heat, which helps maintain body temperature.
A 'Cataract' is a condition where the lens of the eye becomes:
- Highly transparent
- Opaque or cloudy
- Too thin
- Excessively small
Explanation: Cataracts involve the protein buildup in the lens that makes it cloudy, obstructing light and causing blurred vision.
The 'Scala Media' of the cochlea is uniquely filled with which fluid?
- Endolymph
- Perilymph
- Plasma
- Synovial fluid
Explanation: While the scala vestibuli and scala tympani contain perilymph, the scala media contains endolymph.
In the Rivet Popper Hypothesis, the popping of a 'key rivet' on the airplane wing represents the loss of a:
- Migratory species
- Redundant species
- Keystone species
- Pioneer species
Explanation: Loss of a keystone species (a key rivet on the wing) poses a much more immediate and severe threat to the ecosystem's structural integrity than losing a redundant species.
The volume of blood pumped by each ventricle during a single contraction is known as:
- Vital capacity
- Cardiac output
- Stroke volume
- Minute volume
Explanation: Stroke volume is the amount of blood ejected from a ventricle with each beat, averaging about 70 ml in a healthy adult.
Which of the following is a common free-living nitrogen fixer in paddy fields?
- Cyanobacteria
- Rhizobium
- Frankia
- Lactobacillus
Explanation: Cyanobacteria (like Nostoc, Anabaena, and Aulosira) serve as an important biofertilizer in paddy fields, fixing atmospheric nitrogen.
The term 'T-DNA' in the context of plant transformation stands for:
- Transfer DNA
- Terminal DNA
- Total DNA
- Template DNA
Explanation: T-DNA is the segment of the Ti-plasmid that is transferred from the Agrobacterium into the host plant's genome.
The system of interconnected protoplasts linked by plasmodesmata throughout the plant is the:
- Apoplast pathway
- Vacuolar pathway
- Transmembrane pathway
- Symplast pathway
Explanation: The symplastic system is the continuous network of living cell cytoplasm that is connected from cell to cell via plasmodesmata.
The 'Antisterility Vitamin' is a common name used for which of the following?
- Vitamin E
- Vitamin B12
- Vitamin C
- Vitamin A
Explanation: Vitamin E is often called the antisterility vitamin because it is necessary for the normal functioning of reproductive organs in many animals.
The mild uterine contractions caused by the fully developed fetus and placenta trigger the release of which maternal hormone?
- Oxytocin
- Prolactin
- Estrogen
- Relaxin
Explanation: This fetal ejection reflex stimulates the maternal pituitary gland to release oxytocin, which in turn causes stronger uterine contractions.
What is the end product of protein digestion that is finally absorbed into the blood?
- Nucleotides
- Fatty acids
- Amino acids
- Glucose
Explanation: Proteins are broken down into peptones, then dipeptides, and finally into individual amino acids by intestinal enzymes.
Which of the following is often called the 'Graveyard of RBCs'?
- Kidney
- Bone marrow
- Liver
- Spleen
Explanation: The spleen filters the blood and removes old or damaged red blood cells from circulation.
Which hormone is responsible for the 'Milk Ejection' reflex during breastfeeding?
- Oxytocin
- Estrogen
- Progesterone
- Prolactin
Explanation: While prolactin stimulates milk production, oxytocin stimulates the contraction of mammary muscles to eject milk.
The epithelial cells of the PCT are rich in which organelle to support active transport?
- Chloroplasts
- Ribosomes
- Mitochondria
- Lysosomes
Explanation: Active reabsorption of glucose and ions requires a large amount of ATP, which is why PCT cells are densely packed with mitochondria.
In amphibians, the structure that represents the ear and receives sound vibrations is the:
- Cochlea
- Pinna
- Tympanum
- Statocyst
Explanation: Amphibians completely lack external ears; instead, a tympanum represents the ear on the surface of their skin.
Consider the following statements about Chrysophytes:
1. They include diatoms and golden algae.
2. They are found only in marine environments.
Which of the above is/are correct?
- 2 only
- 1 only
- Both 1 and 2
- Neither 1 nor 2
Explanation: Chrysophytes are found in both freshwater and marine environments. They are mostly photosynthetic.
The breakdown of complex organic matter by decomposers is:
- Fragmentation
- Humification
- Mineralisation
- Decomposition
Explanation: Decomposition is the process by which decomposers break down complex organic matter into inorganic substances like carbon dioxide, water and nutrients.
The most significant evidence for the 'common ancestry' of all living organisms is the similarity in:
- Body size
- Bone density
- Genetic code
- Habitat choice
Explanation: The fact that almost all organisms use the same DNA/RNA-based genetic code is powerful evidence that all life shares a single origin.
Due to progressive energy loss, the amount of energy reaching the top carnivore is:
- The highest
- Intermediate amount
- Variable amount
- The lowest
Explanation: Since 90% of energy is lost as heat at each trophic transfer, the top carnivore receives the lowest total energy.
In a healthy individual, the normal physiological concentration of blood glucose is roughly:
- 2.0 - 3.0 mM
- 4.2 - 6.1 mM
- 6.5 - 8.0 mM
- 10.0 - 12.0 mM
Explanation: According to NCERT data, the blood concentration of glucose in a normal healthy individual lies in the range of 4.2 to 6.1 mmol/L.
The 'Basal' type of placentation is characteristic of which of the following families?
- Brassicaceae
- Solanaceae
- Fabaceae
- Asteraceae
Explanation: In basal placentation (Sunflower, Marigold), the placenta is at the base of the ovary and a single ovule is attached to it.
In the 'Silk Cotton' tree, the leaf is a classic example of which type?
- Pinnately compound
- Simple leaf
- Palmately compound
- Whorled leaf
Explanation: In palmately compound leaves, the leaflets are attached at a common point, i.e., at the tip of the petiole.
The continuous network of cell walls and intercellular spaces in plants constitutes the:
- Apoplast pathway
- Symplast pathway
- Transmembrane pathway
- Tonoplast pathway
Explanation: The apoplast is the system of adjacent cell walls that is continuous throughout the plant, except at the Casparian strips of the endodermis.
A continuous degradation of a climax community back to a simpler state is termed:
- Retrogressive succession
- Primary succession
- Allogenic succession
- Deflected succession
Explanation: Retrogressive succession happens when a mature community is degraded to a less complex state due to severe environmental stress or overgrazing.
In the Arcata marsh project, the conventional first stage of water treatment strictly involves:
- Bacterial decomposition
- Sedimentation and filtering
- Algal nutrient absorption
- Heavy metal extraction
Explanation: The primary treatment is conventional, involving physical sedimentation, filtering, and chlorine treatment before the water enters the biological marshes.
Consider the following statements regarding Human Leukocyte Antigen (HLA) system polymorphism:
1. The Class III region of the HLA complex encodes several complement components, including C2 and C4, and these proteins participate in the adaptive immune response by facilitating B-cell maturation.
2. The HLA-DR, HLA-DQ, and HLA-DP genes constitute the Class II region, which primarily functions in the presentation of exogenous antigens to CD4+ T-helper cells.
3. The high degree of polymorphism in the HLA complex is primarily concentrated in the peptide-binding groove, which facilitates the recognition of a diverse array of pathogen-derived peptides.
How many of the statements given above are correct?
- Only one
- Only two
- All three
- None
Explanation: Statement 2 is correct. Statement 3 is correct. Statement 1 is incorrect.
Statement 1 is incorrect because while the Class III region encodes complement components like C2 and C4, these proteins are primarily involved in the innate immune response and inflammation rather than B-cell maturation. Statement 2 is correct as HLA-DR, HLA-DQ, and HLA-DP are indeed Class II molecules responsible for presenting exogenous antigens to CD4+ T-helper cells. Statement 3 is correct because the extreme polymorphism of the HLA complex is localized to the peptide-binding groove, which is an evolutionary adaptation that allows the immune system to recognize and respond to a vast, diverse array of pathogen-derived peptides.
Which disorder is characterized by 'fibrosis' or the proliferation of fibrous tissues in the lungs?
- Emphysema
- Bronchitis
- Silicosis
- Asthma
Explanation: Occupational exposure to silica or asbestos dust causes chronic inflammation leading to fibrosis, which seriously damages lung tissue.
A major environmental problem associated with modern sanitary landfills is the:
- Lack of space
- Excessive heat generation
- Rapid organic decomposition
- Immediate land collapse
Explanation: The amount of garbage generated is so high that landfills are rapidly filling up, leading to a severe lack of space.
Biodiversity hotspots are specifically characterized by high endemism and:
- Accelerated habitat loss
- Extreme cold climate
- Zero human population
- Low species richness
Explanation: Hotspots are regions with exceptional concentrations of endemic species that are experiencing exceptional loss of habitat.
What is the primary role of the 'Lacrimal Glands'?
- Storing pigments
- Producing oil
- Filtering light
- Producing tears
Explanation: Lacrimal glands secrete tears that lubricate the eye and contain lysozyme to kill bacteria.
The 'Aqueous Humor' is continuously produced by which part of the eye?
- Retinal layer
- Lacrimal gland
- Ciliary processes
- Corneal endo
Explanation: The ciliary processes in the ciliary body secrete aqueous humor into the posterior chamber, which then flows to the anterior chamber.
Which fungal class includes the highly prized edible delicacies known as Morels and Truffles?
- Basidiomycetes
- Phycomycetes
- Deuteromycetes
- Ascomycetes
Explanation: Morels and truffles are members of Ascomycetes and are considered world-class edible delicacies.
The 'QRS Complex' in a standard ECG signifies which physiological event?
- Ventricular contraction
- Ventricular relaxation
- Atrial relaxation
- Atrial contraction
Explanation: The QRS complex represents ventricular depolarization, which is immediately followed by the contraction of the ventricles.
Which of the following best characterizes early pioneer species?
- High growth rate
- Low dispersal ability
- Long lifespan
- Large seeds
Explanation: Pioneer species are typically r-selected, characterized by high growth rates, wide dispersal, and the ability to tolerate harsh conditions.
Which element was the last to be added to the list of essential plant mineral nutrients?
- Chlorine
- Molybdenum
- Nickel
- Boron
Explanation: Nickel is the 17th essential element, recognized for its role in the enzyme urease, which breaks down urea in plant tissues.
Acetobacter aceti is a bacterium primarily utilized for the production of:
- Citric acid
- Acetic acid
- Butyric acid
- Lactic acid
Explanation: Acetobacter aceti is an aerobic bacterium that converts ethanol into acetic acid (vinegar).
Which photoreceptor cells are more sensitive to light, allowing us to see in dim conditions?
- Cones
- Rods
- Amacrine cells
- Bipolar cells
Explanation: Rods contain the pigment rhodopsin and are highly sensitive to low light levels, though they do not perceive color.
The 'Pellicle' is to a Euglenoid as the ________ is to a human neuron.
- Plasma membrane
- Synaptic vesicle
- Nucleus
- Myelin sheath
Explanation: This is a structural analogy question. Both provide the outer boundary/limitation for the respective biological units.
Which specific type of ultraviolet radiation is responsible for snow blindness?
- UV-B radiation
- Visible light
- UV-C radiation
- UV-A radiation
Explanation: High doses of UV-B cause inflammation of the cornea, known as snow blindness.
An age pyramid that is narrow at the base and broader in the middle is:
- Urn shaped
- Triangular shaped
- Inverted shaped
- Bell shaped
Explanation: An urn-shaped pyramid indicates a declining population where the number of pre-reproductive individuals is lower than reproductive ones.
Ciliary movement is primarily used in the human body for which of the following?
- Pumping blood
- Digesting food
- Removing dust
- Moving limbs
Explanation: Ciliated epithelium in the trachea helps in removing dust particles and microbes inhaled along with atmospheric air.
The IUCN Red List (2004) documents the extinction of how many species in the last 500 years?
- 350 species
- 784 species
- 500 species
- 1000 species
Explanation: According to the IUCN Red List (2004), 784 species (including 338 vertebrates, 359 invertebrates, and 87 plants) have gone extinct in the last 500 years.