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The correct answer is Rennin.

Key Points

• Enzymes are substances (proteins) that act as a catalyst to speed up the metabolism or chemical reactions that occur in our body.
• This results into break down of complex molecules into simpler ones.
• Enzymes help to digest your food.
• This allows the nutrients in food to be easily absorbed into the bloodstream and carried throughout the body.
• They are secreted by salivary glands, pancreas, cells lining the stomach, and small intestine.

Explanation:

Rennin

• Renin is also known as Chymosin.
• It is a type of digestive enzyme secreted by the chief cells in the stomach to digest milk protein.
• Rennin is present in infants as their major diet contains a large amount of milk
• However, adults do not consume a huge amount of milk and hence they lack Rennin enzyme.

Additional Information

The correct answer is Uredospore.

Concept:

• Puccinia graminis is a fungi which uses wheat plants as primary host.
• The dikaryotic phase is completed in the wheat plant.
• The dikaryotic mycelium is well-developed, branched and has two main spore stages - Uredinal and telial.
• The uredinal stage is when the uredospores are formed.
• The Uredospores of Puccinia graminis is formed on wheat.

Explanation:

• Primary infection in wheat begins with the aeciospore germination.
• When the aeciospore reaches the wheat plant, it may attack the leaf, stem, or glumes.
• The dikaryotic mycelium then forms a mass of hyphae below which uredia are formed sub-epidermally.
• The uredia give rise to vertical hyphae in a palisade-like layer.
• The uredia bear uredospores at their swollen tips and form groups called uredosorus.
• Thus, uredospores form in groups known as uredosorus under the epidermis, and appear as reddish-brown pustules.
• The developing uredosori exert pressure on the epidermis such that the pustules rupture.

Important Points

• Uredospores are oval, stalked, unicellular, and binucleate.
• They are thick-walled spores, with 4 round equatorial germ pores.
• The uredospore wall can be differentiated into 3 layers:
• Pellicle - outer layer.
• Exosporium - middle layer.
• Endosporium - inner layer.
• The uredospores can be dispersed by the wind and hence spread rust to other plants.
• In favourable conditions (i.e., during the winter season), the uredospores germinate to infect the wheat plant.
• During a single season, the procedure may be repeated several times.

The correct answer is two.

Hint

Genus (Singular) or Genera (plural) 

• A genus is a taxonomic rank among the eight major taxonomic ranks in biological classification. It is below the family and above the species.

Key Points

• Chordates & their characteristics 
• Presence of Notochord.
• The central nervous system is dorsal, hollow, and single.
• Pharynx perforated by gill slits.
• The heart is central.
• A post-anal part (tail) is present.
• Phylum Chordata is divided into three subphyla- Urochordata, Cephalochordata and Vertebrata.

Explanation:

• Cephalochordata, often referred to as protochordate, is a taxon of marine invertebrate chordates comprising 30 species belonging to two genera -

1. Branchiostoma (earlier known as Amphioxus)
2. Epigonichthys (earlier called Asymmetron).

• Taxonomic Classification:
• Kingdom - Animalia
• Super-phylum - Deuterostomia
• Phylum - Chordata
• Sub-phylum - Cephalochordata
• Class - Leptocardii
• Family - Branchiostomatidae
• Genus - (1) Branchiostoma and (2) Epigonichthys (or Asymmetron)

Additional Information

Characteristics of Amphioxus (also known as Lancelet)

• Cephalochordata is additionally called acrania.
• They belong to any of the two dozen species having a place with the subphylum Cephalochordata of the phylum Chordata.
• Habit: They are exclusively marine, small fish-like animals that rarely exceed 5 cm in length.
• Habitat: Lancelets partly live buried in soft marine sediments.
• Notochord: It extends throughout the length of the body and is present throughout life.
• Tail: Post-anal tail is present.
• Circulatory system: Closed circulatory system is present.
• Body fluid: Blood is without pigment.

The correct answer is heredity.

Hint

Heredity:

• It is the transmission of genetic characteristics (traits) from parents to offspring.
• As a result, the offspring look similar in some aspects to parents.
• Heredity takes place through reproduction.
• Traits may be - color, height, skin complexion, etc.

Reproduction: 

• It is the process by which (parent) organisms give rise to new young ones (offspring).
• Reproduction is either asexual or asexual.
• In asexually reproducing organisms offspring looks identical to parents like plants and bacteria
• However, in sexually reproducing organisms variation (differences in traits) arise in offspring.

Inheritance:

• Process of transfer of genetic traits and their expression from one to another generation.
• Genetic information is stored in the DNA, which can be passed on to the next generation through reproduction..

Explanation

Mistake Points

• Please note that 'heredity' and 'hereditary' are words with different meanings.
• 'Heredity' refers to the process of transfer of characters from one generation to another.
• Whereas, 'hereditary' refers to the character that can be transferred from one generation to another.
• For example, haemophilia is a hereditary disease, meaning it can be transmitted by heredity.

The correct answer is 33.

Key Points

• Hirudinaria granulosa is a scientific name of Common Indian Cattle leech.
• It is a blood-sucking (sanguivorous) ectoparasite on cattle and humans.
• It is found in freshwater tanks, ponds, lakes, swamps, and slow streams.
• It takes food by sucking the blood of fishes and frogs, and also of cattle or human beings when they enter the pond.
• Taxonomic classification of H. granulosa 
• Kingdom - Animalia
• Phylum - Annelida
• Class - Clitellata
• Sub-class - Hirudinea
• Order - Gnathobdellida
• Family - Hirudinidae
• Genus - Hirudinaria
• Species - H. granulosa

Explanation

• The body of Hirudinaria is soft, vermiform, elongated, bilaterally symmetrical, and metamerically segmented.
• There are 33 body segments, each having five superficially marked annuli except the few anterior and posterior ones.
• The segments can be divided into 6 regions:​​

Additional InformationGeneral characteristics of Hirudinaria :

• The body is elongated with the convex dorsal surface and flat ventral surface.
• The dorsal surface is dark green, and the ventral surface is yellowish-brown.
• Size varies from 6 to 10 cm in length.
• However, leeches may contract or elongate their body much beyond the limits mentioned.
• The body surface always remains moist due to the secretion of mucus from the body wall.
• At the anterior end on the ventral surface, a cup-shaped anterior sucker is present.
• The mouth is present in the center of the anterior sucker.
• A ventral sucker is also present at the posterior end of the body.
• Anus is present on the dorsal side at the junction of the last metamere and the posterior sucker.
• Hundred or more very closely arranged grooves or annuli are present on the body surface.
• Each of the five anterior metameres bears a pair of eyes on the dorsal margin, each looking like a dark spot.
• There are 17 pairs of ventro-laterally arranged nephridiopores in the metameres starting from 6^th to 22^nd metameres.
• The male and female genital apertures are present on the ventral side in the middle of the 10^th and 11^th metameres.

Mistake Points

• Please note that the official answer key shows option 1 as the correct answer but we have marked option 4.
• Also note that the options given for this question are a little ambiguous and so, we are choosing the best possible answer.
• Option 1 is a characteristic feature of Amphioxus and hence, it cannot be "not true".

Key Points

• Notochord persists throughout life: TRUE
• Amphioxus belongs to the sub-phylum Cephalochordata of Chordata phylum.
• ​The notochord in Amphioxus extends the whole length of the body.
• It is persistent throughout its life, which is a distinctive feature of Cephalochordata.
• ​Nerve cord dorsal to notochord: TRUE
• The central nervous system of an adult Amphioxus consists of a tubular nerve cord.
• The nerve cord lies dorsally to the notochord.
• Brain absent; very little cephalization: TRUE
• Cephalization is the process in which the nervous and sensory tissues become organized in the head region that marks the anterior end of the animal.
• Amphioxus does not have enough cephalization to form a head or brain.
• It has a swelling of the nerve cord at the anterior end that forms a brain vesicle.
• The very little cephalization involves the feeding structures being organized towards the anterior end along with a pigment spot.
• Free swimming organism: NOT TRUE
• Amphioxus larvae are free-swimming but adults usually do not swim.
• Adults are burrowing animals that live in shallow waters and remain buried in the sand for most part.

Key Points

• Scoliodon or dogfish is a cartilaginous fish belonging to the class Chondrichthyes.
• There are 10 pairs of cranial nerves arising from different parts of the brain and are distributed in the anterior region of the body.

Concept:

• Phyllotaxy is the pattern of arrangement of leaves on the stem or the branch of a plant.
• There are 3 main types of phyllotaxy:
• Alternate - A single leaf arises from each node. E.g. - China rose, Mustard.
• Opposite - A pair of leaves arise at each node and lie opposite each other. E.g. - Guava, Calotropis.
• Whorled - More than 2 leaves arise at each node and form a whorl. E.g. - Alstonia, Nerium.

Additional Information

• There are some other spiral forms of phyllotaxy in which leaves are arranged in vertical rows called orthostichies.
• These are of the following types:
• Distichous - There are 2 orthostichies so that every 3^rd leaf base is vertically above the 1^st leaf base. E.g. - Graminae.
• Tristichous - There are 3 orthostichies such that every 4^th leaf base is vertically above the 1^st leaf base. E.g. Cyperaceae.
• Pentastichous - There are 5 orthostichies so that every 6^th leaf base is vertically above the 1^st leaf base. E.g. - Ficus benghalensis.
• Octastichous - There are 8 orthostichies so that every 9^th leaf base is vertically above the 1^st leaf base. E.g. - Carica papaya.

Concept-

• Essential fatty acids are those fatty acids which we get from the food supplement and that the body cannot produce.
• It is used to fulfill the requirement of fatty acids for biological processes.

Key Points

• Linoleic acid (LA) is an omega-6 fatty acid which is considered an essential fatty acid because it cannot be synthesized by humans.
• In all omega-6 (ω6 or n-6) fatty acids, the first double bond is located between the sixth and seventh carbon atom from the methyl end of the fatty acid.
• Linoleic acid is a colorless to straw colored liquid.
• It is a polyunsaturated fatty acid essential to human diet.
• After consumption and absorption by enterocytes lining the small intestines, linoleic acid is packaged into chylomicrons as phospholipids, triacylglycerols, or cholesterol esters and enters the general circulation (subclavian vein) via the thoracic duct.
• Linoleic acid is delivered to hepatic and extrahepatic tissues as chylomicrons are delipidated en route to and cleared by the liver during its transition to much smaller remnant particles.
• After cellular uptake, the fate of linoleic acid is determined by the needs of the tissue, i.e., incorporation into membrane phospholipids, desaturation and elongation, etc.
• The major dietary sources of linoleic acid are vegetable oils, nuts, seeds, meats, and eggs.

Additional Information Acetic acid-

• Acetic acid is an aliphatic organic acid.
• It is a hygroscopic, corrosive liquid with a vinegar-like odor.
• It can be synthesized by oxidizing acetaldehyde in the presence of manganese or cobalt salts.
• It is utilized for synthesizing acetic anhydride, cellulose acetate and acetic esters.

Propionic acid-

• Propionic acid is a short-chain saturated fatty acid comprising ethane attached to the carbon of a carboxy group.
• It has a role as an antifungal drug. It is a short-chain fatty acid and a saturated fatty acid. It is a conjugate acid of a propionate.
• Propionic acid (PA) is used as a preservative in foods such as cheeses, baked goods, or additive for artificial fruit flavors.

Palmitic acid-

• Palmitic Acid is a saturated long-chain fatty acid with a 16-carbon backbone.
• Palmitic acid is found naturally in palm oil and palm kernel oil, as well as in butter, cheese, milk and meat.
• It is a long-chain fatty acid and a straight-chain saturated fatty acid. It is a conjugate acid of a hexadecanoate.

The correct answer is Plasmin.

Concept:

• Fibrinolysis is the process by which blood clots are prevented from growing and becoming problematic.
• Primary fibrinolysis is a body process, whereas secondary fibrinolysis is the breakdown of clots caused by a medication, a medical issue, or another factor.
• Fibrinolysis is the breakdown of a fibrin clot, which is the result of coagulation.

​Explanation:

• In the liver, plasminogen, an inactive form of plasmin, is produced.
• Despite the fact that plasminogen cannot cleave fibrin, it has an affinity for it and is incorporated into the clot when it forms.
• Plasmin degrades fibrin into soluble components known as fibrin degradation products (FDPs).
• FDPs compete with thrombin, which is the enzyme to convert fibrinogen to fibrin.
• Hence they slow down the formation of blood clots by blocking fibrinogen conversion to fibrin.
• These fibrin monomers otherwise polymerize to form long, sticky fibres.
• The fibrin threads form a fine network of threads, in which dead and damaged formed elements of blood are trapped.
• Plasmin is the proteolytic enzyme that inactivates the coagulation factors by cleavage.
• Thus, plasmin is fibrinolytic as well as anticoagulant in function.
• It plays a crucial role in removing unnecessary clots in blood vessels and restoring normal blood flow.

 Additional Information

• Hemin-
• ​It is made from red blood cells extracted from human blood.
• Hemin acts by lowering the production of a specific enzyme in the body.
• Thrombin-
• ​It acts as a proteolytic enzyme to convert fibrinogen molecule to insoluble fibrin monomer.
• It is obtained by the activation of prothrombin.
• Prothrombin-
• ​It is called Factor II and is the inactivated form of thrombin.
• It is synthesized in the liver in the presence of vitamin K.