Structural Organisation in Animals MCQ

B. All functions are carried out by a single cell. In unicellular organisms, a single cell is responsible for all life processes.

B. Tissues. Tissues are groups of similar cells organized to perform a specific function.

C. To coordinate functions of organs. Organ systems consist of multiple organs working together to perform major bodily functions.

C. To increase efficiency and survival. Division of labour allows specialized cells, tissues, and organs to perform specific tasks efficiently, enhancing the organism’s overall survival.

B. Molecules. While organisms are made of molecules, molecules themselves are not considered a level of biological organization in the hierarchy of cells, tissues, organs, and organ systems.

C. Epithelial. Epithelial tissue covers body surfaces, lines body cavities, and forms glands.

B. Connecting and supporting other tissues. Connective tissue provides structural support, binds tissues together, and includes types like bone, cartilage, and blood.

C. Muscular. Muscular tissue is composed of cells that can contract, generating force and producing movement.

B. It transmits electrical impulses. Neural tissue, comprising neurons and glial cells, is specialized for communication through electrical and chemical signals.

C. Connective, muscular, neural, and epithelial. The heart is a complex organ composed of all four basic tissue types working together.

D. Neural. Neural tissue is specialized for conducting electrical signals (nerve impulses) throughout the body.

A. Covering organs and body surfaces. Epithelial tissue forms the outer layer of the skin, lines internal organs, and cavities.

D. Connective. Connective tissue includes bone, cartilage, tendons, ligaments, and blood, all providing support or connection.

B. Muscular. Muscle tissue contracts to cause movement of body parts or substances within the body.

C. Nervous system. The nervous system, including the brain, spinal cord, and nerves, is composed mainly of neural tissue.

C. Digestive system. An organ system is a group of organs (like the stomach, intestines, liver) working together, such as the digestive system.

D. Kidney. The kidneys are the primary organs of the excretory system responsible for filtering waste products from the blood and producing urine.

D. Four. Most complex organs, like the heart or stomach, are composed of combinations of the four basic tissue types: epithelial, connective, muscular, and neural.

B. Kidney. The kidney is part of the excretory system, while the lungs, bronchi, and trachea are components of the respiratory system.

C. It increases with evolution. Generally, as animals evolved, their organ systems became more complex and specialized.

B. Pumping blood. The heart is the central organ of the circulatory system, responsible for pumping blood throughout the body.

C. Respiratory system. The lungs are the primary organs for gas exchange in the respiratory system of air-breathing vertebrates like frogs.

B. Excretory system. The excretory system, including the kidneys, removes metabolic wastes from the body.

B. Liver. The liver plays a crucial role in detoxification, metabolism, and producing bile for digestion.

C. A group of organs working together for a common purpose. An organ system integrates the functions of several organs to perform complex tasks.

B. Amphibia. Frogs are amphibians, characterized by their ability to live both in water (typically as larvae) and on land (as adults).

B. Rana tigrina. Rana tigrina, the Indian bullfrog, is a common species found in India.

B. They are cold-blooded and body temperature varies with the environment. Poikilothermic (cold-blooded) animals cannot regulate their internal body temperature, which fluctuates with the ambient temperature.

D. Camouflage. Frogs use camouflage (also called protective coloration) to blend in with their surroundings and avoid predators.

B. Summer and winter. Frogs undergo aestivation (summer sleep) during hot, dry periods and hibernation (winter sleep) during cold periods.

C. Amphibian. Amphibians are vertebrates adapted to live both in aquatic and terrestrial environments.

C. Summer. Aestivation is a state of dormancy that helps frogs survive hot and dry summer conditions.

C. Camouflage. Camouflage allows frogs to blend with their environment, making them harder for predators to spot.

B. Winter. Hibernation is a state of inactivity and metabolic depression during the cold winter months.

C. Adaptability. Frogs exhibit various adaptations, such as camouflage, hibernation, and aestivation, allowing them to survive in diverse conditions.

B. To assist in breathing and maintain moisture. The mucus keeps the frog’s skin moist, which is essential for cutaneous respiration (breathing through the skin) and prevents dehydration.

A. Tail. Adult frogs lack a tail, although their larval stage (tadpole) possesses one.

C. Five. Frogs typically have five webbed digits on their hind limbs, adapted for swimming and leaping.

C. It protects the eyes while underwater. The nictitating membrane is a transparent third eyelid that covers and protects the eye when the frog is submerged, while still allowing vision.

D. Digging. While forelimbs aid in walking, landing after leaps, and propping the body, they are generally not adapted for digging. Hind limbs are primarily used for leaping and swimming.

B. Olive green with dark spots. The dorsal (back) side of Rana tigrina is typically olive green with irregular dark spots for camouflage.

A. Tympanum. The tympanum is a visible eardrum located behind the eye, which receives sound vibrations.

B. Presence of vocal sacs. Male frogs typically have vocal sacs (used for croaking) and nuptial pads on their forelimbs, which are absent in females.

B. Swimming. The webbed skin between the digits of the hind limbs increases the surface area, providing propulsion for swimming.

C. Tympanum. The tympanum (eardrum) vibrates when struck by sound waves, transmitting these vibrations to the inner ear.

C. Intestine. Food passes from the stomach into the small intestine (duodenum, then ileum) for further digestion and absorption.

C. Gall bladder. The liver produces bile, which aids in fat digestion, and it is stored in the gall bladder before being released into the intestine.

C. Pancreas. The pancreas produces pancreatic juice containing digestive enzymes that break down carbohydrates, proteins, and fats.

C. Intestine. The final stages of digestion and the primary absorption of nutrients occur in the small intestine.

B. Chyme. Food mixed with gastric juices in the stomach forms a semi-liquid mixture called chyme, which then enters the intestine.

B. Intestine. The inner walls of the intestine, particularly the small intestine with its villi and microvilli, are adapted for absorbing digested nutrients.

B. It produces enzymes for digestion. The pancreas secretes digestive enzymes into the small intestine to break down food molecules.

C. It emulsifies fats. Bile breaks large fat globules into smaller droplets (emulsification), increasing the surface area for enzymes to act upon.

B. Skin. Frogs can absorb dissolved oxygen from water directly through their moist, permeable skin (cutaneous respiration).

C. Pulmonary respiration. Respiration using the lungs is termed pulmonary respiration, common when frogs are on land or active.

C. Through skin. During dormancy (aestivation or hibernation), metabolic rate is low, and cutaneous respiration through the skin is often sufficient.

C. Nostrils. Air enters the frog’s respiratory system through the external nares (nostrils).

B. Skin. Frogs absorb water directly through their permeable skin, particularly through a specialized region on their belly called the “pelvic patch.”

A. Nostrils. Air is drawn into the buccal (mouth) cavity through the nostrils before being forced into the lungs.

B. Three. The frog heart has three chambers: two atria (left and right) and one ventricle.

C. Plasma, RBCs, WBCs, and platelets. Frog blood consists of plasma (liquid matrix) and formed elements including red blood cells (RBCs), white blood cells (WBCs), and platelets (thrombocytes).

B. Carrying oxygen. Hemoglobin, located within red blood cells, binds to oxygen in the lungs and skin capillaries and transports it to the body tissues.

C. Lymphatic system. The lymphatic system collects excess tissue fluid (lymph) and returns it to the bloodstream, and it also plays a role in the immune response.

C. Hepatic portal vein. The hepatic portal system involves the hepatic portal vein carrying nutrient-rich blood from the intestine directly to the liver for processing.

B. Left atrium. The left atrium receives oxygenated blood returning from the lungs and skin.

C. Heart. The pericardium is a protective double-layered sac that encloses the heart.

B. Closed. Frogs have a closed circulatory system, meaning blood is contained within vessels (arteries, veins, capillaries) throughout its circulation.

B. Urea. Adult frogs primarily excrete urea, which is less toxic than ammonia and requires less water for excretion. Tadpoles excrete ammonia.

A. Cloaca. The cloaca is a common chamber that receives waste from the digestive and excretory systems, as well as gametes from the reproductive system, before exiting the body.

D. Urinary bladder. Urine produced by the kidneys travels down the ureters to the thin-walled urinary bladder for temporary storage before being expelled via the cloaca.

C. Urinogenital ducts. In male frogs, the ureters carry both urine from the kidneys and sperm from the testes to the cloaca, hence they are called urinogenital ducts.

C. Ureotelic. Organisms that primarily excrete urea as their nitrogenous waste are termed ureotelic. Adult frogs are ureotelic.

C. Kidney. The kidneys are the primary organs responsible for filtering nitrogenous wastes and excess salts and water from the blood to produce urine.

C. 10. Frogs possess 10 pairs of cranial nerves originating from the brain, controlling various sensory and motor functions.

C. Cerebellum. The cerebellum, located in the hindbrain, is primarily responsible for coordinating muscular activity and maintaining balance.

B. Cranium. The brain is enclosed and protected by the bony cranium, which is part of the skull.

C. Autonomic nervous system. The autonomic nervous system regulates involuntary functions such as heart rate, digestion, and glandular secretions.

B. Midbrain. The midbrain in frogs mainly consists of the optic lobes, which are involved in processing visual information.

B. Coordinates reflex actions and transmits signals. The spinal cord serves as a pathway for nerve signals between the brain and the rest of the body and mediates reflex actions.

B. Near the kidneys. The paired, yellowish testes are attached to the upper part of the kidneys by a fold of peritoneum called the mesorchium.

B. Externally. The female releases eggs into the water, and the male releases sperm over them, resulting in external fertilization.

C. 2500-3000. Female frogs lay a large mass of eggs, typically numbering between 2500 and 3000 at once.

B. Vasa efferentia. Sperm travels from the testes through fine tubules called vasa efferentia, which enter the kidneys and connect to the urinogenital duct.

C. Tadpole. Fertilized frog eggs develop into aquatic larvae known as tadpoles, which undergo metamorphosis to become adult frogs.

C. Metamorphosis. Frogs exhibit metamorphosis, a significant transformation from the aquatic larval (tadpole) stage to the terrestrial/semi-aquatic adult stage.

C. Insect control. Frogs are important predators of insects and other invertebrates, helping to control their populations.

B. Food chain and food web. Frogs serve as both predators (eating insects) and prey (eaten by snakes, birds, etc.), playing a crucial role in the flow of energy through food chains and webs.

B. Controlling pests. By consuming large numbers of insects, frogs help control agricultural pests, benefiting crop production.

C. Muscular legs. The hind legs of some larger frog species are considered a delicacy in various cuisines.

C. By serving as both predators and prey. Their position in the food web helps regulate populations of both invertebrates (their prey) and larger predators (which eat them), contributing to ecosystem stability.

B. They are a food source. Frogs are an important part of the diet for many predators, including snakes, birds of prey, mammals, and larger fish.

B. Habitat destruction. The loss and fragmentation of wetland and forest habitats due to human activities is a primary threat to frog populations worldwide.

C. They control insect populations. As significant insectivores, frogs help keep insect numbers in check, which benefits ecosystems and agriculture.

B. Tadpole. Tadpoles are aquatic herbivores or detritivores, playing a role in consuming algae and decaying matter in freshwater ecosystems.

B. As models in studies of ecology and evolution. Frogs are used in research related to developmental biology, physiology, ecology, and environmental monitoring due to their sensitivity to environmental changes.

B. Insects. Frogs are primarily insectivorous, consuming a wide variety of insects, including many considered pests.

B. Water quality. Due to their permeable skin and reliance on aquatic environments for reproduction, frogs are sensitive to pollutants and changes in water quality, making them good bioindicators.

C. Imbalance in food chains. Over-harvesting frogs for food can disrupt local ecosystems by removing a key predator of insects and a food source for other animals.

C. Freshwater. Frogs are integral components of freshwater ecosystems like ponds, marshes, and streams, both as larvae and adults.

B. Climate conditions. Changes in temperature and rainfall patterns associated with climate change significantly impact frog breeding, development, and habitat availability.