Given below are two statements: Statement I: During Go phase of cell cycle the cell is metabolically inactive. Statement II: The centrosome undergoes duplication during S phase of interphase.
In the light of the above statements, choose the most appropriate answer from the option below:
Select the correct statements
A.Tetrad formation is seen during leptotene.
B.During Anaphase, the centromere split and chromatids separate.
C.Terminalization takes place during Pachytene.
D.Nucleolus, Golgi complex and ER are reformed during Telophase.
E.Crossing over takes place between sister chromatids of homologous.
Choose the correct answer from the option given below:
Which of the following statements are correct?
A.Basophils are most aboundant cell of the total WBCs.
B.Basophils secrete histamine, serotonin and heparin.
C.Basophils are involved in inflammatory response.
D.Basophils have kidney shaped nucleus.
E.Basophil are agranulocyte.
Choose the correct answer from the options given below:
AI-generated explanation. Check against your textbook.
Explanation:
Basophils are granulocytes; they are not the most abundant WBCs (neutrophils are). They release histamine and heparin, and participate in inflammatory and allergic responses. Their nucleus is typically bilobed or irregular, not kidney-shaped. They are not agranulocytes (they have granules). Therefore, statements B and C are correct, while A, D, and E are incorrect. Hence the answer is option 4 (B and C only).
🧠 Did You Know?
Basophils play a role in inflammation and hypersensitivity by releasing histamine, which increases blood flow and permeability of blood vessels.
💡 NCERT Memory Line:
Neutrophils are the most abundant WBCs; basophils are granulocytes that release histamine and heparin and are involved in inflammatory responses; they are not agranulocytes.
Which of the following statements are correct?
A.An excessive loss of body fluid from the body switches off osmoreceptors.
B.ADH facilitates water reabsorption to prevent diuresis.
C.ANF causes vasodilation.
D.ADH causes increase in blood pressure.
E.ADH is responsible for decrease in GFR.
Choose the correct answer from the options given below:
AI-generated explanation. Check against your textbook.
Explanation:
Correct option: B, C and D. B) ADH (vasopressin) promotes water reabsorption in the kidney, thus reducing diuresis. C) ANF (ANP) causes vasodilation. D) ADH can cause vasoconstriction, raising blood pressure. A) Excessive loss of body fluid increases osmolarity and stimulates osmoreceptors; it does not switch them off. E) ADH mainly saves water and does not cause a direct decrease in GFR as a primary effect in NCERT context. Hence E is not correct.
🧠 Did You Know?
NCERT notes that ADH increases water reabsorption in collecting ducts and can influence arteriolar tone to help maintain blood pressure.
💡 NCERT Memory Line:
ADH prevents diuresis by reabsorbing water in the collecting ducts; ANF causes vasodilation and promotes diuresis.
Which of the following statements are correct regarding skeletal muscle?
A.Muscle bundles are held together by collagenous
connective tissue layer called fascicle.
B.Sarcoplasmic reticulum of muscle fibre is a store house of calcium ions.
C.Striated appearance of skeletal muscle fibre is due to distribution pattern of actin and myosin proteins.
D.M line is considered as functional unit of contraction called sarcomere.
Choose the most appropriate answer from the options given below:
AI-generated explanation. Check against your textbook.
Explanation:
Correct answer: B and C only. In skeletal muscle, sarcoplasmic reticulum stores Ca2+ ions (true). The striated appearance is due to the regular arrangement of actin and myosin within sarcomeres (true). Statement A is false because the bundle of muscle fibres is called a fascicle, which is wrapped by perimysium; fascicle itself is not the connective tissue layer. Statement D is false because the sarcomere is the functional unit of contraction; it is defined by Z-lines, not M-line (M-line is the center within a sarcomere).
🧠 Did You Know?
NCERT describes the connective tissue coverings as endomysium around each muscle fibre, perimysium around a fascicle, and epimysium around the whole muscle.
💡 NCERT Memory Line:
Sarcomere is the functional unit of contraction; its boundaries are defined by Z-lines.
Which of the following are NOT under the control of thyroid hormone?
A.Maintenance of water and electrolyte balance.
B.Regulation of basal metabolic rate.
C.Normal rhythm of sleep-wake cycle.
D.Development of immune system.
E.Support the process of R.B.Cs formation.
Choose the correct answer from the options given below:
Which one of the following is the sequence on corresponding coding strand, if the sequence on mRNA formed is as follow
5'-AUCGAUCGAUCGAUCGAUCGAUCGAUCG-3?