Answer is Option (2) for SSC CHSL Biology MCQ

Archaeopteryx, sometimes referred to by its German name Urvogel, is a genus of early bird that is transitional between feathered dinosaurs and modern birds. The earliest known (from fossils) bird is the 150-million-year-old. It shares the following features with the deinonychosaurs jaws with sharp teeth, three fingers with claws, a long bony tail, hyperextensible second toes (“killing claw”), feathers (which also suggest homeothermy), and various skeletal features. In zoology, Archaeopteryx is a genus of dinosaur that is considered a transitional fossil between reptiles and birds.

Answer is Option (3) for SSC CHSL Biology Questions

The components of dietary fiber include cellulose, lignin (only non-carbohydrate component of dietary fiber), pectin, chitan, etc. Such fibers increase fecal bulk and speed up the passage of food through the digestive tract.

Dietary fiber is a type of carbohydrate found in plant foods that the human body cannot digest or absorb, meaning it passes through the digestive system largely intact, providing bulk to stool and aiding in digestion; it is considered a crucial part of a healthy diet and can be found in Fruits, vegetables, grains, beans, peas and lentils all help you reach that daily fiber goal.

Answer is Option (3) for Biology MCQ for SSC CHSL

Tuberculosis is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis typically attacks the lungs, but can also affect other parts of the body such as the kidneys, spine, or brain, may also be affected. So can the lymph glands and other parts of the body. It spreads through the air when people with TB cough, sneeze or spit. Tuberculosis is preventable and curable.

A person needs to inhale only a few germs to become infected. Every year, 10 million people fall ill with tuberculosis (TB). Without proper treatment, up to two thirds of people ill with TB will die. TB can progress to a more serious, life-threatening infection if left untreated.

Answer is Option (3) for SSC CHSL Biology MCQ

The tests employed to detect commonly present abnormal constituents are proteins, glucose, ketone bodies, bile pigments, bile salts and blood. The liver synthesizes a type of protein known as albumin. Urine should not contain albumin, as protein molecules are large and so easily get trapped in the kidney’s filters and finally they are reabsorbed in the blood stream.

Answer is Option (2) for SSC CHSL Biology Questions

All plants need nitrogen to make amino acids, proteins and DNA, but the nitrogen in the atmosphere is not in a form that they can use. It’s a primary nutrient that’s essential for plant growth. Plants use nitrogen by absorbing either nitrate or ammonium through the roots.

Nutrients that plants require in larger amounts are called macronutrients. About half of the essential elements are considered macronutrients: carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.

Answer is Option (2) for SSC CHSL Biology MCQ

Saliva does not increase the number of red blood cells in the body which is a condition of disease called Polycythemia. It results in an increased level of circulating red blood cells in the bloodstream.

Saliva contains water, proteins, enzymes, electrolytes, hormones, sugars, lipids, and other substances.

Proteins 

• Amylase: An enzyme that breaks down carbohydrates
• Proline-rich peptides (PRPs): A large family of proteins that make up nearly 70% of saliva’s total protein
• Host-defense peptides: Part of the immune system that helps the body respond to infection and inflammation
• Mucins: Large proteins that lubricate the mouth

Enzymes 

• Lingual lipase: Breaks down fats
• Protease: An enzyme that digests proteins

Other substances 

• Urea: A compound that can be used to monitor kidney function
• Histatins: Compounds that may help close wounds and rebuild the lining of the mouth
• Ions: Including sodium, potassium, calcium, bicarbonate, thiocyanate, and phosphate
• Organic substances: Including uric acid and lactate
• Immunoglobulins: An important component of saliva
• Hormones: Including cortisol

Answer is Option (3) for Biology MCQ for SSC CHSL

The common is a viral infectious disease of the upper respiratory tract which affects primarily the nose. Over 200 viruses are implicated in the cause of the common cold; the rhinoviruses are the most common.

Answer is Option (4) for SSC CHSL Biology Questions

Plants absorb water from their root hairs on the root via osmosis. It is then transported to other parts of the plant (through the network of xylem vessels) through a combination of capillary action and “transiprational pull”.

Osmosis plays a crucial role in plants by facilitating water absorption from the soil through root hairs, maintaining cell turgor, supporting plant structure and movement, and regulating the transport of nutrients within the plant by creating pressure gradients within the phloem vessels.

Answer is Option (3) for SSC CHSL Biology MCQ

The open circulatory system is common to mollusks and arthropods. Open circulatory systems pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells. Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood. Cockroaches and silverfish have an open circulatory system. They don’t have any blood vessels.

Answer is Option (3) for SSC CHSL Biology Questions

The amoebas do not have nervous system, but they communicate by means of the interaction of the cellular membrane with the outside that surrounds to him. Like answer for example to an injurious stimulus, irritating or nutritional, the intracellular communication produces a reaction of the complete cell, moving away or approaching the respective stimulus.

Answer is Option (1) for Biology MCQ for SSC CHSL

Gout is a medical condition usually characterized by recurrent attacks of acute inflammatory arthritis— a red, tender, hot, swollen joint. It is caused by elevated levels of uric acid in the blood. The uric acid crystallizes, and the crystals deposit in joints, tendons, and surrounding tissues.

Answer is Option (1) for SSC CHSL Biology Questions

Mitochondria are semi-autonomous organelles that likely began as freestanding prokaryotes that invaded eukaryotic cells more than a billion years ago. A symbiotic relationship eventually developed between these prokaryotic cells and their eukaryotic hosts. The former prokaryotes lost the capacity for independent existence but became indispensable to the eukaryotic cells.

Answer is Option (3) for SSC CHSL Biology MCQ

All proteins contain nitrogen. Precisely, they contain about 16 per cent nitrogen. The determination of protein requirement is based on nitrogen balance, which include total nitrogen in food and excreta.

Answer is Option (1) for SSC CHSL Biology MCQ

The kidneys are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and regulation of blood pressure (via maintaining salt and water balance). They serve the body as a natural filter of the blood, and remove wastes which are diverted to the urinary bladder.

Answer is Option (3) for SSC CHSL Biology Question

Infants under four months of age that drink water or eat food contaminated with high levels of nitrates or nitrites are particularly at risk for methemoglobinemia, or blue baby syndrome. This can occur if water containing high levels of nitrates is used to prepare infant formula, and very rarely if infants eat nitrate-rich spinach which has broken down into nitrite during storage.

Answer is Option (4) for SSC CHSL Biology Questions

An exoskeleton is the external skeleton that supports and protects an animal’s body, in contrast to the internal skeleton (endoskeleton) of, for example, a human. Chondrichthyes or cartilaginous fishes are jawed fish with paired fins, paired nares, scales, a heart with its chambers in series, and skeletons made of cartilage rather than bone.

Answer is Option (3) for SSC CHSL Biology Question

Ecology is the scientific study of the relationships that living organisms have with each other and with their natural environment. Ecosystems are composed of dynamically interacting parts including organisms, the communities they make up, and the non-living components of their environment. Ecosystem processes, such as primary production, pedogenesis, nutrient cycling, and various niche construction activities, regulate the flux of energy and matter through an environment.

Answer is Option (4) for Biology MCQ for SSC CHSL

Lysosomes are known by names such as suicidal bags/ atom bomb and House keeper / scavenger of cell. They are called suicide bags or atom bombs because if the single membrane surrounding the digestive enzyme breaks, the enzymes released may also destroy the cell itself.

Answer is Option (2) for SSC CHSL Biology Question

Quinine, as a component of the bark of the cinchona tree, was used to treat malaria from as early as the 1600’s. The bark of trees in this genus is the source of a variety of alkaloids, the most familiar of which is quinine, an antipyretic (anti-fever) agent.

Answer is Option (4) for SSC CHSL Biology MCQ

Hypertension is a chronic medical condition in which the blood pressure in the arteries is elevated. This requires the heart to work harder than normal to circulate blood through the blood vessels.

Answer is Option (1) for SSC CHSL Biology Questions

Muscle fibers or myofibrils are formed of three types of proteins which are:

(a) contractile,

(b) regulatory, and

(c) structural.

Contractile proteins are the force generators of muscle contraction. The two contractile proteins in myofibrils are Actin which is part of thin filament and Myosin, which is part of the thick filament.

Answer is Option (2) for SSC CHSL Biology MCQ

Lead poisoning (also known as plumbism or painter’s colic) is caused by increased levels of the heavy metal lead in the body. Lead interferes with a variety of body processes and is toxic to many organs and tissues including the heart, bones, intestines, kidneys, and reproductive and nervous systems. It interferes with the development of the nervous system.

Answer is Option (3) for SSC CHSL Biology Questions

Pituitary gland, called Master Gland, is the smallest endocrine gland. It controls the general growth of the body and stimulates the primary sex hormones, i.e. ovaries and testes.

Answer is Option (2) for Biology MCQ for SSC CHSL

The deficiency of magnesium leads to yellowish green blotch near the base of the leaf between the midrib and the outer edge. The yellow area enlarges until the only green remaining is at the tip and base of the leaf as an inverted V-shaped area on the midrib.

Answer is Option (4) for SSC CHSL Biology MCQ

Leishmaniasis (Kala azar) is a disease spread by the bite of the female sandfly. This disease is the second-largest parasitic killer in the world (after malaria). The parasite migrates to the internal organs such as liver, spleen (hence ‘visceral’), and bone marrow, and, if left untreated, will almost always result in the death of the host.

Answer is Option (2) for SSC CHSL Biology Questions

Rayon is a manufactured regenerated cellulose fiber. Because it is produced from naturally occurring polymers, it is neither a truly synthetic fiber nor a natural fiber; it is a semi-synthetic or artificial fiber.

Answer is Option (4) for SSC CHSL Biology MCQ

Itai-itai disease was the documented case of mass cadmium poisoning in Toyama Prefecture, Japan, starting around 1912. The cadmium poisoning caused softening of the bones and kidney failure. The disease is named for the severe pains caused in the joints and spine.

Answer is Option (1) for Biology MCQ for SSC CHSL

Cross fertilization occurs in Hydra. The spermatozoa released from the testis of one Hydra swim about in water with their tails and finally come into contact with the ovum of another Hydra. Only one spermatozoon penetrates the ovum and fertilizes it. This results in the formation of a zygote which is diploid.

Answer is Option (2) for SSC CHSL Biology Questions

Blubber is a thick layer of vascularized adipose tissue found under the skin. Lipid-rich, collagen fiberlaced blubber comprises the hypodermis and covers the whole body, except for parts of the appendages, strongly attached to the musculature and skeleton by highly organized, fan-shaped networks of tendons and ligaments. It can comprise up to 50% of the body mass of some marine mammals during some points in their lives.

Answer is Option (1) for SSC CHSL Biology MCQ

The genetic code by which DNA stores the genetic information consists of “codons” of three nucleotides. The functional segments of DNA which code for the transfer of genetic information are called genes. A codon is defined by the initial nucleotide from which translation starts.

Answer is Option (2) for SSC CHSL Biology MCQ

Calciferol (Vitamin D); Tocopherols and tocotrienols (Vitamin E); Phylloquinone, menaquinones (Vitamin K); and Retinol, retinal, and four carotenoids including beta carotene (Vitamin A) are all fat soluble vitamins.

Answer is Option (3) for SSC CHSL Biology Questions

Silk is a natural protein fibre, some forms of which can be woven into textiles. The protein fibre of silk is composed mainly of fibroin and produced by certain insect larvae to form cocoons. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori.

Answer is Option (4) for Biology MCQ for SSC CHSL

Monotremes are mammals that lay eggs instead of giving birth to live young like marsupials and placental mammals. The only surviving examples of monotremes are all indigenous to Australia and New Guinea, although there is evidence that they were once more widespread. Among living mammals they include the platypus and four species of echidnas (or spiny anteaters).

Answer is Option (2) for SSC CHSL Biology Question

Chameleons have specialized cells, chromatophores, which contain pigments in their cytoplasm, in three layers below their transparent outer skin. Dispersion of the pigment granules in the chromatophores sets the intensity of each color. When the pigment is equally distributed in a chromatophore, the whole cell is intensively colored. When the pigment is located only in the centre of the cell, the cell appears mainly transparent.

Answer is Option (2) for SSC CHSL Biology MCQ

A goitre or goiter is a swelling of the thyroid gland which can lead to a swelling of the neck or larynx (voice box). Goitre is a term that refers to an enlargement of the thyroid and can be associated with a thyroid gland that is functioning properly or not. Worldwide, over 90% cases of goitre are caused by iodine deficiency.

Answer is Option (1) for SSC CHSL Biology Questions

Meat, fish and eggs are the richest sources of protein. An ounce of meat or fish has approximately 7 grams of protein. A large egg contains 6 grams protein.

Answer is Option (3) for SSC CHSL Biology Question

Test tube baby is born from in vitro fertilization. In vitro fertilization (IVF) is a process by which an egg is fertilized by sperm outside the body: in vitro. When a woman’s natural cycle is monitored to collect a naturally selected ovum (egg) for fertilization, it is known as natural cycle IVF. The fertilized egg (zygote) is then transferred to the patient’s uterus with the intention of establishing a successful pregnancy.

Answer is Option (3) for SSC CHSL Biology MCQ

A heart attack occurs when blood flow to a part of your heart is blocked for a long enough time that part of the heart muscle is damaged or dies. The medical term for this is myocardial infarction. Most heart attacks are caused by a blood clot that blocks one of the coronary arteries. The coronary arteries bring blood and oxygen to the heart. If the blood flow is blocked, the heart is starved of oxygen and heart cells die.

Answer is Option (1) for Biology MCQ for SSC CHSL

Bacteria are the most abundant organisms which play important role in the decomposition of organic matter. Majority of bacteria involved in decomposition of organic matter are heterotrophs and autotrophs are least in proportion which are not directly involved in organic matter decomposition.

Answer is Option (3) for SSC CHSL Biology Questions

One way of analyzing carrying capacity of the earth is to calculate its net primary productivity (NPP). This is the total amount of solar energy converted into biochemical energy through plant photosynthesis, minus the energy needed by those plants for their own life processes. It represents the total food resource on earth. In the food chain, meat products stay at the top. Even at the current levels where deforestation and other forms of destruction of vegetation has been rampant, plant products can sustain an extended population base.

Answer is Option (2) for SSC CHSL Biology Question

The literal meaning of ‘sanguinivorous’ is someone subsisting on a diet of blood. Mosquitoes belong to this category.

Answer is Option (3) for SSC CHSL Biology MCQ

Nephron is the basic structural and functional unit of the kidney. Its chief function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting the rest as urine.

Answer is Option (1) for SSC CHSL Biology MCQ

A layer of body fat acts as an insulator and traps heat. The subcutis is the deepest layer of skin. The subcutis, consisting of a network of collagen and fat cells, helps conserve the body’s heat and protects the body from injury by acting as a “shock absorber.

Answer is Option (1) for SSC CHSL Biology Question

The average life span of RBC is about 120 days. The old, worn out and dead RBC are destroyed mainly in an organ called spleen.

• RBCs don’t have a nucleus, so they have a limited lifespan.
• As RBCs travel through blood vessels, they use up their energy supply.
• RBCs undergo several physicochemical changes as they age.
• Macrophages in the spleen, liver, and bone marrow remove senescent RBCs from the circulation through phagocytosis.
• Macrophages phagocytose about 5 million erythrocytes every second.
• The lifespan of a neonatal erythrocyte is only 60 to 90 days.
• Preterm infants have an even shorter life span of 35 to 50 days.

Answer is Option (1) for SSC CHSL Biology Questions

The uterus or womb is a major female hormoneresponsive reproductive sex organ of most mammals including humans. It is within the uterus that the fetus develops during gestation, usually developing completely in placental mammals such as humans and partially in marsupials such as kangaroos and opossums.

Answer is Option (1) for Biology MCQ for SSC CHSL

Edible plant stems are one part of plants that are eaten by humans. Most plants are made up of roots, stems, leaves, flowers, buds and produce fruits containing seeds. The edible portion in an onion is swollen leaves with a bit of stem.

Answer is Option (2) for SSC CHSL Biology Question

Some of the benefits of Mushroom cultivation are:

(a) it has been found to coincide with decrease of incidents of breast cancer;

(b) Spent residues such as those obtained after cultivation of edible mushrooms could be a better source of bio- logically pretreated substrates for biogas production; and

(c) Mushrooms can be grown on virtually all types of available wastes; and

(d) agricultural waste recycling can be achieved through controlled cultivation of mushrooms.

Answer is Option (1) for SSC CHSL Biology MCQ

Drones are male honey bees. They develop from eggs that have not been fertilized, and they cannot sting, since the worker bee’s stinger is a modified ovipositor (an egg laying organ).

Answer is Option (3) for SSC CHSL Biology Questions

Keratin is a fibrous protein making up most cells found in our nails and hair and the epidermis layer of our skin. It also makes up fish scales and crustacean shells, bird feathers and beaks, and animal horns and hooves.

Answer is Option (1) for SSC CHSL Biology Question

Hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells. It is responsible for binding oxygen in the lung and transporting the oxygen throughout the body to be used up in aerobic metabolic pathways. The oxygen binding properties of hemoglobin exist because of the interaction between oxygen and the iron atom of the heme groups and hemoglobin’s quaternary structure.

Answer is Option (4) for SSC CHSL Biology MCQ

The chromosomes which determine the sex (maleness or femaleness) of an individual in sexually producing organisms are called sex chromosomes or allosomes or idiosomes. In humans an individual whose cells contain XX chromosomes (homo or isogametic) becomes a female, while one whose cells contains XY chromosomes (heterogametic) becomes a male.

Answer is Option (2) for Biology MCQ for SSC CHSL

Swim bladder is also known as air bladder for fishes. It is a buoyancy organ possessed by most bony fish. The swim bladder is located in the body cavity and is derived from an out-pocketing of the digestive tube. It contains gas (usually oxygen) and functions as a hydrostatic, or ballast, organ, enabling the fish to maintain its depth without floating upward or sinking. It also serves as a resonating chamber to produce or receive sound.

Answer is Option (3) for SSC CHSL Biology MCQ

The pituitary is sometimes referred to as the “master gland” as it controls hormone functions such as our temperature, thyroid activity, growth during childhood, urine production, testosterone production in males and ovulation and estrogen production in females.

Answer is Option (3) for SSC CHSL Biology Question

Cauliflowers are characterized mainly by their heart which consists of an inflorescence composed of numerous undeveloped flowers that gather around a central axis. Cauliflower and broccoli are grown for their large, edible, very young inflorescence.

Answer is Option (4) for SSC CHSL Biology Questions

Haematopoiesisis the formation of blood cellular components. The sites where haematopoiesis occurs change during embryonic development, but in adult mammals, the bone marrow is the major site of hae matopoiesis. Haematopoietic stem cells in the bone marrow reside in a specialised microenvironment known as the hematopoietic stem cell niche, com posed of osteoblasts, mesenchymal cells and sinu soidal vessels.

Answer is Option (1) for SSC CHSL Biology MCQ

Acid rain is caused due to oxides of sulphur and nitrogen mixing with rain water making rain water acidic. When calcium carbonate of white marble reacts with acidic water, it results into its corrosion. This is known as stone cancer. Our heritage monuments, like the Taj Mahal, are threatened by stone cancer.

Answer is Option (1) for Biology MCQ for SSC CHSL

Benzene is an organic chemical compound sometimes known as benzol which is carcinogenic. Substantial quantities of epidemiologic, clinical, and laboratory data link benzene to aplastic anemia, acute leukemia, and bone marrow abnormalities. One of its forms, Ethylbenzene, is used in Paints (Arts and Craft and Interior/Exterior Building).

Answer is Option (2) for SSC CHSL Biology Questions

The number of muscles in the human body varies from about 656 to 850 (sometimes from 639 to around 800). An exact number is difficult to define. The difficulty lies partly in the fact that different sources group the muscles differently and partly in that some muscles, such as palmaris longus, are not always present.

Answer is Option (4) for SSC CHSL Biology Question

A tannin is an astringent, bitter plant polyphenolic compound that binds to and precipitates proteins and various other organic compounds including amino acids and alkaloids. It refers to the use of wood tannins from oak in tanning animal hides into leather; hence the words “tan” and “tanning” for the treatment of leather. Oak bark, mimosa, chestnut and quebracho tree have traditionally been the primary source of tannery tannin, though inorganic tanning agents are also in use today and account for 90% of the world’s leather production.

Answer is Option (3) for SSC CHSL Biology MCQ

The menstrual cycle is the scientific term for the physiological changes that occur in fertile women and other female primates for the purposes of sexual reproduction. It takes approximately 28 days to complete although this does vary from person to person. Length variation between eight and 20 days is considered as moderately irregular cycles. Variation of 21 days or more between a woman’s shortest and longest cycle lengths is considered very irregular.

Answer is Option (3) for SSC CHSL Biology Question

Keratin is a fibrous protein making up most cells found in our nails and hair and the epidermis layer of our skin. It also makes up fish scales and crustacean shells, bird feathers and beaks, and animal horns and hooves.

Answer is Option (3) for SSC CHSL Biology MCQ

Riboflavin, also known as vitamin B2 is an easily absorbed colored micronutrient with a key role in maintaining health in humans and animals. It plays a key role in energy metabolism, and for the metabolism of fats, ketone bodies, carbohydrates, and proteins.

Answer is Option (2) for SSC CHSL Biology Questions

In tetrapod anatomy, the trachea or windpipe, is a tube that connects the pharynx and larynx to the lungs, allowing the passage of air. It is lined with pseudo-stratified ciliated columnar epithelium cells with goblet cells that produce mucus. This mucus lines the cells of the trachea to trap inhaled foreign particles that the cilia then waft upward toward the larynx and then the pharynx where it can be either swallowed into the stomach or expelled as phlegm.

Answer is Option (3) for SSC CHSL Biology Question

Minamata disease is a neurological syndrome caused by severe mercury poisoning. It was first discovered in Minamata city in Kumamoto prefecture, Japan, in 1956.

Answer is Option (3) for Biology MCQ for SSC CHSL

A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.

Answer is Option (4) for SSC CHSL Biology Question*

The color of normal urine is usually light yellow to amber. Generally, the greater the solute volume the deeper the color. The yellow color of urine is due to the presence of a yellow pigment, urochrome. Deviations from normal color can be caused by certain drugs and various vegetables such as carrots, beets, and rhubarb.

Answer is Option (3) for SSC CHSL Biology MCQ

The old, worn out and dead RBC are destroyed mainly in an organ called spleen. Hence, it is commonly called the ‘graveyard of RBC’. Spleen is present in our body above the stomach and under the left side of the ribs. In one second, approximately 2.5 million RBCs are destroyed.

The spleen is responsible for removing old RBCs. The spleen’s cells phagocytose, or engulf, worn RBCs and platelets. In adults, the spleen also acts as a blood bank.

The average lifespan of erythrocytes is 120 days whereas older or dead erythrocytes are removed from the blood by phagocytic cells in the liver and spleen.

Spleen is like a blood filter that removes destroyed and damaged erythrocyte cells. It is the largest organ of the lymphatic system and also maintains the balance of the body fluid. It also fights against disease-causing germs and protects our body from infection.

Answer is Option (2) for SSC CHSL Biology MCQ

Salt plays a primary role in the processes of digestion and absorption. Salt activates an enzyme in the mouth called salivary amylase. Salt also creates hydrochloric acid. Hydrochloric acid is a very important digestive secretion, which lines the stomach walls.

Answer is Option (1) for SSC CHSL Biology Question

Paper is organic in nature as it is made from wood and pulp. So it is bio-degradable and useful in recycling.

Answer is Option (4) for SSC CHSL Biology Questions

Plants that are resistant to crude oil toxicity such as black poplar and willows, as well as miscanthus grass (elephant grass) have been found to be effective in the remediation of oil polluted soil. Bioadsorbents like Moringo oliefera seeds and Parthenium hysterophorus plants. are effective for the removal of industrial pollutants in water.

Answer is Option (2) for Biology MCQ for SSC CHSL

Cyanobacteria, also known as blue algae, are singlecelled and belong to the family of Prokaryotes. That means, they do not have a cell nucleus. The ability of cyanobacteria to perform oxygenic photosynthesis is thought to have converted the early reducing atmosphere into an oxidizing one, which dramatically changed the composition of life forms on Earth by stimulating biodiversity and leading to the nearextinction of oxygen-intolerant organisms.

Answer is Option (3) for SSC CHSL Biology MCQ

Haemoglobin is an iron-containing protein in red blood cells. It contains a haem prosthetic group that has an iron atom at its centre. When the iron is bound to oxygen, the haem group is red in colour (oxyhameoglobin), and when it lacks oxygen (deoxygenated form) it is blue-red.

Answer is Option (1) for SSC CHSL Biology Questions

The word ‘comose’ means ‘hairy’ in Latin. It refers to certain seeds (such as cotton) having a tuft or tufts of hair. The seeds of plants like Calotropis, Gossypium, etc, possess a large number of hairs which enable them to float in air. Such seeds are described as comose.

Answer is Option (1) for Biology MCQ for SSC CHSL

The open circulatory system is a system in which fluid in a cavity called the hemocoel bathes the organs directly with oxygen and nutrients and there is no distinction between blood and interstitial fluid; this combined fluid is called hemolymph or hemolymph. Arthropods and mollusks have an open circulatory system.

Answer is Option (1) for SSC CHSL Biology MCQ

Heparin also known as un-fractionated heparin, a highly sulfated glycosaminoglycan, is widely used as an injectable anticoagulant, and has the highest negative charge density of any known biological molecule.

Answer is Option (4) for SSC CHSL Biology Questions

The lockjaw is a pathological condition of tetanus. Clostridium tetani bacteria are responsible for tetanus. Main symptoms of tetanus : spasms of muscles and convulsions, lockjaw.

Answer is Option (4) for SSC CHSL Biology Question

Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes. It is a complex carbohydrate, (C₆H₁₀O₅ )_n, that is composed of glucose units.

Answer is Option (3) for Biology MCQ for SSC CHSL

The seed includes three primary regions: the embryo, nutritive tissue, and seed coat. Endosperm is a nutritive tissue that sustains the embryo and seedling. The endosperm may be consumed by the embryo, as in many legumes, which use the cotyledons as a food source during germination.

Answer is Option (1) for SSC CHSL Biology MCQ

Yeast is an important source of most B vitamins (except B₁₂) and folate and contains potassium and magnesium. It is used in the preparation of vitamin B complex tablets.

Answer is Option (2) for SSC CHSL Biology Questions

Kala-azar: caused by protozoan parasites; Tuberculosis: infectious disease caused by various strains of myco-bacteria; Influenza: caused by RNA viruses; and Ringworm: fungal infection of the skin.

Answer is Option (3) for Biology MCQ for SSC CHSL

Plants which either obtain readymade organic food prepared by other plants or absorb water and minerals from other plants to prepare their own organic food are called parasitic plants. Cuscuta (Doddar) is a total stem parasite.

Answer is Option (2) for SSC CHSL Biology MCQ

Monocytes are the largest white blood cell. When they leave the blood they’re called macrophages. Macrophages work with lymphocytes as antigen presenting cells.

 Answer is Option (1) for SSC CHSL Biology Question

The pancreas, located in the abdomen close to the stomach, is both an exocrine and an endocrine gland. Similarly, gonads (both ovaries and testes) are examples of organs that have both endocrine and exocrine functions. The endocrine function of the gonads is the production of the sex hormones (estrogens and androgens); while their exocrine function is to produce gametes.

Answer is Option (4) for SSC CHSL Biology Questions

Microcytic anaemia: anemia characterized by small red blood cells, due to deficiency of iron; Pernicious anaemia: body does not make enough red blood cells due to lack of vitamin B₁₂; Goitre: swelling of the neck or larynx resulting from iodine deficiency; and Pellagra: chronic lack of niacin (vitamin B₃).

Answer is Option (2) for SSC CHSL Biology MCQ

Stomata are pores in the surface of the leaf. The pore is surrounded by two guard cells. When these two guard cells take up water, they bend and open up the pore between them.

Answer is Option (3) for Biology MCQ for SSC CHSL

Rinderpest is an acute, highly contagious viral disease of ruminant animals, primarily cattle, that was once common in Africa, the Indian subcontinent, and the Middle East.

Answer is Option (4) for SSC CHSL Biology Question

The 3 R’s of eco-friendly living are: Reduce, Reuse and Recycle. They all help to cut down on the amount of waste we throw away. They conserve natural resources, landfill space and energy.

Answer is Option (1) for SSC CHSL Biology Questions

Phototropism is the growth of organisms in response to light. In plants, phototropism is a response to blue wavelengths of light and is caused by a redistribution of auxin from the illuminated side to the darker side of the shoot, resulting in quicker growth on the darker side and bending of the shoot toward the source of light.

Answer is Option (4) for SSC CHSL Biology MCQ

Lactogenic hormone is gonadotropic hormone which is secreted by the anterior pituitary. In females, it stimulates growth of the mammary glands and lactation after parturition.

Answer is Option (2) for Biology MCQ for SSC CHSL

Lichens can be used as air pollution indicators, especially of the concentration of sulfur dioxide in the atmosphere. Air pollutants dissolved in rainwater, especially sulfur dioxide, can damage lichens, and prevent them from growing. This makes lichens natural indicators of air pollution.

Answer is Option (3) for SSC CHSL Biology Question

The kidneys maintain our body’s water balance by controlling the water concentration of blood plasma. The kidneys also control salt levels and the excretion of urea.

Answer is Option (1) for SSC CHSL Biology Questions

Algae are chlorophyll (green pigment) containing thallophytes. They prepare their own food and are thus autotrophic in their mode of nutrition.

 Answer is Option (4) for SSC CHSL Biology MCQ

Hydroponics is a method of growing plants using mineral nutrient solutions, in water, without soil. Plants are grown with their roots in the mineral nutrient solution only or in an inert medium, such as perlite, gravel, mineral wool, expanded clay pebbles or coconut husk.

Answer is Option (4) for Biology MCQ for SSC CHSL

Animals and non-green plants cannot prepare their own food and depend directly or indirectly on green plants for their nutrition. This mode of nutrition is called heterotrophic nutrition. Fungi are nonchlorophyllos. They should be classified as animals because of their heterotrophic mode of nutrition. But, they are classified under plant kingdom as they have many plant characters.

Answer is Option (4) for SSC CHSL Biology Questions

Hormone secretion from the anterior pituitary gland is regulated by releasing hormones secreted by the hypothalamus. Neuro-endocrine cells in the hypothalamus project axons to the median eminence, at the base of the brain. At this site, these cells can release substances into small blood vessels that travel directly to the anterior pituitary gland.

Answer is Option (1) for SSC CHSL Biology Question

Self-pollination can lead to inbreeding depression, or the reduced health of the species, due to the breeding of related specimens. This is why many flowers that could potentially self-pollinate have a built-in mechanism to avoid it.

Answer is Option (3) for SSC CHSL Biology MCQ

Vitamin B1 : Thiamine; Vitamin B2 : Riboflavin; Vitamin B6 : Pyridoxine; Vitamin B12 : Cyano-cobalamin.

Answer is Option (2) for Biology MCQ for SSC CHSL

When plants and animals die, they become food for decomposers like bacteria, fungi and earthworms. The dead things that are eaten by decomposers are called detritus which means “garbage”.

Answer is Option (1) for SSC CHSL Biology Question

Deciduous means “falling off at maturity” or “tending to fall off”. Deciduous trees or shrubs lose their leaves seasonally. The converse of deciduous is evergreen.

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The laws of heredity were discovered by Gregor Mendel in about 1856-1863. Mendel conducted experiments in plant hybridization, collecting the results of cross-fertilizing hundreds of edible pea plants. The results from Mendel’s experiments confirmed his ideas about heredity: the law of segregation, which has become known as Mendel’s First Law, and the law of independent assortment, also known as Mendel’s Second Law.