MPTET Varg 1 Biology Mock Test - 3 - MPTET MCQ

हमेशा बहुवचन में प्रयुक्त होने वाला शब्द है: 'अमीर'।

• उदाहरण- वह अमीर है, वे अमीर हैं।
• दोनों में प्रयुक्त हो सकता है।

स्पष्टीकरण
अन्य विकल्प
सामग्री - एकवचन शब्द का वाक्य प्रयोग – हवन के लिए सामग्री कम पड़ेगी।
बहुवचन शब्द का वाक्य प्रयोग – पूजा के लिए सभी आवश्यक सामग्री आ गई है।
नारी - एकवचन शब्द का वाक्य प्रयोग – नारी की अवहेलना भगवान का अपमान है।
बहुवचन शब्द का वाक्य प्रयोग – आज की नारियाँ पुरुषों से किसी मामले में कम नही।
अन्यसंबंधित बिंदु

The correct answer is "weak"
Explanation

• Weary refers to being exhausted, tired, or fatigued, both physically or mentally. It can also refer to being discouraged, skeptical or skeptical about something.
  • Example: "The marathon runner felt weary after running for 26 miles."

Let's see the meanings of the given words

• Careless refers to being negligent or not paying attention to details, which often results in mistakes or accidents. It also means someone who is not taking responsibility or not being cautious.
  • Example: The careless driver caused an accident by running a red light."
• Shivering refers to a physical reaction characterized by rapid, small, involuntary muscle contractions that results in a trembling of the body, usually as a response to cold or fear. 
  • Example: "The shivering child was wrapped in a blanket to keep warm."
• Troubled refers to being in a state of distress, anxiety, or difficulty. It can also refer to a person who is experiencing personal or emotional problems.
  • Example: "The troubled economy was causing widespread unemployment."
• Weak refers to something that is lacking in strength, power, or force, or something that is not substantial or effective. It can also refer to a person who is not physically or mentally strong.
  • Example: "The weak connection caused the internet to drop frequently."

According to the meanings of the given words, the correct answer is Option 4, i.e., weak.

The erroneous part is 'the workers gets'.

Explanation

• The given sentence is grammatically incorrect.
• Here, 'the workers get' should be used instead of 'the workers gets'.
• According to the “Subject-Verb Agreement Rule”, a singular subject always takes a singular verb and a plural subject always takes a plural verb.
• In the given sentence, ‘workers’ is a plural subject that will take ‘get’ as a plural verb.
• Thus, the correct answer is Option 4.
  

Correct Sentence: Every Saturday, the workers get their weekly wages.

The correct answer is Indore.

Explanation

• Madhya Pradesh's first bone bank is being set up at MGM Medical College, Indore.​
  • The bone bank is like an eye bank.
  • In this, the bones donated by the donor or removed during the operation are kept in a deep freezer at a temperature of -40 to -80 degrees Celsius.
  • Before this, the bones to be preserved are thoroughly tested for antigens, and infections.
  • And they are used after keeping them in a deep freezer for six months.
  • Bones broken in an accident or accident can also be replaced from a 'bone bank'.​

The correct answer is Malwa.

Explanation

• The Malwa Plateau forms the water divide between the Ganga and Narmada basin.
• Malwa Plateau, plateau region in north-central India.
• It is bounded by the Madhya Bharat Plateau and Bundelkhand Upland to the north, the Vindhya Range to the east and south, and the Gujarat Plains to the west.
• The western part of the region is drained by the Mahi River, the middle section by the Chambal River, and the eastern part by the Betwa River and the headwaters of the Dhasan and Ken rivers.

Other Related Points The Ganga:

• The Ganga basin covers about 8.6 lakh sq. km area in India alone.
• The Ganga river system is the largest in India having a number of perennial and non-perennial rivers originating in the Himalayas in the north and the Peninsula in the south, respectively.
• The Son is its major right-bank tributary.
• The important left-bank tributaries are the Ramganga, the Gomati, the Ghaghara, the Gandak, the Kosi and the Mahananda.
• The river finally discharges itself into the Bay of Bengal near the Sagar Island.

Narmada River:

• The Narmada river originates from the Narmada Kund located in Amarkantak, Anuppur district in Madhya Pradesh.
• Amarkantak is located on the Maikal mountain.
• The Narmada river forms the unmarked boundary between North and South India.
• The major tributaries of the Narmada are Barna, Tawa, Kanar, Kolar, Man, Hatni, Uri, Shakkar, etc.
• It flows westwards (1, 312 km) before falling into the Gulf of Khambhat.
• The Narmada river is the longest river in Madhya Pradesh and it's called "The Lifeline of Madhya Pradesh".
• The waterfalls created by the Narmada River include Kapil Dhara and Dudh Dhara Falls (Anuppur), Dhuandhar Falls (Bhedaghat, Jabalpur), Sahasradhara Falls (Maheshwar, Khargone), Dardhi Falls, Manadhata Falls, etc.

The total number of teachers are shown by coloured portion in the venn diagram-

The total number of teachers are - 9 + 44 + 51 + 46 + 21 = 171
Hence, the correct answer is 171.

CCE refers to a school-based evaluation, which covers all aspects of school activities related to a child’s development. It emphasizes two-fold objectives such as continuity of evaluation and assessment of learning outcomes in a comprehensive manner.

Explanation

• The ‘continuous’ aspect of CCE takes care of ‘continual’ and ‘periodicity’ features of assessment.
• The 'comprehensive’ elements of CCE take care of the assessment of the all-round development of the child’s personality.
• Comprehensive evaluation includes both Scholastic as well as Co-Scholastic aspects of the pupil’s growth.
• Scholastic aspects cover curricular areas or subject-specific areas, while co-scholastic aspects consist of Life Skills, Co-Curricular Activities, Attitudes, and Values.

Thus, it is concluded that the Meaning of comprehensive evaluation in a continuous and comprehensive evaluation is evaluation of educational and co-educational field.

• The respiratory Quotient is defined as the ratio of the volume of CO₂ liberated for the volume of O₂ consumed.
• RQ = CO₂ eliminated / O₂ consumed.
• The value of R.Q. depends upon the type of respiratory substance utilized & measured by the device Ganong’s respirometer.

• Anaerobic respiration occurs in the absence of oxygen. zero moles of oxygen are consumed during the reaction.
• So, the respiratory quotient in anaerobic respiration is infinite (∞)
• 2 CO₂/ 0 O₂ = ∞

Other Related Points

• The R.Q. of Carbohydrates is 1

C₆H₁₂O6 + 6O₂ +6H₂O 6CO₂ + 12H₂O + E

• The R.Q. of fats/oils is 0.70 or R.Q.<1
• The R.Q. of proteins is 0.8 or 0.9 or <1
• The R.Q. of organic acids such as malic acid is more than 1 or >1

Kary Mullis was awarded the Nobel Prize in Chemistry (1993) for the invention of the Polymerase Chain Reaction Technique.

Concept:

• PCR involves in vitro amplification of the gene of interest using a PCR machine (Thermal cycler).
• This technique can generate millions to billions of copies of the desired segment of DNA with high accuracy and specificity.
• The PCR machine (Thermal cycler) is completely automated and involves automatic thermal cycles for the denaturation and renaturation of double-stranded DNA molecules.
• Requirements for PCR:
  • The desired segment of DNA to be amplified
  • Four deoxyribonucleoside triphosphates (dNTPs): dATPs, dGTPs, dTTPs, dCTPs
  • Primer molecules
  • Thermostable DNA polymerase (Taq polymerase: Enzyme isolated from Thermus aquaticus)
  • Mg⁺⁺ ions

Steps in PCR:

1. Step I: Denaturation
   • The reaction mixture is heated to 90^oC–95^oC to denature double-stranded DNA to single strands.
2. Step II: Annealing
   • The mixture is allowed to cool (55^oC–65^oC) to allow the primers to anneal their complementary sequences at the two ends of the target sequences.
3. Step III: Extension / Polymerization
   • The temperature of the reaction mixture is again raised to 70^oC–72^oC.
   • This allows thermostable Taq polymerase is used to extend the primers, using the four nucleoside triphosphate precursors to make new complementary copies of the two template DNA strands.

Other Related Points

Herbert Boyer:

• In 1969, Herbert Boyer performed studies on restriction enzymes of the E. coli bacterium with especially useful properties.
• Boyer observed that these enzymes have the capability of cutting DNA strands in a particular fashion i.e., DNA has ‘sticky ends’ on the strands.
• These clipped ends made ligating the pieces of DNA a precise exercise.

Har Gobind Khorana:

• In 1966, H. Gobind Khorana and his coworkers used long, artificial mRNA molecules containing only one nucleotide repeated continuously, or different nucleotides in repeating patterns.
• The researchers added each artificial mRNA to ribosomes in a test tube and studied the sequence of amino acids in the polypeptide chain made by the ribosomes.
• Khorana’s method, combined with the results of Nirenberg and Leder experiments, deciphered all the 64 codons in the dictionary of genetic code.
• Nirenberg and Khorana received a Nobel Prize in 1968 for their research in solving the genetic code.

Arthur Kornberg:

• Arthur Kornberg, a prolific researcher discovered DNA polymerase, an enzyme critical to DNA replication.
• For this discovery, Arthur Kornberg shared the 1959 Nobel Prize in Physiology or Medicine with Severo Ochoa, who discovered RNA polymerase.

Key Points

• Voice is produced due to the vibration of the vocal cords.
• Vocal cords are a pair of tissue that stretches at the top of the trachea.
• Vocal cords are enclosed in the thyroid cartilage.
• The cords, muscles and cartilages together form the larynx or the voice-box.

Explanation

• When we try to produce sound or speech, the lungs blow air against the cords in a nearly-closed position.
• As air tries to push through the small space, it makes the cords vibrate.

Other Related Points

• Ligaments - are bands of connective tissue that help to connect bones and joints.
• Tendons - are fibrous connective tissue that connects muscles to bones.

The correct answer is option 4.

Explanation

• The musculoskeletal system in the body comprises of bones and muscles.
• The muscles are connective tissues formed of bundles of muscle fibres (myofibrils) called fasciculi.
• Muscles are innervated by the nerve fibers and undergo contraction.
• The primary functions of a muscle are:
  • facilitation of movement
  • maintenance of body posture
  • transportation of blood through the body
  • peristaltic movement of the alimentary canal
• On the basis of structure and function, muscles are classified into Striated and Unstriated muscles.

Important Points

​Structure of the striated muscles:

• ​These muscles appear striated due to the presence of its functional unit, called the sarcomere.
• Each muscle cell or myocyte contains myofibrils composed of actin and myosin myofilaments repeated as a sarcomere.
• Actin and myosin are cellular motor proteins that facilitate contraction of muscles, to effectively bring about movement.
• In addition to actin and myosin, another protein called troponin is also present in the sarcomere.
• The sarcomere's striated appearance arises from the presence of two bands - A band and I band.
• The A band is a thick, dark region composed of myosin filaments while the I band is the thin, lighter band composed of actin filaments.
• The ends of the sarcomere are marked by the presence of a Z-line.
• Actin filaments are anchored to the Z-line.
• The central region of the sarcomere contains only myosin filaments and is a zone called the H-band.
• A thin line called the M-line passes through the H-band.
• Calcium is the ion that facilitates muscle contraction.
• The H-band is crucial in anchoring the myosin filaments to the central region of the sarcomere.
• Two anchoring cytoskeletal proteins, called obscurin and myomesin present in the H-band are responsible for anchoring the myosin to the sarcoplasm.
• While myosin and actin are both muscular proteins that facilitate movement, not both are able to bind ATP.
• Myosin binds ATP and utilizes the released energy to move actin filaments.
• Tropomyosin is a protein that blocks myosin-binding sites on actin filaments.
• Troponin undergoes confirmational change upon binding with calcium to move tropomyosin.
• This unblocks the myosin-binding sites on actin filaments.
• As a result, the head of the myosin filament binds to the actin-binding site forming an actin-myosin cross-bridge, thereby initiating muscle contraction.

Concept -
Bentham and Hooker system of classification:

• George Bentham and Joseph Dalton Hooker, both of whom were closely involved with the Royal Botanic Garden at Kew, England, provided a systematic classification of the plant kingdom, notably the Angiosperms.
• In their famous work Genera Plantarum, which was published in three volumes between the years 1862 and 1883, they developed an amazing system of categorization for Phanerogams.
• It is a natural classification system.
• The Plant Kingdom was separated into two sections by Bentham and Hooker: Cryptogamia (non-flowering plants) and Phanerogamia (flowering plants) (flowering plants).
• Dicotyledon, Gymnosperm, and Monocotyledon are the three classes that make up the Phanerogamia division.
• Outline of the Bentham and Hooker Classification is provided below in the figure -

Explanation -
The given four statements are -

1. Angiosperms are divided into Gyrmnospermae and Dicots - False
   • Angiosperms or phanerogams or spermatophytes are divided into Dicotyledons, gymnosperms and monocotyledons.
2. Polypetalae has - Thalamiflorae, Calycifiorae and Monochlamydeae, as series - False
   • Polypetalae is divided into the following series - Thalamoflorae, Disciflorae and Calyciflroae.
3. Gamopetalae includes series - Gentianales, Polemoniales, Personales and Lamiales - False
   • Gampetale includes Inferae, Hetermorea and bicrpellatae as its 3 series.
4. Polypetalae, Gamopetalae and Monochlamydeae are placed phylogenetically - True
   • They are placed phylogenetically.
   • Bentham and Hooker were committed to placing the classes and sub-classes according to their evolutionary relationships.

As statement 4 is tr ue, the correct answer to this question is - Polypetalae, Gamopetalae and Monochlamydeae are placed phylogenetically.​

Concept:

• The acrosome is present in the sperms head
• Acrosome secretes hydrolytic enzymes that bind with corona radiata and brings changes in the zona pellucida. This process is called acrosomal reaction.
• When the outer acrosomal membrane fuses with the plasma membrane and acrosomal enzymes responsible for penetration of the zona pellucida are released the acrosome reaction occurs.
• It helps the sperm to penetrate the egg's coats and prevents polyspermy.

​
Explanation:
Option (1) Its contact with zona pellucida of the ova - Correct

• As an acrosomal reaction occurs when it comes in contact with zona pellucida of the ova so it is the correct option.

Option (2) Reactions within the uterine environment of the female - Incorrect

• It does not react in the uterine.
• So, this is an incorrect option

Option (3) Reactions within the epididymal environment of the male - Incorrect

• Acrosome do not react with the male reproductive system, it only starts reacting in the female reproductive system
• So, this is an incorrect option

Option (4) Androgens produced in the uterus - Incorrect

• Production of androgens does not occur in the uterus.
• So, this is an incorrect option.

So, the correct option is Option 1.

• The mammalian kidney consists of numerous tubular structures called nephrons.
• Each nephron has 2 parts:
  • Glomerulus - is a tuft of capillaries that takes part in the first step of urine formation, i.e. glomerular filtration.
  • Renal Tubule - starts with the Bowman's capsule, continues as proximal convoluted tubule(PCT), Henle's loop and the distal convoluted tubule(DCT).
• The glomerulus together with Bowman's capsule is called malpighian or renal corpuscle.
• Glomerulus:
  • It helps in filtration of blood through 3 layers of cells - endothelium of glomerular blood vessels, epithelium of Bowman's capsule and the basement membrane between the two layers.
  • The epithelial cells of Bowman's capsule are called podocytes.
  • Podocytes are intricately arranged such that there are minute pores in between, which are called filtration slits or slit pores.
• Proximal Convoluted Tubule:
  • It helps in maintaining the pH and ionic balance of the body fluids.
• ​Loop of Henle:
  • The loop of Henle has two limbs - the descending limb and the ascending limb.
  • As the glomerular filtrate moves in opposite directions along the two limbs of Henle's Loop, it gives rise to a counter-current mechanism, which is responsible for concentrating the urine.
  • Minimum reabsorption takes place.
  • It plays important role in maintenance of high osmolarity of medullary interstitial fluid.
  • It helps in concentrating the urine so that water is conserved in the body.
• Distal Convoluted Tubule:
  • There is conditional reabsorption of water and Na+.
  • It helps in maintaining the pH and sodium-potassium balance in blood.

Important Points
Urine formation involves 3 major processes:

• Glomerular Filtration - The glomerular capillary blood pressure causes the filtration of blood through the 3 layers. It is also called ultrafiltration because blood is finely filtered through the podocytes such that all plasma contents except proteins pass onto the lumen of Bowman's capsule.
• Reabsorption - The GFR is about 4.5 times that of the urine output, suggesting that almost 99% of the filtrate is reabsorbed by the renal tubules by active or passive mechanisms.
  • PCT - actively reabsorbs all of glucose, 75% of amino acids & Vitamin C, 90% of bicarbonate (HCO₃^-), 70% of Na⁺, 75% of K⁺ and huge amount of Ca²⁺ from the glomerular filtrate. This makes for the reabsorption of almost 80% of the total glomerular filtrate.
  • Ascending Limb of Henle's Loop - actively reabsorbs about 25% of K⁺ and some Cl^-, while some Na⁺ is reabsorbed by diffusion.
  • DCT & Collecting Tubules - reabsorb some Na⁺ from filtrate in exchange of K⁺ from interstitial fluid.
• Secretion - The tubular cells secrete substances like H⁺, K⁺ and ammonia into the filtrate. It is an important step because it helps in maintaining ionic balance of body fluids.

Other Related Points

• Renal plasma flow - is the amount of plasma (blood) that passes through the glomerulus of all the nephrons in both the kidneys per minute.
• Cardiac output - is the amount of blood pumped by the heart in a minute.

Cardiac output = Stroke volume (Blood pumped by each ventricle per minute) × Heart Rate

• About 1000-1200ml of blood or 650ml of blood plasma is the renal plasma flow, which is one-fifth of the cardiac output.
• Glomerular Filtration Rate (GFR) - is the amount of blood filtered out of the glomerulus and is clinically used to diagnose kidney diseases.
• The GFR for a healthy individual is about 125ml/min or 180L per day.
• Urine output - is the amount of urine excreted from the body per day and is about 1.5L on an average.

• Catalytic converters are used in vehicles to reduce emission of pollution causing gases.
• They may use Platinum, Palladium and Rhodium as catalysts.
• The exhaust passes through the catalyst chamber and converts unburnt hydrocarbons into CO₂ and steam (H₂O).
• Carbon monoxide (CO) and nitrogen oxides are converted to CO₂ and N₂ respectively.
• Pollutants like unburnt hydrocarbons, CO and nitrogen oxides are formed by the incomplete combustion of fuel in the vehicles.

Other Related Points

• Lead, in the fuel petrol, inactivates the catalyst of the catalytic converters by getting deposited on it.
• This prevents the exhaust gases to come in contact with the catalyst, making it useless.
• Thus, vehicles using catalytic converters should use unleaded petrol.

Concept:

• Loss of biodiversity can be caused due to a number of factors but has been accelerated by several human activities.
• Several species have become extinct in just the last century.
• We are currently in the phase of the 'Sixth extinction', which is happening at a much faster rate than the previous mass extinctions.
• The previous extinctions happened in pre-human era, thus proving that human activities are responsible for the higher rate of extinction.
• The major causes for loss of biodiversity is referred to as the 'Evil Quartet'.

Important Points

• Passenger pigeon is an extinct species of pigeon that was native to North America.
• It was a migratory bird that nested in large flocks, which made them more vulnerable.
• It was once considered to be the most abundant bird in the entire world.
• They were hunted for their meat and their overexploitation made them extinct.

Other Related Points

Evil Quartet -

• Habitat Loss & Fragmentation -
  • Loss of habitat may be caused by human activities which require more land area.
  • Forest areas are cleared for urbanisation and infrastructural developments.
  • This is the reason tropical forests have reduced to 6% from 14% of total land surface.
  • For example, Amazon rainforests are increasingly being cleared for cultivation of soya beans and conversion to grasslands for raising beef cattle.
  • Some of the habitat loss is also caused due to increasing levels of pollution.
  • Fragmentation refers to the breaking up of a large area into smaller fragments of habitats.
  • For example, if a road is built across a forest, the forest gets divided into at least 2 different fragments of habitat.
  • This also increases the perimeter area, which reduces the habitat area even further.
• Overexploitation -
  • This refers to the overuse and overexploitation of living organisms for human needs.
  • Example - Passenger pigeon, Stellar's sea cow.
  • Marine fishes are highly over-harvested for consumption as well as for obtaining other products like fish oils, etc.
• Alien Species Invasion -
  • When any species from a different habitat (alien species) is introduced into another habitat, it tends to grow exponentially in absence of its natural predator.
  • This reduces the resources available for the native species of that habitat.
  • The native species present in the habitat are not equipped to compete with these alien species and hence, face a threat of extinction.
  • For example, introduction of Nile perch in Lake Victoria in east Africa led to the extinction of more than 200 species of cichlid fishes there.
  • Illegal introduction of African catfish Clarias gariepinus for aquaculture has posed a threat to the indigenous catfishes in Indian rivers.
• Co-extinction -
  • When two species live in obligatory associations, extinction of one species leads to the extinction of another.
  • Example - Host fishes and their parasites, co-evolved plant-pollinator mutualistic species.

Concept:

• The ability of the human body to fight against the different pathogenic organisms or the toxins that they release that damage the tissues and organs are called immunity.
• When the immune system undergoes overdrive and starts attacking the body's own cells. This condition is referred to as an autoimmune disorder.
• In autoimmune disorders, due to some trigger, the immune system starts producing antibodies.
• These antibodies instead of fighting pathogens start attacking the body's own cells.
• Treatment involves reducing immune system activity.
• E.g.: Rheumatoid arthritis, Multiple sclerosis, Guillain-Barre syndrome, Grave's disease, Myasthenia gravis, etc.

Explanation:​​

Myasthenia gravis -

• It is an autoimmune disease.
• It is a chronic disease that affects the muscles.
• In this disorder, antibodies bind to the nerve making it unable to stimulate the muscles. As a result, skeletal muscles are weakened.
• It affects the voluntary muscles of the body such as those of the eyes, mouth and limbs.
• Symptoms:
  • Weakness in eye muscles
  • Blurred vision
  • Change in facial expression
  • Shortness of breath and trouble swallowing
  • Weakening muscles
  • Trouble in walking
  • Fatigue

Other Related PointsOsteoporosis -

• ​Osteoporosis is a disease that makes bones weak and brittle.
• Causes:
  • Diet with low calcium
  • Severe restrictions on food intake
  • Lack of exercise
  • Low levels of estrogen in women after menopause is known to cause osteoporosis in women.
  • Medical conditions such as intestinal problems, kidney diseases and parathyroid & thyroid problems.
  • Smoking and alcohol abuse.
• Symptoms include back pain, loss of height over the time, stooped posture and fragile bones.

Arthritis -

• Arthritis refers to a disease associated with swelling or pain in joints.
• There are several types of arthritis. Some of these are osteoarthritis, rheumatoid arthritis, gout, etc.
• Common arthritis causes are ​age, wear and tear of a joint, injuries, obesity, autoimmune disorders as in the case of rheumatoid arthritis, and muscle weakness.
• ​Symptoms include pain, swelling in joints, stiffness and loss in range of motion.

Muscular dystrophy -

• Muscular dystrophy refers to diseases that affect muscle mass.
• It causes progressive weakness and loss of muscle mass.
• Causes:
  • Muscular dystrophy occurs due to mutations in genes.
  • The abnormal genes do not produce proteins that are needed for the formation of healthy muscles.
  • Deletion in the DMD gene (dystrophin gene) causes Duchenne and Becker muscular dystrophy.
• Symptoms include muscle pain and stiffness, delayed growth, large calf muscles, frequent falls, difficulty in getting up from lying position, trouble in running and jumping, etc.

So the correct answer is option 3 (Myasthenia gravis).

Concept:

• Krebs cycle is also known as the tricarboxylic acid cycle.
• It takes place inside the mitochondrial matrix after glycolysis. It is an important part of aerobic respiration.

Explanation:
Option 1:

• Krebs cycle starts with the condensation of acetyl co-enzyme A with oxaloacetic acid (4-carbon compound) to form citrate.
• This reaction is catalyzed by citrate synthase and coenzyme is released.

Option 2:

• There are three steps at which NAD⁺ is converted to NADH and H⁺.
• Firstly, Isocitrate undergoes dehydrogenation and decarboxylation to form 5 carbon ?-ketoglutarate with the formation of NADH.
• ?-ketoglutarate undergoes oxidative decarboxylation to form succinyl CoA, a 4-carbon compound with the formation of NADH.
• Malate is dehydrogenated to form oxaloacetate with the formation of NADH.

Option 3:

• Succinate is oxidized into fumarate with the formation of FADH2 from FAD.
• This reaction is catalyzed by succinate dehydrogenase.

Option 4:

• Succinyl CoA forms succinate using an enzyme succinyl CoA.
• This is coupled with substrate-level phosphorylation with the formation of GTP.

​​
So, the correct answer is option 1.

Correct Answer: Option 4

Explanation:

• Diuresis is a condition wherein kidneys produce more urine than the usual amount.
• ​Diuresis can be controlled by the release of ADH that results in more absorption of water in the nephrons resulting in lesser urine output.

Anti-Diuretic Hormone (ADH) or vasopressin :

• ADH is a hormone that is secreted by the neurohypophysis region of the pituitary gland.
• ADH is secreted in response to an increase in osmotic pressure of the blood which is due to the loss of water from the body.
• ADH stimulates the DCT of nephrons to reabsorb more water thus making the urine concentrated.
• It is also a vasoconstrictor and is released in response to low blood pressure.

Renin:

• ​Renin is a hormone released by the cells of the Juxtaglomerular apparatus (JGA) of the kidney.
• It is released in response to low blood pressure.
• Renin acts on Angiotensinogen and converts it into Angiotensin I.
• Angiotensin I is then converted to Angiotensin II by the Angiotensin-converting enzyme (ACE).
• Angiotensin II in turn acts as a vasoconstrictor and increases blood pressure.
• It enhances the reabsorption of Na⁺, Cl^- and water.
• It also stimulates the release of aldosterone from the adrenal cortex.

Aldosterone:

• ​Aldosterone is a hormone secreted by the adrenal cortex in response to the renin-angiotensin II- aldosterone system.
• It stimulates DCT and collecting ducts to reabsorb more Na⁺ and water and thus increases the blood pressure and volume.

Atrial natriuretic factor:

• ​Atrial Natriuretic Factor (ANF) is released by the atrial walls of the heart in response to increased blood volume and increased blood pressure.
• ANF acts on kidneys by inhibiting the reabsorption of Na+ and Cl- ions from the collecting duct.
• It also inhibits the release of renin, ADH, and aldosterone.
• This leads to a condition called natriuresis (increased excretion of Na+ in urine) and diuresis.

Option 1: Atrial natriuretic factor causes vasoconstriction​​​

• This statement is wrong because ANF causes vasodilation and results in diuresis.

Option 2: Decrease the secretion of renin by JG cells

• ​A decrease in the secretion of renin by JG cells will result in more loss of water in the urine leading to diuresis.

Option 3: More water reabsorption due to under secretion of ADH

• ​This statement is again wrong.
• ADH secretion causes reabsorption of water in DCT and collecting duct.
• While secretion will result in loss of water in the urine and lead to diuresis.

Option 4: Reabsorption of Na⁺ and water from renal tubules due to aldosterone

• ​This statement is correct.
• Secretion of aldosterone helps in the reabsorption of Na⁺ and water by the kidneys thus helping in preventing diuresis.

So the correct answer is option 4.

Concept:

• Cells grow and multiply to form a diversity of life forms, this process of growth and multiplication of cells is called Cell Division.
• Cell division is of three types:

1. Mitosis - Equational division, occurs in somatic (non-sex) cells
2. Meiosis - Reductional division, occurs in sex cells
3. Amitosis - Direct type of division, occurs in prokaryotes

Explanation:

• Meiosis can be further divided into two stages - Meiosis I and Meiosis II
• Meiosis I has 4 phases Prophase I, Metaphase I, Anaphase I & Telophase I
• Similarly, meiosis II also has 4 phases Prophase II, Metaphase II, Anaphase II & Telophase II
• Anaphase II is characterized by the simultaneous splitting of the centromere of each chromosome (which was holding the sister chromatids together), allowing them to move toward the opposite pole of the cell.

Mistake Points

• Anaphase I is often confused with Anaphase II, during anaphase I chromosomes gets segregated and division of centromere is absent whereas in anaphase II, centromere split and chromatids move towards the opposite pole

Other Related Points

Concept:

• The monocot leaf is called the isobilateral leaf.
• It is oriented parallel to the main axis of the plant and also, parallel to the direction of sunlight.

Explanation:
​Let us look at the anatomy of the isobilateral leaf:

• The stomata are present on both surfaces of the epidermis.
• The mesophyll is not differentiated into palisade and spongy parenchyma.
• In grasses, the adaxial epidermal cells that are present along the leaf vein get modified into large, empty, and colorless cells.
• These cells are called bulliform cells.
• When bulliform cells have absorbed water and are turgid, the leaf surface is exposed.
• When bulliform cells undergo water stress (especially during dry weather conditions), they become flaccid (lack turgidity and are not swollen).
• In this condition, the leaf surface curls inwards to avoid loss of water.

Figure: T.S of monocot leaf
So, the correct answer is option 2, Flaccidity of bulliform cells.
Other Related Points

• Conditions like water stress, high temperatures, and high carbon dioxide concentration can cause the stomata to close.
• The intercellular air spaces in the spongy mesophyll layers allow the diffusion of carbon dioxide and oxygen.
• Tyloses form in the xylem vessels in conditions like an invasion by pathogenic microbes or during conditions of water stress
  

Explanation:

C₂ Cycle or Glycolate cycle or Photorespiration -

• The light-dependent uptake of oxygen and release of carbon dioxide in C3 photosynthetic cells is called photorespiration or Glycollate cycle.
• Photorespiration occurs because Rubisco acts as oxygenase at a higher concentration of oxygen and a low concentration of carbon dioxide in C3 plants.
• In C3 plants some O2 does bind to RuBisCO, and hence CO₂ fixation is decreased. Here the RuBP instead of being converted to 2 molecules of PGA binds with O2 to form one molecule of phosphoglycerate and phosphoglycolate (2 Carbon) in a pathway called the Glycollate pathway
• It is a wasteful process. Because not linked with ATP and NADPH generation instead it results in the release of CO₂ with the utilisation of ATP
• It occurs in chloroplast, peroxisome, and mitochondria.

Other Related Points

• Calvin-Benson Cycle or Calvin Cycle or C3 Cycle: The cycle was discovered in 1950 by Melvin Calvin, James Bassham, and Andrew Benson.
• It is called C3 Cycle because the first stable compound formed is a 3 carbon molecule PGA
• The Calvin cycle can be described under three stages: carboxylation, reduction, and regeneration.
• TCA Cycle: commonly-known as Kreb's cycle occurs in the matrix of mitochondria. All the enzymes of the TCA cycle or Krebs cycle are present in the matrix of mitochondria except marker enzyme succinic dehydrogenase, which is present on the inner mitochondrial membrane.

Concept-

• In sexual reproduction, it is very important to have a female reproductive system and a male reproductive system for the production of offspring, because the zygote is formed as a result of the fertilization of sperm and egg, and new offspring are formed from it.

The following are the major parts of the female reproductive system:-

• Ovary 1 pair
• Uterus
• Fallopian tube
• Vagina

The main external structures of the female reproductive system include:
Labia Majora:-

• The labia majora ("large lips") surround and protect the other external reproductive organs.
• During puberty, hair growth occurs on the skin of the labia majora, which also contains sweat and oil-secreting glands.

Labia Minora:-

• The labia minora ("small lips") can come in a variety of shapes and sizes.
• They lie inside the labia majora, open the vagina (the canal that joins the lower part of the uterus to the outside of the body) and surround the urethra (the tube that carries urine from the bladder to the outside of the body). Is ).
• This skin is very delicate and can easily become irritated and inflamed.

Bartholin's Glands:

• These glands are located next to the vaginal opening on each side and produce a fluid (mucus) secretion.
• These glands secrete fluid that helps lubricate the vagina. Sometimes the openings of these glands become obstructed, allowing fluid to back up into the gland.
• The result is a relatively painless swelling called a Bartholin's cyst.

Clitoris:-

• The two labia meet at the minor clitoris, a small, sensitive protrusion that in males is the equivalent of the penis.
• The clitoris is covered by a fold of skin called the prepuce, which resembles the foreskin at the end of the penis.
• Like the penis, the clitoris is very sensitive to stimulation and can become erect.

Internal reproductive organs include:

Vagina:-

• The vagina is a canal that connects to the cervix (the lower part of the uterus) on the outside of the body. It is also known as the birth canal.

Uterus (womb):-

• The uterus is a hollow, pear-shaped organ that is home to the developing embryo.
• The uterus is divided into two parts: the cervix, which is the lower part that opens into the vagina, and the main body of the uterus, called the corpus.
• The corpus can easily hold a developing baby. A canal through the cervix allows sperm to enter and menstrual blood to exit.

Ovary:-

• The ovaries are small, oval-shaped glands located on either side of the uterus.
• The ovaries produce eggs and hormones.

Fallopian tube:-

• These are narrow tubes that are attached to the upper part of the uterus and serve as a pathway for ova (egg cells) to travel from the ovary to the uterus.

Concept:

• Neurons are the functional and structural units of the nervous system.
• Neurons transmit nerve impulses from the effector to the receptor.
• They are composed of three major parts, namely cell body, axon, and dendrites.
• Based on the number of axons and dendrites, the neurons are divided into three types - multipolar, bipolar, and unipolar.

Explanation:

• Bipolar neurons are the neurons that contain one axon and one dendrite.
• The cell body is present at the center, from which there are two extensions towards opposite poles.
• One extension forms the axon and the other forms the dendrite on the opposite pole.
• They transmit gradual signals to the brain and play important role in the sensory pathway and perception of sight.
• Bipolar neurons are found in the retina of the eyes.

Hence, the correct option is Option (3) Retina.

Concept:

• Ecological succession - the gradual change in the species composition of a given area caused due to successive colonization of different groups or communities of plants.
• Sere or seral stage - refers to the individual transitional communities that successively change in a given area.
• Succession can be of 2 types:
  • Primary - It starts in areas where no living organisms ever existed. Example - Bare rocks, cooled lava.
  • Secondary - It starts in areas where organisms existed previously, but is not present currently. Example - Flooded land, burned forest.
• Primary succession requires the formation of soil and hence is a much slower process than secondary succession.

Important Points

• For primary succession to take place, a bare area needs to be colonized first.
• Pioneer species -
  • They are species that can invade and colonize a bare area.
  • They have the ability to survive with minimum resources.
  • These also cause modifications of the habitat such that successful establishment of the next seral stage species becomes possible.
• Climax community -
  • It denotes a stable community that stays in equilibrium with the environment.
  • The equilibrium shifts only when the environment changes.
  • It is usually represented by a forest community.
• Depending on the place of origin, primary succession can be:
  • Hydrarch - Starting from wet areas or hydric conditions. Example - Newly formed lake.
  • Xerarch - Starting from dry areas or xeric conditions. Example - Bare rocks.

Explanation:

• Both hydrarch and xerarch successions proceed towards a mesic condition to reach the climax community.
• Though the climax community is same for both hydrarch and xerarch successions, the pioneer species are different:
  • Lichens form the pioneer species for xerarch succession.
  • Lichens have the ability to colonize barren rocks.
  • They also secrete acids to dissolve rocks, leading to weathering and formation of soil.
  • Phytoplankton is the pioneer species for hydrarch succession.
  • These organisms are autotrophic and does not require much nutrients.
  • These facilitate the establishment of the later stages like submerged or floating plants.

Therefore, the pioneer species in xerarch and hydrarch succession are respectively lichens and phytoplankton.

The correct answer is 1 only.

• The term ‘Founder effect’, in population genetics, is used to indicate reduced genetic variation as compared to the original population.

Explanation

• The term "founder effect" refers to the observation when a small group of individuals breaks off from a larger population and establishes a new population.
  • The particular alleles may not be representative of the larger population.
  • As the new population grows, the allele frequencies will usually continue to reflect the original small group.
• A founder effect occurs when a new colony is started by a few members of the original population.
• This small population size means that the colony may have:
  • reduced genetic variation from the original population.
  • a non-random sample of the genes in the original population.

Important Points

• A population bottleneck or genetic bottleneck is a sharp reduction in the size of a population.
  • It is due to environmental events such as famines, earthquakes, floods, fires, disease, and droughts or human activities such as genocide and human population planning.
  • The frequency of certain alleles in a population change because the organisms that carry them are eliminated.
  • The others increase in number because they are the only alleles left.

Concept:

• Fruits are the mature fertilized ovary, where the fruit wall is formed from the ovary wall and seeds from ovules.
• A fruit consists of 2 parts:
  • Seed - It develops from the ovule.
  • Pericarp - It develops from the ovary wall and may differentiate into epicarp, mesocarp and endocarp layers.
• Fruits can be classified into 3 major types:
  • Simple - These develop from the ovary of a solitary pistil in a single flower. Example- Pea.
  • Aggregate - A group of separate fruits develop from carpels of one flower. Example- Magnolia.
  • Composite - They develop from complete inflorescence. Example- Banyan.

Important Points

• Silique is a dry, dehiscent type of simple fruit.
• It develops from the bicarpellary, syncarpous, superior ovary of a flower.
• Placentation is parietal type.
• Initially the ovary is unilocular, but later becomes bilocular due to a false septum called the replum.
• On maturity the pericarp ruptures in two valves starting from base to apex.
• This leaves the seeds attached to the replum.
• The fruit has more length than breadth.
• It is commonly found in the plants of Brassicaceae family like Brassica nigra.

Other Related Points

• Cucurbitaceae - Fruit type is pepo and is usually indehiscent.
• Malvaceae - Fruit type is capsule or schizocarp.
• Leguminosae - Fruit is usually legume, sometimes lomentum.

• CAM plants are the plants which carry out Crassulacean Acid Metabolism (CAM) for CO₂ fixation.
• It is so-called because it was first found in the Crassulaceae family plants.
• CAM pathway is a special adaptation for conserving water in xeric plants (that are found in dry conditions).
• In this process, the stomata open only at night and remain closed during the day.
• At night, the CO₂ is converted into malic acid which is stored in the vacuole.
• During daytime as the atmospheric CO₂ is absent, the malic acid is transported out of the vacuole and converted to pyruvate and CO₂.
• This CO₂ then takes part in the Calvin-Benson cycle that takes place in the chloroplast.

Explanation:

• CAM plants are often found in desert regions.
• The atmospheric temperatures are usually very high during daytime in desert regions.
• The closed stomata prevents unnecessary water loss through transpiration and thus conserves water in the plant system.
• The Calvin-Benson cycle is the light-independent reaction of photosynthesis and thus can be carried out at night too.

Hence, the correct answer is option (4).

The correct answer is carbohydrates.

Concept:

• Respiratory quotient (RQ) is the ratio of the volume of carbon dioxide (CO₂) evolved to the volume of oxygen (O₂) consumed in respiration.
• It is also referred to as the respiratory ratio.

RQ = Volume of CO₂ evolved / Volume of O₂ consumed

• The Respiratory quotient tends to vary with the respiratory substrate used during respiration.
• This phenomenon occurs during aerobic respiration.

Explanation:

• When Carbohydrates are used as substrate and are completely oxidized, the RQ is always 1.

• This is because the amount of CO₂ evolved is always equal to O₂ consumed.

RQ = 1

Thus, the respiratory quotient is equal to one in carbohydrates.

Other Related PointsRespiratory quotient of Fats:

• The respiratory quotient is less than one in fats.
• If the respiratory substrate is fat, then Respiratory quotient of the respiring cells will be less than 1, because the volume of CO₂ evolved is quite less in comparison to the volume of O₂ being consumed.
• RQ < 1

Respiratory quotient of Proteins:

• If the respiratory substrate is protein then the RQ is variable.
• It varies from 0.5 to 0.9 depending upon the oxygen content of the substrate.

Respiratory quotient of organic acids:

• When the respiratory substrate is an organic acid (for example malic acid) its RQ is greater than 1.
• RQ > 1

Explanation

• Acquired Immunodeficiency Syndrome or AIDS is a syndrome caused by the HIV virus.
• Like any other virus, the HIV virus is made up of nucleic acid and protein.
• Protein covers the nucleic acid and inside a mammalian body, it can act as an antigen.
• Detection of antigens in a body stimulates the immune system, which produces antibodies against it.
• The antigen-antibody reaction is very specific.
• This specific reaction can be used to identify a particular antigen by finding the antibody which reacts with it.
• The reaction of antigen and antibody is detected in ELISA (Enzyme-linked immunosorbent assay).

Process -

• The antibody is linked with an enzyme that can change the color of a substrate.
• A positive reaction between antigen and antibody can lead to a change in color which can be detected.
• The protein of the HIV virus and the specific antibody against it, are used in ELISA to detect the virus.
• If the antibody against the HIV virus reacts with the antigen present in the blood of an infected person, then ELISA will change color and the result will be positive.

​ELISA test is widely used in the detection of HIV virus in the blood of an infected person.