NEET Unit Test - 3 - NEET MCQ

A venturi meter is a device used to measure the flow rate of a fluid through a pipe. The venturi meter works on Bernoulli's principle, which states that for an incompressible, non-viscous fluid flowing through a pipe, the sum of the pressure energy, kinetic energy, and potential energy per unit volume remains constant.

5 × 4 × 10 + (h₁ - 5) × 10 = h₂ × 1 × 10
200 + 10h₁ – 50 = 10h₂
10h₂ - 10h₁ = 150
h₂ - h₁ = 15
h₂ + h₁ = 20 + 20 + 5 = 45
2h₂ = 60
h₂ = 30
h₁ = 15
h₂/h₁ = 30/15
h₂/h₁ = 2/1

Time taken by liquid drop to fall
S=ut+(1/2)​at²
t=√2(H−D)/​​g
Horizontal velocity of liquid =√2gD​
Range =√2(H−D)/g​​× √2gD​
Range =2√D(H−D)

If the sphere is "just" floating means the sphere is exactly immersed in water (or) the buoyant force acting on it is exactly equal to its weight. The cavity reduces the weight of the actual sphere but has no role in the buoyant force.

The correct answer is Option B.

Ca_(s) + O2_(g) + H2_(g) → Ca(OH)₂ , ΔHf = ?

Desired equation = eq (iii) + eq(i) - eq (ii)

ΔH_f = (−151.80)+(−15.26)−(−68.37)
ΔH_f = (-151.80)+(-15.26)-(-68.37)
ΔH_f = −235.43KCalmol⁻¹

As q = 0, we have adiabatic process.
V₁ = 100L and V₂ = 800L
T₁ = 300K and T₂ = not given
For NH₃, γ = 4/3
Applying TV^γ = constant
(300)(100)^4/3-1 = (T)(800)^4/3-1
T = 300/2 = 150K
W= nR(T₂-T₁)/γ-1
= 1×8.314×150/(4/3-1)
= 3714 J
= 900 cal

w (reversible) < w (irreversible) (for compression process)

• Work done is the area under the P−V curve. It can be seen in the curve above that the area under the P−V curve for irreversible compression of the gas is more than the area under the curve for reversible compression.
• Thus, work done for irreversible compression is more than that for reversible compression.

In endothermic reactions, the energy of reactants is less than that of the products. Potential energy diagram for endothermic reactions is,

Where Ea = activation energy of forwarding reaction

Ea' = activation energy of backwards reaction

ΔH = enthalpy of the reaction

From the above diagram,

Ea = Ea' + ΔH

Thus, Ea > ΔH

pH = 8.7 ⇒ pOH = 5.3
Basic Buffer

If volume of salt = V ml

• Blue Green algae, Green algae, and autotrophic plants are photosynthetic organisms. They carry out photosynthesis using sunlight, water, and carbon dioxide and produce carbohydrates and oxygen.
• Photosynthetic bacteria like purple bacteria or green sulfur bacteria carry out anoxygenic bacterial photosynthesis.
• However, they reduce hydrogen sulfide instead of water and elemental sulfur is evolved instead of oxygen.

Thus, the correct answer is 'Non-Evolution of O₂.'

Energy produced during light reaction is transferred to the dark reaction in form of ATP to fix the carbon dioxide in form of glucose.

Jan Ingenhousz's experiments with an aquatic plant showed that in bright sunlight, small bubbles containing oxygen were formed around the green parts of the plant, while in the dark, they did not. This demonstrated that sunlight is essential for the process by which plants release oxygen.

Pigments are substances that have an ability to absorb light, at specific wavelengths. The chlorophyll a pigment to absorb lights of different wavelengths.

The light-dependent transfer of electrons by chloroplasts in photosynthesis that results in the cleavage of water molecules and liberation of oxygen is called the Hill reaction. Hill reaction required ferricyanide.

Hill Reaction:

Fermentation is a kind of anaerobic respiration in absence of oxygen to produce ethanol and carbon dioxide gas. Dough kept overnight in warm place becomes soft and spongy due to carbon dioxide gas released during fermentation.

NAA prevents the fall of fruits.
NAA (Naphthalene acetic acid) is a synthetic auxin. It is produced artificially. It inhibits the abscission. It prevents the formation of a layer called an abscission layer which is formed between the organs like fruits, flowers, etc. and the stem.  It is a layer of dead cells which causes fruit fall. As NAA prevents the formation of this layer, so it prevents the fall of fruits.

• Development includes all the changes undergone by a living plant from seed emergence to death.
• Dedifferentiation is regaining the lost capacity of cells or tissues of plants to divide under special conditions.
• Redifferentiation is the further maturation of dedifferentiated cells thereby specializing for a particular function.
• Differentiation is the division and growth of cells in order to mature.

• Plasmodesmatal connections are not the characteristic cells of the phase of elongation, rather they represent the cells of the meristematic phase of growth.
• Some characteristics of the cells of the phase of elongation include increased vacuolation, cell enlargement and new cell wall deposition which gives strength to the existing cell wall.

Senescence also known as aging refers to the decrease in the functional capacity of an organism. This results in a cellular breakdown followed by metabolic failure. The death of cells followed by the death of plant part is seen in senescence. Thus the correct answer is option A.

Stomata open in response to light. In response to drought stress, plants synthesize the hormone abscisic acid (ABA), which triggers closing of stomatal pores. Therefore it is a correct match.
Gibberellic acid promotes growth and does not have any effect on leaf fall. Therefore it is not a correct match.
Cytokinins (CK) are a class of plant growth substances (phytohormones) that promotecell division or cytokinesis, in plant roots and shoots. Therefore it is a correct match.
Auxin induces rapid elongation growth of higher plants. The mechanism of auxinaction in the elongation growth acts on the cell walls. Therefore it is a correct match.

Chloroplasts are specialized subunits, in plant and algal cells. Their main role is to conduct photosynthesis, where the photosynthetic pigment chlorophyll captures  energy from sunlight and converts it into glucose with the help of various enzymes

The genetic predisposition or the genetic make up of a plant is an internal factor that affects the rate of photosynthesis. The arrangement of genes present in the plant is expressed in a certain way in different plants.

Microtubules are unbranched hollow tubules of indefinite length about 25 nm of thickness with 15 nm core and boundary formed of 13 helically arranged protofilaments of globular molecules of α and β tubulins. Microtubules grow from nucleating regions. Their tips can grow and shorten quickly. 
Microfilaments are double helical cylindrical rods or filaments of actin-like protein that occur in both muscular and nonmuscular eukaryotic cells.
As microtubules do not radiate out from ER as they radiate out from the centrioles during cell division.

So, the correct answer is option C.

Most skeletal muscles are attached to bones by bundles of collagen fibers known as tendons. A skeletal muscle refers to multiple bundles (fascicles) of cells joined together called muscle fibers. The fibers and muscles are surrounded by connective tissue layers called fasciae.

Hinge joint occurs between humerus and radioulnar.
A hinge joint is a common class of synovial joint that includes the ankle, elbow and knee joints. Hinge joints are formed between two or more bones where the bones can only move along one axis to flex or extend. The elbow is a hinged joint made up of three bones which are the humerus, ulna and radius.

• Myasthenia gravis is an autoimmune disorder which affects neuromuscular junctions.
• It leads to various degrees of weakness in skeletal muscles.
• The onset of myasthenia gravis can be sudden.

When someone drinks lot of water, the volume of bod fluid increases, thic switches off the osmoreceptors in the body and suppresses the ADH release.

Aldosterone is secreted by the outer layer of the adrenal gland. When aldosterone is present in the blood, all the Na⁺ in the filtrate is reabsorbed b the epithelial cells of DCT and collecting duct. Retaining Na⁺ raises the osmotic pressure of the blood and reduces water loss from the body.