VITEEE Biology Test - 10 - JEE MCQ

The correct answer is Option B: Coordinating electrical activity in the atria with electrical activity in the ventricles by connecting them via the bundle of His. The atrioventricular node (AV node) and the bundle of His play critical roles in ensuring proper cardiac function by allowing the transmission of electrical signals from the atria to the ventricles. This connection overcomes the insulating barrier of connective tissue between the atria and ventricles, ensuring that the ventricles contract in a coordinated manner after the atria, optimizing the heart's ability to pump blood efficiently.

Cellular barrier involves cells like neutrophils that act to fight infections.
Cytokine barrier includes proteins like interferons that mediate immune responses.
Physical barrier refers to substances like mucus that trap pathogens.
Physiological barrier involves physiological factors like HCl in gastric juice, which kills microorganisms.

Hence, the correct match is:
(a) – (iii) Neutrophils
(b) – (i) Interferons
(c) – (ii) Mucus
(d) – (iv) HCl in gastric juice

During ventricular systole, the contraction of ventricular muscles causes the closure of bicuspid and tricuspid valves (AV valves), producing a low pitched 'lubb' sound. At the end of ventricular systole, semilunar valves close, producing the second heart sound, the 'dup'. Pulsation of the radial artery is due to rhythmic contraction and relaxation in the aorta. Initiation of the heart beat occurs in the SA node.

The pituitary gland is a tiny organ, the size of a pea, found at the base of the brain. As the “master gland” of the body, it produces many hormones that travel throughout the body, directing certain processes or stimulating other glands to produce other hormones.

Inspiratory reserve volume (IRV) + tidal volume (TV) + expiratory reserve volume (ERV) represents vital capacity (VC). Now, inspiratory capacity is the total volume of ai that can be inhaled after a normal expiration. It includes tidal volume and inspiratory reserve volume i.e., IC = TV + IRV. Thus, option (a) is correct which says that vital capacity i.e., IRV + TV + ERV = IC + ERV.

• The pleural membranes are two layers of the serous membrane which enclose and protect the lung.
• The superficial layer is called the parietal pleura and lines the wall of the thoracic cavity.
• The deep layer is called the visceral pleura and covers the lungs themselves.

Hence, the correct option is B.

NCERT Reference: Topic- Human Respiratory System of "Breathing and Exchange of Gases" of NCERT 

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

Grass is the correct option because veins on the lamina run parallel to one another is called parallel venation. It is characteristically found in monocot plants and grass is a characteristic of monocot plant.

Hence, the correct option is B.
NCERT Reference:  Topic “Venation” of chapter Morphology of Flowering Plants. 

Over-exploitation: The Passenger pigeon (ii) was over-exploited to extinction.
Ex-situ conservation: Botanical gardens (iii) are used for ex-situ conservation, preserving species outside their natural habitats.
Alien species invasions: Nile perch (iv) is an example of an alien species that invaded Lake Victoria, affecting local biodiversity.
In-situ conservation: Sacred groves (i) represent in-situ conservation, where areas are preserved within their natural habitats, often due to cultural reasons.

• In hypogynous flower, gynoecium occupies the highest position.
• Superior ovary is present in hypogynous flower.
• In epigynous flower, gynoecium is the bottom most whorl. China rose is an example of hypogynous flower.

Halophile - Bacteria residing in salty areas
Thermoacidophiles - Bacteria residing in hot springs
Methanogens - Bacteria which survives in marshy area
Basophiles - Bacteria which survives in alkaline medium.

Option (c) is the correct answer as pneumotaxic centre is present in the pons region of the brain, that can moderate the functions of the respiratory rhythm centre.

Option (b) is incorrect as medulla oblongata possesses respiratory rhythm centre and a chemosensitive area.

Option (a) and (d) are incorrect as cerebrum and thalamus does not possess any specialised centre to moderate the respiratory rhythm to suit the demands of the body tissues.

In the given figure the exchange of respiratory gases occurs in alveolar cavity.
The thickness of the alveolar-capillary barrier varies from 0.2 to 2.5 pm. The wall of the capillary endothelial cell is fused to that of the alveolar cell with only a very thin basement membrane between these two cells. This produces a very narrow gap across which oxygen and carbon dioxide can rapidly diffuse.

Grave’s disease is due to excess secretion of thyroid hormones (T₃ & T₄). Diabetes mellitus is due to hyposecretion of insulin from beta-cells of pancreas. Diabetes insipidus is due to hyposecretion of ADH from posterior pituitary. Addison’s disease is due to hyposecretion of hormone from adrenal cortex.

During micturition, parasympathetic stimulation causes the detrusor muscle to contract and the internal urethral sphincter to relax. The external urethral sphincter (sphincter urethrae) is under somatic control and is consciously relaxed during micturition. 

Detailed Solution:

Option A is right because, during micturition, parasympathetic stimulation causes the detrusor muscle to contract and the internal urethral sphincter to relax.

Option B is wrong because the muscles of the urinary bladder contract and do not relax. 

Option C is wrong because during micturition, the muscles don't show fatigue. 

Hence, the correctb option is A. 

(a) When circulating in the bloodstream and inactivated, neutrophils are spherical.
Once activated, they change shape and become more amorphous or amoeba-like and can extend pseudopods as they hunt for antigens.

(b) Eosinophil cells are 12 - 17 µm in diameter - larger than neutrophils, and about 3 times the size of a red blood cell. You can see that eosinophils only have two lobes to their nucleus.

(c) In blood, basophils are round, but the shape changes as they migrate into tissues. They generally have a multilobed nucleus and no evidence of nucleoli.
Basophils also have an abundance of condensed chromatin around the periphery of the nucleus.

(d) Monocytes are the largest type of white blood cells and can be up to 20µm in diameter.
They have a large eccentrically placed nucleus, which is kidney bean-shaped. They have abundant cytoplasm and some fine pink/purple granules in the cytoplasm.

(e) Lymphocytes can look like monocytes, except that lymphocytes do not have a kidney-bean shaped nucleus, and lymphocytes are usually smaller.
They have a small spherical nucleus and have abundant dark staining condensed chromatin. Not much cytoplasm can be seen, and it is basophilic (pale blue/purple staining).

In anaphase, the centromeres of chromosomes start to divide into two, forming daughter chromosomes with centromere in each. Daughter chromosomes are repulsive, so they migrate towards opposite poles. Spindle fibres attached to the centromeres shorten and pull the chromosomes to the poles.

• Platelets, also called thrombocytes, are cell fragments produced from megakaryocytes.
• Platelets can release a variety of substances most of which are involved in the coagulation or clotting of blood.

Root hairs in plants have a large surface area and are surrounded by water, soil and nutrients and due to large surface area root hairs absorb water for the growth of plants.

Hence, the correct option is A.
NCERT Reference: Topic “Regions of the Root” of chapter Morphology of Flowering Plants.

• Globulins are not present in the Glomerular filtrate.
• Glomerular filtrate is the fluid that is filtered from the blood in the glomeruli of the kidneys. 
• It contains water, electrolytes (inorganic salts), glucose, amino acids, urea, and creatinine. 
• However, globulins, which are a type of protein, are not typically found in the glomerular filtrate because they are too large to pass through the filtration barrier.

ANF (atrial natriuretic factor) is secreted by the atrial walls of the heart. It is responsible for a decrease in blood pressure. When the blood pressure is increased, ANF which is secreted dilates the blood vessels causing a decrease in blood pressure.

When the placenta is axial and the ovules are attached to it in a multilocular ovary, the placentaion is said to be axile, as in china rose, tomato and lemon. In these plants, the ovules are attached to a central column in the ovary, allowing for the development of multiple chambers within the ovary, each containing ovules.

During an injury, the blood platelets release thromboplastin which converts plasma protein prothrombin into thrombin in the presence of calcium ions. Thrombin then converts soluble plasma protein fibrinogen into fibrin which forms a meshwork by trapping red blood cells, thus forming a clot.

Thomas Addison was the first person who showed the relation between the secretion of the adrenal gland and Addison’s disease named after him.

The process of release of urine is called micturition and the neural mechanism causing it is called the micturition reflex.

I. Infants and toddlers can not control this reflex action, thus micturition is an involuntary action for them.

II. Adults and grown-up children can control the reflex process of micturition voluntarily to some extent.

Hence, both statements are correct.

- Statement (i): The instrument used for recording the heart's electrical events is indeed named an electrocardiograph.

- Statement (ii): In any ECG, the part of the baseline between any two deflections is actually called a segment, not an interval. Therefore, this statement is incorrect.

- Statement (iii): Abnormalities in the working of the heart can indeed change the wave pattern of an ECG. This is because different heart conditions can affect the electrical activity of the heart, leading to changes in the ECG wave pattern.

Therefore, the correct option is C

The symbols % and ⊕ are used to represent zygomorphic (bilaterally symmetrical) and actinomorphic (radially symmetrical) flowers, respectively.

Actinomorphic flower - star shaped or radial- that can be divided in to two identical parts by a plane passing through the center. and is represented by a plus sign contained within a circle.

Example, Hibiscus,Rosa etc

Zygomorphic flower: can be divided into identical halves only through a single plane, bilateral symmetry.

represent in floral formula as %

In our body, the neural and the endocrine system jointly coordinate and integrate all the activities of the organs so that they function in a synchronised fashion.

• The ascending limb of the loop of Henle is not permeable to water (H₂O). 
• The loop of Henle is a U-shaped structure in the nephron of the kidney that plays a crucial role in the formation of urine. 
• The ascending limb of the loop of Henle is responsible for reabsorbing ions like sodium (Na⁺), potassium (K⁺), and chloride (Cl^-) from the filtrate, but it is impermeable to water.

• The narrow tubes found inside the lungs are called bronchioles. 
• When we breathe, air travels from the nose or mouth, and goes down the trachea and reaches the part called the carina.
• From here the tube branches into two, creating two bronchi that lead to the left and right lung each.
• From there onwards, the bronchi split into smaller and smaller bronchioles until it terminates in the alveoli where gas exchange occurs.

Hence, the correct option is C.

NCERT Reference: Topic- Human Respiratory System” of chapter "Breathing and Exchange of Gases" of NCERT.