SRMJEEE Biology Mock Test - 5 - JEE MCQ

Muscles are a specialized tissue that contributes about 40-50% of the body weight in a human adult. This high percentage is due to the extensive network of muscles required for various movements and locomotion, highlighting the importance of muscular system in our daily activities.

Line in NCERT: "About 40-50 per cent of the body weight of a human adult is contributed by muscles."

Leukocytes are primarily categorized into two main types: granulocytes and agranulocytes. This classification is based on the presence or absence of granules in their cytoplasm. Granulocytes include neutrophils, eosinophils, and basophils, which are involved in inflammatory and allergic reactions. Agranulocytes, which include lymphocytes and monocytes, play roles in adaptive immunity and phagocytosis.

Line in NCERT: "Leucocytes are generally short lived. We have two main categories of WBCs - granulocytes and agranulocytes."

When the external intercostal muscles and diaphragm relax, the ribs move downward and inward and diaphragm becomes convex (dome shaped), thus decreasing the volume of thoracic cavity and increasing the pressure inside as compared to the atmospheric pressure outside. This will cause the air to move out (expiration).

9 + 2 arrangement of the axonemal microtubules of cilia/flagella 

The anther is the part of the stamen (male reproductive organ of a flower) responsible for producing pollen grains. Pollen grains contain the male gametes necessary for the fertilization of the ovules.

Line in NCERT: "Each anther is usually bilobed and each lobe has two chambers, the pollen-sacs. The pollen grains are produced in pollen-sacs."

The structure for hemoglobin is very similar to myoglobin except that it has a quaternary structure due to the presence of four protein chain subunits.Each protein chain subunit contains a heme group with the iron attached. Each hemoglobin molecule can bind to a total of four oxygen molecules.

Topic in NCERT: quaternary structure of proteins
Line in NCERT: "Some proteins are an assembly of more than one polypeptide or subunits. The manner in which these individual folded polypeptides or subunits are arranged with respect to each other ... is the architecture of a protein otherwise called the quaternary structure of a protein.Adult human haemoglobin consists of 4 subunits. Two of these are identical to each other. Hence, two subunits of α type and two subunits of β type together constitute the human haemoglobin (Hb).

The pineal gland secretes melatonin, a hormone that regulates sleep-wake cycles and circadian rhythms. Melatonin levels typically rise in the evening to promote sleep and decrease in the morning to help wake up.

Line in NCERT: "The pineal gland secretes a hormone called melatonin."

Pleuro Pneumonia Like Organisms (PPLOs) also called mycoplasma are considered as smallest free living organism. It do not contain cell membrane or cell wall and present as fluid. It causes disease in plants.
Topic in NCERT: CELL: THE UNIT OF LIFE
Line in NCERT: "The smallest cells, mycoplasmas, are only 0.3 µm in length while bacteria could be 3 to 5 µm.

The myelin sheath is a fatty layer that surrounds the axon of some nerve cells, forming an electrically insulating layer. It is essential for the proper functioning of the nervous system. The myelin sheath speeds up the transmission of nerve impulses along the axon by insulating the nerve fiber and allowing electrical impulses to jump from one node of Ranvier to the next, in a process known as saltatory conduction. This significantly increases the speed of nerve signal transmission.

The Proximal Convoluted Tubule (PCT) is responsible for the reabsorption of water and solutes from the filtrate. It plays a key role in recovering essential nutrients and water from the urine back into the bloodstream, thereby conserving valuable resources for the body.

Line in NCERT: "Nearly all of the essential nutrients, and 70-80 per cent of electrolytes and water are reabsorbed by this segment."

Telophase I, is followed by an interphase, called interkinesis, similar to the mitoticinter phase. During interkinesis the chromatin is partially uncoiled; however, there is no replication of the genetic material, because each chromosome already consists of two chromatids.

Line in NCERT: "The stage between the two meiotic divisions is called interkinesis and is generally short lived."

Parietal:

• This type of placentation is found in the unilocular syncarpous ovary. In it, the ovule develops on the inner wall of the ovary or on the peripheral part.
• Ovary becomes bi or multilocular due to the formation a false septum.
• For example, Cucurbita, Argemone and Cruciferae family (Mustard). 

Axile:

• It is found in multicarpellary syncarpous gynoecium. The fusion margin of carpels grows inward and meets in the centre of the ovary.
• Thus, an axis forms in the centre of the ovary and the ovary becomes multi-chambered. The ovules are borne at the central axis.
• A number of these chambers are equal to the number of the carpel.
• For example,  Potato, China rose, Onion, Lemon, Orange, Tomato.

Adrenal cortex secretes mineralocorticoids like aldosterone which increase the reabsorption of Na⁺ and water from renal tubule that prevent diuresis. Diuresis is a condition in which the kidneys filter too much bodily fluid. 

In the floral formula, "G(2)" represents a bicarpellary, syncarpous gynoecium, indicating that the flower has two carpels that are fused together. This part of the formula provides information about the structure and organization of the female reproductive part of the flower.

Topic in NCERT: Gynoecium
Line in NCERT: The floral formula is represented by some symbols. In the floral formula, Br stands for bracteate K stands for calyx , C for corolla, P for perianth, A for androecium and G for Gynoecium, G for superior ovary and G for inferior ovary, for male, for female, for bisexual plants, ⊕ for actinomorphic and for zygomorphic nature of flower. Fusion is indicated by enclosing the figure within bracket and adhesion by a line drawn above the symbols of the floral parts. A floral diagram provides information about the number of parts of a flower, their arrangement and the relation they have with one another . The position of the mother axis with respect to the flower is represented by a dot on the top of the floral diagram

Prokaryotic cells, such as bacteria, do not have a well-defined nucleus. Instead, their genetic material is located in a nucleoid region where DNA is not enclosed by a membrane. This is a key difference between prokaryotic and eukaryotic cells, the latter having a well-defined, membrane-bound nucleus.

Condensation initiates in prophase.

The average weight of an adult human kidney is between 120 to 170 grams. This is an important fact because the kidneys play a crucial role in filtering waste from the blood and maintaining the body's fluid balance. Their size and weight reflect their significant workload and functional capacity in the body.

Line in NCERT: "Each kidney of an adult human measures 10-12 cm in length, 5-7 cm in width, 2-3 cm in thickness with an average weight of 120-170 g."

The correct matching of respiratory capacities with their respiratory volumes are:

Size and shape of the cells vary with the functions they perform. In unicellular organism a single cell constitutes the entire organism. The components in all eukaryotic cells are more/less the same. Centrioles are present in animal cells but absent in plant cells.

The protienous part of an enzyme is known as apoenzyme.

Line in NCERT: "Enzymes are composed of one or several polypeptide chains. However, there are a number of cases in which non-protein constituents called co-factors are bound to the enzyme to make the enzyme catalytically active. In these instances, the protein portion of the enzymes is called the apoenzyme."

Calcium ions play a crucial role in muscle contraction by binding to troponin. This action removes the inhibition that prevents actin and myosin from interacting, thereby facilitating the formation of cross-bridges between these filaments, which is essential for muscle contraction.

Line in NCERT: "Increase in Ca** level leads to the binding of calcium with a subunit of troponin on actin filaments and thereby remove the masking of active sites for myosin."

Hypersecretion of growth hormone in adults leads to acromegaly, characterized by abnormal growth of the hands, feet, and face, due to the enlargement of bones and tissues.

Line in NCERT: "Excess secretion of growth hormone in adults especially in middle age can result in severe disfigurement (especially of the face) called Acromegaly, which may lead to serious complications,"

The striated appearance of skeletal muscles is due to the arrangement of actin and myosin filaments. The alternating dark (A bands) and light (I bands) stripes are caused by the distribution pattern of these two important proteins, with actin forming the thin filaments and myosin forming the thick filaments.

Line in NCERT: "The detailed study of the myofibril has established that the striated appearance is due to the distribution pattern of two important proteins – Actin and Myosin."

A represents polypeptide chain C which is removed prior to insulin formation

Topic in NCERT: Genetically engineered insulin

Line in NCERT: "insulin consists of two short polypeptide chains: chain a and chain b, that are linked together by disulphide bridges."

Trichoderma polysporum is a fungal species that is known to make cyclosporine A compound. This compound exhibits antifungal and anti-inhibitory properties. The key property of this compound is that it is able to inhibit the activation of T-cells. These cells are involved in recognizing foreign and self elements. During the time of grafting usually, our body rejects the graft as T-cells recognize it as foreign. But using cyclosporine A we can inhibit this rejection by T-cells. So, the medical application of Cyclosporin A is an immunosuppressive agent.
Monascus purpureus is a yeast strain belonging to the fungus that is known to make statin. Statin is a competitive inhibitor of cholesterol synthesis. This means that it negatively affects the cholesterol synthesis process. So, its medical application is that it is used to lower blood cholesterol levels.
Thus, from the above discussion, we can conclude that option A is the correct answer.

'A' is vena cava that carries deoxygenated blood
'B' is aorta that carries oxygenated blood
'C' is pulmonary artery that carries deoxygenated blood
'D' is pulmonary vein that carries oxygenated blood.

• A: Light band present on the myofibril is called I-band or isotropic band. It consists of only actin filaments.
• B: Sarcoplasm is enclosed by sarcolemma which contains many nuclei.
• C: Myofibril is made up of two types of myofilaments which are thick and thin.
• D: Sarcolemma is the plasma membrane of muscle fibre.
• E: Nucleus
• F: Dark band present on the myofibril is called A-band or anisotropic band.

So, the correct answer is 'A- light band, B- sarcoplasm, C- myofibril, D- sarcolemma, E- nucleus, F- dark band'.

Topic in NCERT: Myofibrils

Line in NCERT: "each myofibril has alternate dark and light bands on it."

In the given figure depicting the respiratory passage in man, the unidentified parts are as follows: (A) Alveolar sac, (B) Secondary bronchus, (C) Alveoli, (D) Bronchioles, and (E) Trachea.

'A'-lymph nodes, 'B'-Thymus, 'C'-spleen, 'D'-Bone marrow. Thymus and bone marrow are the primary lymphoid organs where maturation of T-cells and B-cells take place respectively. Lymph nodes and spleen are the secondary lymphoid organs where T-cells and B-cells undergo proliferation and differentiation.