11 NCERT BIOLOGY SUBJECTIVE QUESTIONS

Q1. Name the following receptors: Receptors present on the membranes of cells Receptors present inside the target cell Solution Receptors present on the membranes of cells - Membrane-bound receptors Receptors present inside the target cell - Intracellular receptors Q2. In summer, the urine is more concentrated and thick. Why? Solution Vasopressin is responsible for the reabsorption of water and electrolytes by the distal tubules, and it reduces the loss of water through urine. In summer, the secretion of vasopressin increases which helps the body to conserve more water. Hence, the urine is more concentrated and thick in summer. Q3. Name the hormone which stimulates the secretion of pancreatic enzymes and bile juice. Solution Cholecystokinin (CCK) Q4. Categorise the following hormones according to their chemical nature: Cortisol, epinephrine, triiodothyronine, gonadotropin-releasing hormone, FSH Solution Cortiso

Q1. Name the two parts of the human body which are connected to each other through the Eustachian tube.   Solution The cavities of the middle ear and the pharynx are connected to each other through the Eustachian tube.   Q2. What is corpora quadrigemina? Solution Corpora quadrigemina is the collection of four round lobes which represent the dorsal portion of the midbrain. Q3. Name the gap which exists between pre-synaptic and post-synaptic neurons. Solution Synaptic cleft Q4. Name the pigment present in the photopigments. Solution Opsin Q5. Draw a well-labelled diagram to explain the transmission of the nerve impulse at a synapse. Solution Transmission of nerve impulse at synapse:   Q6. Eyes are the most important sense organs in animals without which it would have been difficult to experience the beauty of life. Name the photoreceptor cells and their pigments present in the retina. Name the compounds pr

Q1. Name the monomer of myosin filament.   Solution Meromyosin   Q2. Represent diagrammatically the sliding filament theory.   Solution Sliding filament theory:         Q3. Name the hormone responsible for osteoporosis. Solution Oestrogen Q4. Why are skeletal muscles called striated muscles? Solution The skeletal muscles have a stripe-like appearance when observed under the microscope. Hence, they are called striated muscles. Q5. Name the bone present at the base of the buccal cavity. Solution Hyoid bone is present at the base of the buccal cavity. Q6. How many bones are present in the front part of the skull which protects the facial region? Solution 14 Q7. Represent diagrammatically the anatomy of a sarcomere. Solution Anatomy of a Sarcomere:   Q8. State the significance of the occipital condyles.   Solution The occipital condyles help the skull to articulate with the superior region of the vertebral co

Q1. Name the disorder in which glucose is present in excess quantities in urine. Solution Glycosuria Q2. Name the branch of the renal artery which enters the glomerulus. Solution Afferent arteriole Q3. Name the excretory organs found in the following organisms: Earthworm Liver fluke Prawns Cockroach Solution Animal Excretory Organs Earthworm Nephridia Liver fluke Flame cells Prawns Green/antennal glands Cockroach Malpighian tubules   Q4. What activates the release of vasopressin from the neurohypophysis?   Solution Excessive loss of body fluid activates the release of vasopressin from the neurohypophysis.   Q5. Name the three layers through which blood is filtered during glomerular filtration.   Solution Layers through which blood filters during glomerular filtration are     Endothelium of glomerular blood vessels   Epithelium of Bowman’s capsule   Basement membrane present betwe

Q1. Name the valve present between the right atrium and the right ventricle. State the significance of the presence of the valve. Solution The tricuspid valve is present between the right atrium and the right ventricle. The presence of valves between these chambers prevents the backflow of blood during the ventricular systole. Q2. Name the type of circulation which provides oxygen to body cells. Solution Systemic circulation Q3. What is bundle of His? Solution Bundle of His constitutes the Purkinje fibres and the left and right branches which have originated from the AV bundle. Q4. What is meant by Angina pectoris? Solution Angina pectoris occurs when arteries constrict and are unable to carry extra blood to the heart at the time of stress. Q5. Name the cell from which thrombocytes originate. State the function of thrombocytes.    Solution Thrombocytes originate from the megakaryocytes. Thrombocytes are involved in blood coagulati

Q1. Name the muscles which increase the volume of the thoracic chamber.   Solution External intercostal muscles   Q2. Represent diagrammatically the exchange of gases at the alveolar level and the tissue level.   Solution     Q3. Describe the process of expiration. Solution When the diaphragm and intercostal muscles are relaxed, the thoracic chamber comes to its normal volume. This reduces the pulmonary volume. This results in an increase in the intra-pulmonary pressure in the lungs than the atmospheric pressure causing the expulsion of air from the lungs. Q4. Name the following: Volume of air which remains in the lungs after normal expiration Total volume of air a person can inspire after normal expiration Solution Volume of air which remains in the lungs after normal expiration - Inspiratory capacity (IC) Total volume of air a person can inspire after normal expiration - Functional residual c