Ch 1The Living World
5-Mark Questions
Define ecosystem.
An ecosystem is fundamentally defined as a community comprising living organisms, known as biotic components, such as plants, animals, and microorganisms, interacting with their non-living physical environment, referred to as abiotic components, which include elements like minerals, climate, soil, sunlight, and water. These components are intricately linked through various interrelationships, where they exchange energy and nutrients. For instance, plants utilize sunlight, water, and minerals for photosynthesis, providing food for herbivores, which in turn become food for carnivores. …
What is the need for classification?
Classification of living organisms is essential for several fundamental reasons. First, it allows us to identify and differentiate closely related species that may appear similar in morphology or behavior, making it possible to distinguish between them based on specific characteristics. Second, classification helps us understand the variation that exists among different species, revealing the diversity of life forms and their unique adaptations to various environments. …
2-Mark Questions
What are the unique characteristic features of living organisms?
Cellular organization Nutrition Respiration Metabolism Movement Reproduction Excretion Homeostasis
The mating between different species produces sterile offsprings.
The mating between different species typically results in sterile offspring because the maternal and paternal chromosomes contributed by the two distinct species are not identical. During meiosis, which is the process of gamete formation, homologous chromosomes need to pair up precisely. However, in hybrid offspring from interspecies mating, the chromosome sets from each parent species are often different in number, structure, or gene sequence. This dissimilarity prevents the proper pairing of homologous chromosomes during prophase I of meiosis. …
Why are molecular tools used now to study taxonomy?
Molecular tools are increasingly utilized in taxonomy due to their high accuracy and authenticity in revealing evolutionary relationships and genetic differences among organisms. These tools primarily involve the analysis of nucleic acids (DNA and RNA) and proteins. By comparing specific gene sequences, such as ribosomal RNA or mitochondrial DNA, scientists can precisely determine the genetic relatedness between species, even when morphological features are very similar or divergent. …
1-Mark Questions (MCQ)
A living organism is differentiated from a non-living structure based on a. Reproduction b. Growth c. Metabolism d. All the above
d. All the above
Ch 2Kingdom Animalia
5-Mark Questions
List the characteristic features that distinguish cartilaginous fishes from living jawless fishes.
Cartilaginous fishes (Chondrichthyes) and living jawless fishes (Cyclostomata) exhibit several distinct characteristic features. Cyclostomes, which include lampreys and hagfishes, are often ectoparasites on other fishes or scavengers, whereas chondrichthyes, such as sharks and rays, are typically free-living predators. The body of cyclostomes is slender and eel-like, lacking scales, while chondrichthyes have tough skin covered with minute, placoid scales. …
List three features that characterize bony fishes.
These fishes have a bony endoskeleton. The skin is covered by ganoid, cycloid or ctenoid scales. Gills are covered by an operculum. They are ammonotelic. They have mesonephric kidneys. External fertilization is seen.
2-Mark Questions
Why flatworms are called acoelomates?
Flatworms are classified as acoelomates because they lack a true coelom, which is a fluid-filled body cavity completely lined by mesoderm. In organisms with a true coelom, this cavity provides space for organs and acts as a hydrostatic skeleton. However, in flatworms, belonging to the phylum Platyhelminthes, the space between their outer body wall and the internal organs is entirely filled with a loose, spongy connective tissue called parenchyma. This makes their body solid, without any internal fluid-filled cavity. …
What are flame cells?
Flame cells are specialized excretory and osmoregulatory cells found predominantly in flatworms, belonging to the phylum Platyhelminthes. These unique cells are characterized by a tuft of cilia that beat rhythmically, resembling a flickering flame, hence their name. They are typically found at the blind ends of a network of tubules throughout the flatworm's body. The beating cilia create a current that drives metabolic wastes and excess water from the interstitial fluid into these tubules, which then open to the exterior through excretory pores. …
In which phyla is the larva trochophore found?
The trochophore larva is a distinctive larval stage primarily found in marine invertebrates belonging to the phyla Annelida and Mollusca. This free-swimming, microscopic larva is typically pear-shaped or top-shaped and is characterized by several bands of cilia. A prominent band of cilia, known as the prototroch, encircles the body anterior to the mouth, enabling locomotion and creating feeding currents. …
1-Mark Questions (MCQ)
The symmetry exhibited in cnidarians is a. Radial b. Bilateral c. Pentamerous radial d. Asymmetrical
a. Radial
Ch 3Tissue Level of Organisation
5-Mark Questions
Some epithelia are pseudostratified. What does this mean?
Pseudostratified epithelia are a type of simple columnar epithelium that appears to be stratified or multilayered, but in reality, it is a single layer of cells. This deceptive appearance arises because the cells are columnar but vary in height, and their nuclei are positioned at different levels within the cells. Not all cells reach the apical surface, but all cells are in contact with the basement membrane. …
Differentiate white adipose tissue from brown adipose tissue
White adipose tissue and brown adipose tissue are two distinct types of fat tissue with different structures and functions. White adipose tissue, which is much more abundant in adults, consists of cells with a single, large lipid droplet that pushes the nucleus and cytoplasm to the periphery, giving them a signet-ring appearance. These cells have fewer mitochondria and are primarily specialized for long-term energy storage in the form of triglycerides. …
2-Mark Questions
Match and find the correct answers I. Ciliated epithelium – a. Outer skin II. Ciliated epithelium – b. Heart III. Squamous epithelium – c. Gall bladder IV. Compound epithelium – d. Ureter a. I – c, II – b, III – d, IV – a b. I – b, II – c, III – d, IV – a c. I – a, II – b, III – c, IV – d d. I – d, II – c, III – b, IV – a
d. I – d, II – c, III – b, IV – a. The correct matching is: Ciliated epithelium is found in the ureter (I – d), where it helps move urine; Ciliated epithelium is also found lining the heart chambers (II – c); Squamous epithelium forms the lining of the gall bladder (III – b), allowing for storage and concentration of bile; and Compound epithelium is present in the outer skin (IV – a), providing protection against mechanical and chemical stresses.
Define organ system?
An organ system is a higher level of organization in multicellular organisms where two or more organs work together in a coordinated manner to perform a common, more complex physical and chemical function essential for the survival of the organism. These organs interact and cooperate to achieve a specific physiological goal. For example, the digestive system, composed of organs like the stomach, small intestine, and liver, works together to process food, absorb nutrients, and eliminate waste. …
What is epithelial tissue? What are its types?
Epithelial tissue is a sheet of cells that covers the body surface or lines the body cavities and organs, serving as a protective and functional barrier. Epithelial tissue is classified into two main types based on the number of cell layers. Simple epithelium consists of a single layer of cells and is found in areas where absorption, secretion, or filtration occurs, such as the lining of the small intestine and blood vessels. …
1-Mark Questions (MCQ)
What are the types of epithelium a. Simple squamous epithelium b. Simple cuboidal epithelium c. Simple columnar epithelium d. Stratified epithelium
a. Simple squamous epithelium
Ch 4Organ and Organ Systems in Animals
5-Mark Questions
Classify earthworms based on their ecological strategies.
Earthworms are classified as epigeics, anecics and endogeics based on their ecological strategies. Epigeics are the surface dwellers e.g., Perionyx excavaus and Eudrilus eugeniae. Anecics are found in the upper layers of the soil e.g., Lampiro mauritii, Lumbricus terrestris. Endogeics are found in deeper layers of the soil e.g., Octochaetona thursoni.
Explain the internal structure of the earthworm.
The internal structure of the earthworm reveals a segmented body plan adapted for its burrowing lifestyle. The body wall is remarkably moist, thin, soft, skinny, and elastic, providing both protection and flexibility. It is composed of several distinct layers: the outermost cuticle, which is a non-cellular protective layer; the epidermis, which lies beneath the cuticle and consists of various cell types including supporting cells for structural integrity, gland cells for mucus secretion to keep the body moist, basal cells for regeneration, and sensory cells for detecting stimuli. …
2-Mark Questions
The location and numbers of malpighian tubules in Periplaneta. a. At the junction of midgut and hindgut, about 150. b. At the junction of foregut and midgut, about 150. c. Surrounding gizzard, eight. d. At the junction of colon and rectum, eight.
a. At the junction of midgut and hindgut, about 150. Malpighian tubules are the excretory and osmoregulatory organs in insects like Periplaneta americana, the common cockroach. They are numerous, typically numbering around 100 to 150, and are found as fine, yellow, filamentous structures attached to the alimentary canal precisely at the junction where the midgut transitions into the hindgut. These tubules absorb solutes, water, and wastes from the hemolymph and empty them into the alimentary canal for excretion.
Find out the correct statement a. In male cockroach, the reproductive sac lie anteriorily. b. In female cockroaches chitinous plates gonapophyses are present around the female genital aperture. c. In male cockroach the sternum of 10th segment have pair of anal cerci. d. In the 12th segment anal styles are seen.
b. In female cockroaches chitinous plates gonapophyses are present around the female genital aperture. This statement is correct. Gonapophyses are specialized chitinous structures that form the ovipositor in female cockroaches, surrounding and protecting the female genital aperture. The other statements are incorrect: in male cockroaches, the reproductive sac lies posteriorly, not anteriorly; in male cockroaches, the sternum of the 9th segment, not the 10th segment, bears a pair of anal cerci; and anal styles are found in the 9th segment, not the 12th segment.
Choose the wrong statement among the following: a. In earthworm, a pair of male genital pore is present. b. Setae help in the locomotion of earthworms. c. Muscular layer in the body wall of an earthworm is made up of circular muscles and longitudinal muscles d. Typhlosole is part of the intestine of earthworms.
d. Typhlosole is part of the intestine of earthworm. This statement is incorrect. While the typhlosole is indeed a part of the intestine in earthworms, the question asks to choose the wrong statement among the given options. The typhlosole is a prominent, internal fold of the dorsal wall of the intestine, running along most of its length. Its primary function is to increase the surface area for absorption of digested food, thus making it a crucial component of the earthworm's digestive system. …
1-Mark Questions (MCQ)
Which of the following are the sense organs of Cockroach? a. Antennae, compound eyes, maxillary palps, anal cerci b. Antennae, compound eye, maxillary palps, and tegmina c. Antennae, ommatidia, maxillary palps, sternum and anal style. d. Antennae, eyes, maxillary palps, and tarsus of walking legs and coxa
a. Antennae, compound eyes, maxillary palps, anal cerci. These are the primary sense organs of a cockroach, enabling it to perceive its environment. The antennae are crucial for touch and smell, compound eyes provide a wide field of vision, maxillary palps assist in tasting and manipulating food, and anal cerci detect vibrations and air currents, helping the cockroach sense danger or movement around it.
Ch 5Digestion and Absorption
5-Mark Questions
What are the uses of food?
Food serves multiple essential functions in the human body. The primary use of food is to provide energy in the form of calories that fuel all metabolic activities and physical work. Beyond energy provision, food supplies organic substances including proteins, carbohydrates, lipids, vitamins, and minerals that are necessary for growth and development, particularly during childhood and adolescence. Food also provides the raw materials required for the replacement of worn-out and damaged tissues throughout life, enabling tissue repair and maintenance. …
What are the special features that help in absorbing digested food?
There is an increase in the small intestine surface area. The villi are present in the inner walls of the intestine. The villi is the absorbtive unit The microvilli present in the villi increase the absorptive surface.
2-Mark Questions
What is chyme? a. The process of conversion of fat into small droplets. b. The process of conversion of micelles substances of glycerol into fatty droplet. c. The process of preparation of incompletely digested acidic food through gastric juice. d. The process of preparation of completely digested liquid food in midgut.
The correct answer is d. The process of preparation of completely digested liquid food in midgut. Chyme is the semi-liquid, partially digested food mass that is formed in the stomach through the mechanical and chemical action of gastric juices. It represents an intermediate stage of digestion where proteins have been partially broken down and fats have begun to be emulsified. The term chyme specifically refers to the acidic, homogeneous mixture that moves from the stomach into the small intestine, particularly the duodenum, where further digestion and absorption occur. …
Which is a false statement? a) Stomach divided into three region b) Cardiac, fundic, pyloric regions c) Pyloric region found between duodenum and jejunum d) Cardiac region has a sphincter
The correct answer is c) Pyloric region found between duodenum and jejunum. This statement is false because the pyloric region is not located between the duodenum and jejunum. The pyloric region is the terminal portion of the stomach that connects to the duodenum through the pyloric sphincter. The duodenum is the first part of the small intestine, and the jejunum is the second part of the small intestine. Therefore, the pyloric region is part of the stomach, not situated between parts of the small intestine. …
Find the correct statement a) Serosa – The outer layer formed of connective tissue b) Serosa – Connective tissue, epithelial tissue c) Serosa – Connective tissue, striated cells d) Serosa – Connective tissue, thin squanmous epithelium
d) Serosa – Connective tissue, thin squamous epithelium. The serosa is the outermost layer of the alimentary canal that consists of two main tissue components. The connective tissue provides structural support and contains blood vessels and nerves, while the thin squamous epithelium forms the outer lining that reduces friction and allows smooth movement of the organs. This combination of tissues makes the serosa an important protective and functional layer of the digestive tract.
1-Mark Questions (MCQ)
Which of the following hormones stimulate the production of pancreatic juice and bicarbonate? a. Angiotensin and epinephrine b. Gastrin ¿md insulin c. Cholecystokinin and secretin d. Insulin and glucagon
c. Cholecystokinin and secretin
Ch 6Respiration
5-Mark Questions
Resistance in the airways is typically low why? Give two reasons.
Airway resistance is typically low due to two main reasons. First, the diameter of most airways in the respiratory system is relatively large, which allows air to flow through with minimal resistance according to the principle that resistance is inversely proportional to the fourth power of the radius. Second, although the smaller airways have narrower individual diameters, they are arranged in parallel to one another, which means their combined cross-sectional area becomes very large. This parallel arrangement significantly reduces the total resistance to airflow. …
How the body makes long-term adjustments when living in high altitude?
When a person travels from sea level to elevations where the atmospheric pressure and partial pressure of O 2 lowered there is a poor binding of O 2 with haemoglobin leads to acute mountain sickness. When the person lives there for a long time the kidney synthesizes the erythropoietin which stimulates the bone marrow to produce more RBCs
2-Mark Questions
Match: 1) Residual volume i) 6000 ml 2) Expiratory reserve volume ii) 2500 – 3000 ml 3) Inspiratory reserve volume iii) 1000 -1100 ml 4) Total lung capacity iv) 1100 -1200 ml 1) i – iv; 2 – i; 3 – ii; 4 – iii b) i – i; 2 – ii; 3 – iii; 4 – iv c) i – iii; 2 – i; 3 – iv; 4 – ii d) i – iv; 2 – iii; 3 – ii; 4 – i
d) i – iv; 2 – iii; 3 – ii; 4 – i. The correct matching is: Residual volume corresponds to 1100-1200 ml, which is the volume of air remaining in the lungs after maximum expiration. Expiratory reserve volume corresponds to 1000-1100 ml, which is the maximum volume of air that can be exhaled after normal expiration. Inspiratory reserve volume corresponds to 2500-3000 ml, which is the maximum volume of air that can be inhaled after normal inspiration. Total lung capacity corresponds to 6000 ml, which is the sum of all lung volumes and represents the maximum volume of air the lungs can hold.
1) Atmospheric air i) Partial pressure of O 2 -104 2) Alveoli ii) Partial pressure of O 2 – 40 3) Tissues iii) Partial pressure of O 2 – 95 4) Oxygenated iv) Partial pressure of O 2 – blood 159 a) i – i; 2 – ii; 3 – iii; 4 – iv b) i – ii; 2 – iii; 3 – i; 4 – iv c) i – iv; 2 – iii; 3 – ii; 4 – i d) i – iv; 2 – i; 3 – ii; 4 – iii
The correct answer is d) i – iv; 2 – i; 3 – ii; 4 – iii. This matching correctly pairs atmospheric air with a partial pressure of O₂ of 159 mmHg, alveoli with a partial pressure of O₂ of 104 mmHg, tissues with a partial pressure of O₂ of 40 mmHg, and oxygenated blood with a partial pressure of O₂ of 95 mmHg. These partial pressure gradients are crucial for the movement of oxygen from the atmosphere through the respiratory system into the blood and finally to the tissues, where oxygen is utilized for cellular respiration.
Make the correct pairs. Column I Column II PIC i) maximum volume of air breathe in after forced QEC ii) Volume of air present after expiration in lungs RVC iii) Volume of air inhaled after expiration SFRC iv) Volume of air exhaled after inspiration a) P – i, Q – ii, R – iii, S – iv b) P – ii, Q – iii R – iv, S – i c) P – ii, Q – iii, R – i, S – iv d) P – iii, Q – iv, R – i, S – ii
d) P – iii, Q – iv, R – i, S – ii. The correct matching is: PIC (Inspiratory Capacity) corresponds to the maximum volume of air that can be breathed in after forced expiration. QEC (Expiratory Capacity) corresponds to the volume of air that can be exhaled after maximum inspiration. RVC (Residual Volume Capacity) corresponds to the volume of air that remains in the lungs after maximum expiration. SFRC (Functional Residual Capacity) corresponds to the volume of air present in the lungs after normal expiration.
1-Mark Questions (MCQ)
Breathing is controlled by a) cerebrum b) medulla oblongata c) cerebellum d) pons
b) medulla oblongata
Ch 7Body Fluids and Circulation
5-Mark Questions
Select the correct biological term. Cardiac muscle, atria, tricuspid systole, auricles, arteries, diastole, ventricles, bicuspid valve, pulmonary artery, cardiac cycle, semilunar valve, veins, pulmonary vein, capillaries, vena cava, aorta.
a. The main artery’ of the blood. Dorsal aorta b. Valves between the left atrium and ventricle. Bicuspid valve c. Technical name for relaxation of the heart. Diastole d. Another name for atria. Auricle e. The main vein. Vena cava f. Vessels which carry blood away from the heart. Aorta g.Two names for the upper chambers of the heart. Auricle h. Thick-walled chambers of the heart. Ventricle I. Carries blood from the heart to the lungs. Pulmonary artery j. Takes about 0.8 sec to complete. Cardiac cycle k. Valves situated at the point where blood flows out of the heart. Semilunar valve l. …
Distinguish between arteries and veins.
Arteries Veins 1. They carry blood away from the heart They carry blood from the parts of the body towards the heart. 2. They lie deep inside the body. They lie on the surface beneath the skin. 3. The walls are thick and non-collapsible They have thinner walls. 4. There are no valves. They have valves. 5. Except for the pulmonary artery all the arteries carry oxygenated blood. Except for the pulmonary vein, all the veins carry deoxygenated blood. 6. Blood pressure is high in the arteries Blood pressure is low in the veins. 7. …
2-Mark Questions
Name and Label the given diagrams to show A, B, C, D, E, F, and G.
This question requires labeling a diagram of the circulatory system or heart structure. Without the specific diagram provided, a complete answer cannot be given. However, typical labels for such diagrams might include chambers of the heart such as right atrium, left atrium, right ventricle, and left ventricle, as well as major blood vessels such as superior vena cava, inferior vena cava, pulmonary artery, pulmonary vein, and aorta. The student should refer to the specific diagram in their textbook and label each part according to the anatomical structures shown.
Name the blood cell secreted by megakaryocytes? a. Red blood cells b. White blood cells c. Platelets d. None of the above a. I – d, II – c, III – b, IV – a b. I – a, II – d, III – b, IV – c c. I – a, II – d, III – b, IV – c d. I – d, II – c, III – a, IV – b
c. I – a, II – d, III – b, IV – c. Megakaryocytes are bone marrow cells that produce platelets through fragmentation of their cytoplasm. Platelets are essential for blood clotting and hemostasis. The correct answer identifies the proper matching of blood cell types with their origins and functions.
Why is the velocity of blood flow the lowest in the capillaries? a. The systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventricle. b. Capillaries are far from the heart, and blood flow slows as distance from the heart increases. c. The total surface area of the capillaries is larger than the total surface area of the arterioles. d. The capillary walls are not thin enough to allow oxygen to exchange with the cells. e. The diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate.
c. The total surface area of the capillaries is larger than the total surface area of the arterioles. Blood velocity decreases in capillaries because they form an extensive branching network with a combined cross-sectional area much greater than that of arterioles or arteries. Although individual capillaries are narrow, their vast number creates a larger total surface area. This increased surface area causes blood to slow down, allowing sufficient time for exchange of gases, nutrients, and waste products between blood and tissue cells. …
1-Mark Questions (MCQ)
What is the function of lymph? a. Transport of O 2 into brain b. Transport of CO 2 into lungs c. Bring interstitial fluid in blood d. Bring RBC and WBC in lymph node
c. Bring interstitial fluid in blood
Ch 8Excretion
5-Mark Questions
Name the three filtration barriers that solutes must come across as they move from plasma to the lumen of Bowman’s capsule. What components of the blood are usually excluded by these layers.
The three filtration barriers that solutes must cross as they move from the plasma in the glomerulus to the lumen of Bowman's capsule are the glomerular capillary endothelium, the basal lamina or basement membrane, and the epithelium of Bowman's capsule. The glomerular capillary endothelium is the innermost layer consisting of endothelial cells with fenestrations or pores that allow small molecules to pass through. The basal lamina is a non-cellular layer of proteins and carbohydrates that acts as a selective filter. …
What forces promote glomerular filtration? What forces oppose them? What is meant by net filtration pressure?
Glomerulus hydrostatic pressure Glomerulus pressure Opposing pressure: Colloidal osmotic pressure, Capsular hydrostatic pressure Net filtration pressure = Glomerular hydrostatic pressure – (Colloidal osmotic pressure + capsular hydrostatic pressure.
2-Mark Questions
Arrange the following structures in the order that a drop of water entering the nephron would encounter them. a) Afferent arteriole b) Bowman’s Capsule c) Collecting duct d) Distal tubule e) Glomerulus f) Loop of Henle g) Proximal tubule h) Renal Pelvis
The correct sequence in which a drop of water entering the nephron would encounter the structures is: afferent arteriole, glomerulus, Bowman's capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct, and renal pelvis. This sequence follows the path of filtrate formation and movement through the nephron, starting from the entry of blood through the afferent arteriole into the glomerulus where ultrafiltration occurs, then through Bowman's capsule where the filtrate is collected, followed by selective reabsorption in the proximal convoluted tubule, concentrat …
In which segment of the nephron most of the re-absorption of substances takes place?
The proximal convoluted tubule (PCT) is the segment of the nephron where most of the reabsorption of useful substances takes place. In this region, selective reabsorption occurs through both active transport and passive transport mechanisms. Glucose, amino acids, ions, and water are reabsorbed from the filtrate back into the blood through the capillary network surrounding the proximal convoluted tubule. The cells lining the proximal convoluted tubule are specialized with numerous mitochondria to provide energy for active transport and microvilli to increase the surface area for reabsorption.
What solute is normally present in the body to estimate GFR in humans?
The glomerulus filtrate consists of water glucose amino acids creatinine protein salts and urea. These solutes decide the glomerular filtration rate.
1-Mark Questions (MCQ)
If Henle’s loop were absent from mammalian nephron, which one of the following is to be expected? a) There will be no urine formation b) There will be hardly any change in the quality and quantity of urine formed. c) The urine will be more concentrated d) The urine will be more dilute
d) The urine will be more dilute
Ch 9Locomotion and Movement
5-Mark Questions
Differentiate the oxidative fibre from the glycolytic fibre.
Oxidative fibres and glycolytic fibres differ in several important characteristics. Oxidative fibres, also called red muscle fibres, contain numerous mitochondria that enable them to generate energy through aerobic respiration. They depend heavily on blood flow to deliver oxygen and nutrients, and they contain high levels of myoglobin, which gives them their characteristic red colour and allows them to store oxygen. These fibres are suited for sustained, endurance activities. …
What is meant by foramen magnum?
It is a large opening found at the posterior base of the skull. Through this opening, the medulla oblongata of the brain descends down as the spinal cord.
2-Mark Questions
Where is a ciliary movement taking place?
The correct answer is d) Reproductive tract. Ciliary movement takes place in multiple locations within the body, including the respiratory tract where cilia help move mucus and trapped particles, and the reproductive tract where ciliary action aids in the movement of gametes. In the female reproductive tract, cilia lining the fallopian tubes help propel the ovum toward the uterus. In the male reproductive tract, cilia assist in the movement of sperm. …
Match and Find the Correct Pair 1. Sarcoplasm – a) Respiratory pigment 2. Myoglobin – b) Glucose giver 3. Glycosome – c) Unit of skeletal muscle 4. Sarcomere – d) cytoplasm
a) I- d, II – a, III – b,IV- c
Find the correct and wrong statement and arrange the following statement. 1. The contraction of muscle fibres depends on the actin and myosin protein. 2. The thick muscle fibres depend on Myosin. 3. Each meromyosin molecule will have a globular head with a long arm. 4. The head of the meromyosin bears an actin-binding site and an ATP binding site.
The statements are evaluated as follows: The contraction of muscle fibres indeed depends on the interaction of actin and myosin proteins. Myosin forms the thick muscle fibres. Each meromyosin molecule consists of a globular head attached to a long arm. Crucially, the head of the meromyosin possesses both an actin-binding site and an ATP binding site, which are essential for muscle contraction. Therefore, the correct sequence of true/false is True, True, False, True, as the description of meromyosin's structure is partially incorrect regarding the arm.
1-Mark Questions (MCQ)
Which of the following is not related to skeletal muscle?
(c) It is an involuntary muscle
Ch 10Neural Control and Coordination
5-Mark Questions
Why is the blind spot called so?
Slightly below the posterior pole of the eye, the optic nerve and the retinal blood vessels enter the eye. This region is devoid of both rods and cones, the photoreceptor cells responsible for vision. Since there are no photoreceptors present in this area, light falling on this region cannot be detected or processed, resulting in a gap in the visual field. Hence, this region is called the blind spot. …
Sam’s optometrist tells him that his intraocular pressure is high. What is this condition called and which fluid does it involve?
The increase in intraocular pressure leads to the disease called Glaucoma. Any block in the canal of Schlemm increases the intraocular pressure of aqueous humor and leads to ‘Glaucoma’ where the optic nerve and the retina are compressed due to pressure.
2-Mark Questions
Examine the diagram of the two cell types A and B given below and select the correct option. a) Cell – A is the rod cell found evenly all over the retina b) Cell – A is the cone cell more concentrated in the fovea centralis c) Cell – B is concerned with colour vision in bright light d) Cell – A is sensitive to bright light intensities
Based on the diagram, cell B is concerned with colour vision in bright light. Cell B represents a cone cell, which is responsible for photopic vision, meaning vision in well-lit conditions and the perception of color. Cone cells are concentrated in the fovea centralis, the area of sharpest vision in the retina. Cell A, likely a rod cell, is more sensitive to dim light and is responsible for scotopic vision, or black and white vision, and is distributed more evenly across the retina, except at the very center.
All of the following are associated with the myeline sheath except a) Faster conduction of nerve impulses b) Nodes of Ranvier forming gaps along the axon c) Increased energy output for nerve impulse conduction d) Saltatory conduction of action potential
The correct answer is c) Increased energy output for nerve impulse conduction. The myelin sheath is associated with faster conduction of nerve impulses, the formation of nodes of Ranvier which create gaps along the axon, and saltatory conduction of action potentials where the impulse jumps from one node to the next. However, myelinated nerve fibers actually require less energy for impulse conduction compared to unmyelinated fibers because the action potential only needs to be regenerated at the nodes of Ranvier rather than along the entire length of the axon, making conduction more energy-effi …
Cornea transplant in humans is almost never rejected State the reason.
Cornea transplant in humans is almost never rejected because the cornea does not have blood vessels. Since there are no blood vessels in the cornea, immune cells such as lymphocytes and antibodies cannot easily reach the transplanted corneal tissue to mount an immune response against it. The absence of vascularization means that the cornea is immunologically privileged, making it one of the few tissues that can be successfully transplanted between individuals without the need for immunosuppressive therapy or perfect tissue matching.
1-Mark Questions (MCQ)
Which structure in the ear converts pressure waves to action potentials? a) Tympanic membrane b) Organ of Corti c) Oval window d) Semicircular canal
b) Organ of Corti
Ch 11Chemical Coordination and Integration
5-Mark Questions
Posterior pituitary secretion is controlled by a) hypothalamic hypophyseal portal blood vessel b) neuroendocrine gland c) hypophysis d) hypothalamic hypophyseal axis
The correct answer is d) hypothalamic hypophyseal axis. The posterior pituitary, also known as the neurohypophysis, is controlled by the hypothalamic-hypophyseal axis through a neuroendocrine mechanism. Unlike the anterior pituitary, which is controlled by releasing hormones transported through the hypothalamic-hypophyseal portal blood vessels, the posterior pituitary is directly connected to the hypothalamus by nerve fibers called the hypothalamic-hypophyseal tract. …
Write on the origin of the pituitary gland?
The pituitary gland has a dual embryonic origin reflecting its two distinct lobes. The anterior lobe, also called the adenohypophysis, originates from the embryonic invagination of pharyngeal epithelium known as Rathke's pouch. This pouch arises from the roof of the oral cavity and grows upward during embryonic development. The posterior lobe, also called the neurohypophysis or pars nervosa, originates from the base of the brain as a downward outgrowth of the hypothalamus. This neural origin explains why the posterior lobe maintains direct neural connections with the hypothalamus. …
2-Mark Questions
A male child is born to a parent as he grew if FSH and LH are not properly secreted what happens to the male child. a) He grows like a normal male child b) He grows and he shows stunted growth c) Secondary sexual characters are not developed properly d) He grows as a mentally depressed male
The correct answer is c) Secondary sexual characters are not developed properly. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are gonadotropins secreted by the anterior pituitary gland. In males, FSH stimulates spermatogenesis in the seminiferous tubules of the testes, while LH stimulates the production of testosterone by the Leydig cells. Testosterone is essential for the development of secondary sexual characteristics in males, including facial and body hair growth, deepening of voice, development of male reproductive organs, and increased muscle mass. …
Prabhu is working in a MNC Company. He has to do night shift once in every fifteen days. Aftern a few years he is suffering from sleeplessness (in somnia) What may be the cause of his problem. a) It may be becauses of his nature of work b) More work pressure c) The sleepwake cycle is disturbed due to the irregular synthesis of melotonin hormone d) Due to the metabolic disturbances
The correct answer is c) The sleep-wake cycle is disturbed due to the irregular synthesis of melatonin hormone. Melatonin is a hormone produced by the pineal gland that regulates the sleep-wake cycle, also known as the circadian rhythm. This hormone is synthesized in response to darkness and its levels increase during the night, promoting sleep, while decreasing during daylight hours. When Prabhu works night shifts once every fifteen days, his sleep-wake cycle becomes irregular and disrupted. …
Why is insulin tablet not advisable for chronic diabetic Mellitus patients? a) It takes more time to act b) The insulin find it difficult to reach the substrate c) Insulin is easily digested by the digestive enzymes d) The insulin is not an effective one.
Insulin tablets are not advisable for chronic diabetic mellitus patients because oral administration of insulin is ineffective. Insulin is a protein hormone, and like other proteins, it would be digested by the enzymes present in the gastrointestinal tract, such as pepsin and trypsin, into amino acids. Therefore, it would be broken down before it could be absorbed into the bloodstream and reach its target cells to exert its glucose-lowering effect. For this reason, insulin must be administered via injection to bypass the digestive system and enter the circulation directly.
1-Mark Questions (MCQ)
Which of the following is not related to hormones?
(d) They play an important role indigestion
Ch 12Trends in Economic Zoology
5-Mark Questions
Write the advantages of vermicomposting.
Vermicomposting provides excellent organic manure for sustainable agro-practices. Marketing of vermicompost can provide a supplementary income. Vermicompost is rich in essential plant nutrients. It improves soil structure, texture, aeration, and water holding capacity and prevents soil erosion. It is rich in nutrients and an eco-friendly amendment to soil for farming and terrace gardening, It enhances seed germination and ensures good plant growth.
What are the main duties of a worker bee?
Worker bees perform a variety of essential tasks throughout their lifetime, with their duties changing as they age in a process called temporal polyethism. During the first half of her life, lasting approximately three weeks, the worker bee performs indoor duties within the hive. She secretes royal jelly from her hypopharyngeal glands to feed the larvae and the queen, and prepares bee-bread, which is a mixture of pollen and honey, to nourish the developing larvae. …
2-Mark Questions
Name the three castes in a honey bee colony.
Queen bee Drone Worker bee
Name the following * The largest bee in the colony: * The kind of flight which the new virgin queen takes along with the drones out of the hive:
The queen. Nuptial flight.
What happens to the drones after the mating flight?
The drones, which are the male honey bees, die after copulation. During the mating flight, a drone mates with a queen bee, and immediately after successful copulation, the drone dies. This occurs because the reproductive organs of the drone are designed such that they are torn away from his body during mating, causing fatal injury. This ensures that the drone cannot mate again and that his genetic material is passed on only once, maintaining genetic diversity in the colony.
1-Mark Questions (MCQ)
During the process of vermiculture which of the following does not happen?
(d) Synthesis of organic substances
Frequently asked questions
- Define ecosystem.
- An ecosystem is fundamentally defined as a community comprising living organisms, known as biotic components, such as plants, animals, and microorganisms, interacting with their non-living physical environment, referred to as abiotic components, which include elements like minerals, climate, soil, sunlight, and water. These components are intricately linked through various interrelationships, where they exchange energy and nutrients. For instance, plants utilize sunlight, water, and minerals for photosynthesis, providing food for herbivores, which in turn become food for carnivores. …
- What is the need for classification?
- Classification of living organisms is essential for several fundamental reasons. First, it allows us to identify and differentiate closely related species that may appear similar in morphology or behavior, making it possible to distinguish between them based on specific characteristics. Second, classification helps us understand the variation that exists among different species, revealing the diversity of life forms and their unique adaptations to various environments. …
- What are the unique characteristic features of living organisms?
- Cellular organization Nutrition Respiration Metabolism Movement Reproduction Excretion Homeostasis
- The mating between different species produces sterile offsprings.
- The mating between different species typically results in sterile offspring because the maternal and paternal chromosomes contributed by the two distinct species are not identical. During meiosis, which is the process of gamete formation, homologous chromosomes need to pair up precisely. However, in hybrid offspring from interspecies mating, the chromosome sets from each parent species are often different in number, structure, or gene sequence. This dissimilarity prevents the proper pairing of homologous chromosomes during prophase I of meiosis. …
These important questions are selected from the Samacheer Kalvi Class 11 Zoology textbook book-back exercises to help you revise the most useful questions. Mark weightage (5/2/1) follows the usual exam pattern and may vary by exam — always check your latest syllabus and question pattern. Open each chapter for the complete set of questions and answers.