Sample AFMC Biology Mock Test

Pepsin, rennin, and trypsin are digestive enzymes. 

Pepsin and renin are enzymes secreted by the gastric pits in the stomach. They are the active forms of pepsinogen and prorenin respectively, which activate when they come into contact with the hydrochloric acid in the stomach. 

Glycogen is mainly stored in the liver and the muscles and provides the body with a readily available source of energy if blood glucose levels decrease.

The cystic duct connects the top of the gallbladder’s neck to the common hepatic duct.
It then joins the common bile duct, which meets the pancreatic duct before it empties into the duodenum.

Illustration of Gallbladder Network:

The chief cells in the stomach secrete pepsinogen which activates to form pepsin. Pepsinogen is converted to pepsin under the effect of gastric juices and hydrochloric acid.

Pepsin is secreted by the Zymogen cells of the stomach.

• People with type A blood have antigen A on the surface of their RBCs, while people with type B blood have the B antigen. Individuals with type AB blood have both A and B antigens, whereas people with type O blood have no antigens present (there is no antigen O).
• The antibody that reacts against antigen A is called anti-A and is found in the plasma of people who do not possess antigen A on their own RBCs – that is, people with type O or type B blood.
• The antibody that reacts against antigen B is called anti-B and is present in those who do not possess antigen B in their RBCs – people with type O or type A blood.

The appearance of new characters or traits in the progeny, compared with parents are called Variations.
These are due to the Independent assortment and Crossing over.

Independent assortment: When a cross is made between two individuals different from each other in two or more characters, then the inheritance of one character is independent of the inheritance of another character. It is called Law of independent assortment.

Crossing over: Exchange of chromatid segments between the non-sister chromatids of a bivalent is called crossing over.

Beriberi is caused by the deficiency of vitamin- B1 (thiamine).

Vitamin K is essential for blood clotting and deficiency of it causes hemorrhage.

Riboflavin (Vitamin B₂) is the precursor of two coenzymes known as flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD).
Both are essential for tissue respiration and the generation of energy from the metabolism of carbohydrates, amino acids, and fats.

Basophils are circulating granulocytes that respond to allergic stimuli by migrating and accumulating at sites of allergic inflammation.

They contain cytoplasmic granules with similar histamine levels per cell as mast cells.

Among the White blood cells (WBCs) four cells have the phagocytic ability: Neutrophils, Monocytes, Eosinophils, and Basophils.

• When monocytes leave the blood and enter tissue spaces they grow and modify to form macrophages that still have the phagocytic ability.
• The basophils and the eosinophils have very little phagocytic ability when compared to the phagocytic ability of neutrophils and monocytes.

Letter S in structural unit of ribosome refers to Svedberg unit which is a non-metric unit for sedimentation rate.
The sedimentation rate for a particle depends on its density, shape, and mass which collectively decides how fast the particle 'settles'.
The higher value of S means molecules will settle faster than lower S value molecules. 

Testosterone is responsible for the development of secondary sex characteristics, features that stimulate male development (including characteristics that are not part of the reproductive system, such as facial hair growth and voice change).

The heartbeat originates from the sino-atrial node found in the upper part of the right auricle. It is a specialized type of cell, which generates the impulses required to start the first heartbeat.

Hence, it is known as the natural pacemaker of the heart

Thyroxine is the main hormone secreted into the bloodstream by the thyroid gland.

Thyroid hormones play vital roles in regulating the body’s metabolic rate, heart, and digestive functions, muscle control, brain development, and maintenance of bones.

Prothrombin is a protein made by the liver. Prothrombin helps blood to make normal clots.

The "prothrombin time" is one way of measuring how long it takes blood to form a clot, and it is measured in seconds (such as 13.2 seconds)

Kala-azar is caused by bites from female phlebotomine sandflies – the vector (or transmitter) of the leishmania parasite.

The sand flies feed on animals and humans for blood, which they need for developing their eggs.
If blood containing leishmania parasites is drawn from an animal or human, the next person to receive a bite will then become infected and develop leishmaniasis.

Cryopreservation: Cryopreservation [preservation in the frozen state (cryo means extreme cold, derived from Latin word kruos = ‘frost’)] is based on the reduction and subsequent arrest of metabolic functions of biological material by the imposition of ultra-low temperature.

Cholera is caused by bacteria called Vibrio cholera. The disease deadly effects are the result of a strong toxin known as CTX that is produced by these bacteria in your small intestine

The two genes that produce red and green light-sensitive proteins are located on the X chromosome. Mutations in these genes can cause color blindness.
Color blindness is a common inherited sex-linked disorder that affects a person's ability to see or recognize certain colors. It affects males much more often than females.

• Heroin is a semisynthetic opiate. Opiates are derived from opium which is dried latex of unripe capsular fruits of the poppy plant (Papaver somniferum belonging to family Papaveraceae).
• Opiates have analgesic, narcotic and sedative effects. Heroin is formed from the acetylation of morphine (a natural opiate). It is also known as H-smack or Brown sugar.
• It is a white and odorless crystalline compound having a bitter taste. It is three times more potent than morphine.

Afforestation is the establishment of a forest or stand of trees (forestation) in an area where there was no previous tree cover.

Many government and non-governmental organizations directly engage in programs of afforestation to create forests, increase carbon capture and carbon sequestration, and help to anthropogenically improve biodiversity. 

By definition, a true coelom is a coelom lined by mesoderm on both sides, because true coelom is produced either by splitting in the mesoderm or by fusion of mesodermally lined pouches.

Brunner's glands (or duodenal glands) are compound tubular submucosal glands found in that portion of the duodenum which is above the hepatopancreatic sphincter (a.k.a. sphincter of Oddi).

• Sea snakes, venomous elapid snakes that inhabit marine environments, are the most abundant and widely dispersed group of poisonous reptiles in the world. 
• Sea snakes are characterized by laterally compressed bodies and vertically flattened tails and nostrils with valve-like flaps, giving them an eel-like appearance.

Ascariasis can be treated by antihelminthic drugs such as Alcopar, Antipar, santonin, chenopodium oil and Tetrachloroethylene etc.

Nekton or necton refers to the aggregate of actively swimming aquatic organisms in a body of water.

The term was proposed by German biologist Ernst Haeckel to differentiate between the active swimmers in a body of water, and the passive organisms that were carried along by the current, the plankton.

•  Krait venom is extremely neurotoxic and induces muscle paralysis, its bite is lethal to man. There are 12 species and 5 sub-species of Krait Snakes, Some of them are the common krait, banded krait, and Indian Krait.
• The Bungarus, commonly referred to as Kraits is the most dangerous venomous snake of India and one of the deadliest snakes in the world. The maximum number of deaths of common krait per bite is 60, It can be seen in the deep jungles of India.

Trochophore larva is a small, translucent, free-swimming larva characteristic of marine annelids and most groups of mollusks. They are spherical or pear-shaped and are girdled by a ring of cilia the prototroch, that enables them to swim.

Hence, option D is correct.

The frog’s skin surface has mucous glands which make it moist and through its moist skin it respires most of the time. So, it possesses mucous glands but not sweat glands and sebaceous glands. They also possess poisonous glands to protect themselves from predators

Nephridia and setae are found in Annelids.

Option A: Sea Urchin is an echinoderm animal.
Option B: Sea Mouse is an Annelida animal.
Option C: Sea Anemone belong to phyla Cnidaria.
Option D: Sea Pen belongs to phyla Cnidaria.

Hence, option B is correct.

Spirogyra species can reproduce both sexually and asexually.

• Asexual, or vegetative, reproduction: occurs by simple fragmentation of the filaments.
• Sexual reproduction: occurs by a process known as conjugation, in which cells of two filaments lying side by side are joined by outgrowths called conjugation tubes.

Arthropods are joint-legged animals.
Some prominent ones include:
Insects, spiders, ants, cockroaches, bees, crabs, shrimps, millipedes, centipedes, etc.

• Gymnosperms, for example. Cycas, Pinus, Cedrus, etc, bear reproductive structures in the form of cones.
• The cones that bear female reproductive structures are called female cones. Each female cone contains spirally arranged megasporophylls, that have ovules directly attached to them,  that is, ovules not enclosed in the ovary or are naked.
• After fertilization, the ovule forms the seed and the ovary forms the fruit. Since in gymnosperms ovary is absent fruits are not formed.

Difference between Angiosperm seeds v/s Gymnosperm seeds:
​

Plants require this mineral (Zn) only in traces and its higher concentrations are highly toxic.

The largest-sized flower in the world is Rafflesia Arnoldii which is found in Indonesia. And it is a parasitic plant that has no roots or leaves. Bcoz of that reason they use their haustoria that use to suck nutrients from the roots of other plants. So they are known as total root parasites.

Image of Rafflesia Arnoldi:

Tyloses are outgrowths on parenchyma cells of xylem vessels of secondary heartwood. When the plant is stressed by drought or infection, tyloses will fall from the sides of the cells and "dam" up the vascular tissue to prevent further damage to the plant.

Martynia is a monotypic genus in the Martyniaceae family consisting of a single species, Martynia annua L., which is commonly known as cat's claw, tiger's claw, or iceplant.

In humans, the membrane that covers the brain (and a majority of the spinal cord) is called the meninges. 

It is a fibrous membrane of tissue composed of three layers:
(i) the dura mater
(ii) arachnoid mater
(iii) pia mater.

• Chrysanthemum is propagated vegetatively either through root suckers or terminal cuttings.
• Suckers arise from the underground stem and these are separated and planted in prepared nursery beds during January for stock plants.

• The bony labyrinth is the cavity of the inner ear. It consists of the central vestibule, the semicircular canals, and the cochlea.
• Inside the bony labyrinth lies a complicated membranous sac called the membranous labyrinth.
• The small space between the wall of the bony labyrinth and the wall of the membranous labyrinth is filled with a fluid called perilymph.
• The space within the membranous labyrinth is filled with endolymph.

A dorsal root ganglion is also known as a posterior root ganglion, is a cluster of neurons (a ganglion) in a dorsal root of a spinal nerve.

The cell bodies of sensory neurons known as first-order neurons are located in the dorsal root ganglia.

Humans have a pair of kidneys that filter our blood & removes the poisonous substance from the blood.
So, in that case, when one kidney is removed from the body, another kidney will work and the person can survive and remain normal.

• Photorespiration imposes costs on plant energy metabolism.
• The oxygenase reaction of RUBISCO does not result in energy or carbon gain for the plant. The ribulose-1,5-bisphosphate molecule for this reaction is therefore “wasted”. 

Reproductive isolation term given by Ernest Mayer. This collection is evolutionary mechenism and depend on behavior and physiological process. They prevent members of different species from producing progany or ensure that any offspring are sterile.

A few animals have evolved to supplement their energy needs by temporarily harboring chloroplasts, having ingested them through grazing on algae.
Autotrophy does not provide enough energy to fuel the activities of animals.

• A clone is a group of the organism produced from a single parent through asexual reproduction or progeny of a single plant obtained by asexual reproduction while in other processes like hybridization, cross-pollination, and self-pollination mixing of two gametes is taking place.
• Micropropagation is the process of the multiplication of somatic cells artificially. During this process, the same type of cells (morphologically and genetically) are formed. such groups of cells are called clones. 

• Anatropous ovules are the most common type of ovules, which occur in more than 80 percent of angiosperm families.
• The body of the ovule is rotated 180° and the micropyle reaches the funiculus.
• In the straight line, Chalaza and micropyle lie, but hilum is the micropyle at 90°.
  Thus, the micropyle is similar to the funiculus.
• There is also a ridge in the ovule, as the body of the ovule is fused with the funiculus. In this case, during development, the ovules become completely inverted so that the micropyle lies close to the hilum.
• The hilum is a scar that marks the point where the funicle connects the seed to the fruit wall.

Hence,option A is correct.

Atropine is a non-selective muscarinic antagonist that is mainly used as an adjunct for anesthesia.

Belladonna is a poisonous plant and belladonna intoxication from accidental ingestion may result in a severe anticholinergic syndrome, which is associated with both central and peripheral manifestation.

Adam's Apple represents thyroid cartilage of larynx which helps to protect the frontal part of the larynx.

The Greek philosopher Aristotle (384–322 BC) was one of the earliest recorded scholars to articulate the theory of spontaneous generation, the notion that life can arise from nonliving matter.