Biology GK Questions Quiz-67

Biology GK Questions Quiz-67

Biology Multiple Choice Questions (MCQs) Quiz for State and UPSC Civil Services Examinations. Objective Questions on Biology for competitive examinations.

    1321.A group of genes whose activity is coordinated by a DNA site is called:

    (1) operon 
    (2) cistron
    (3) polysome 
    (4) polypeptide
    Answer:
    1321.(1) The operon is defined as a group of genes whose activity is coordinated by a DNA site. An operon is a functioning unit of genomic DNA containing a cluster of genes under the control of a single promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo trans-splicing to create monocistronic mRNAs that are translated separately.

    1322.Which of the following human genetic disorders is sex-linked ?

    (1) Haemophilia
    (2) Cystic fibrosis
    (3) Albinism
    (4) PKU
    Answer:
    1322.(1) Haemophilia is a group of hereditary genetic disorders that impairs the body’s ability to control blood clotting, which is used to stop bleeding when a blood vessel is broken. It is a sex-linked recessive disorder which is more likely to occur in males than females.

    1323.Which is the largest blood vessel in human body?

    (1) Aorta
    (2) Anatomises
    (3) Tunica Intima
    (4) Atrium
    Answer:
    1323.(1) Aorta is the largest blood vessel in human body. It is the largest of the systemic circulation arteries. Blood enters the aorta from the left ventricle of the heart by way of a one-way valve to prevent backflow. From the aorta, several arterial branches carry oxygenated blood to all tissues in the body.

    1324.Copper is associated with ____ mitochondrial enzymes.

    (1) Cytochrome oxidase
    (2) Succinic dehydrogenase
    (3) Catalase
    (4) Acid phosphatase
    Answer:
    1324.(1) Copper is involved in normalized function of many enzymes, such as cytochrome c oxidase, which is complex IV in mitochondrial electron transport chain, ceruloplasmin, Cu/Zn superoxide dismutase, and in amine oxidases. These enzymes catalyze reactions for oxidative phosphorylation, iron transportation, antioxidant and free radical scavenging and neutralization, and neurotransmitter synthesis, respectively.

    1325.Metals can be ____ at room temperature.

    (1) Liquid only
    (2) Solid only
    (3) Solid or liquid
    (4) Solid, liquid or gas
    Answer:
    1325.(3) All metals except Mercury are solid at room temperature. Mercury is the only metallic element that is liquid at standard conditions for temperature and pressure; the only other element that is liquid under these conditions is bromine.

    1326.Which one of the following is also called as milk sugar?

    (1) Glucose 
    (2) Fructose
    (3) Maltose 
    (4) Lactose
    Answer:
    1326.(4) Lactose is the sugar found in milk. It is a combination of glucose and another small sugar called galactose. It is a form of double sugar. Lactose makes up around 2–8% of milk (by weight).

    1327.The name of the longest muscle in human body is

    (1) Sartorius muscle
    (2) Massete muscle
    (3) Stapedius muscle
    (4) Gluteus Maximus muscle
    Answer:
    1327.(1) The Sartorius muscle is the longest muscle in the human body. It is a long, thin, superficial muscle that runs down the length of the thigh in the anterior compartment. Its upper portion forms the lateral border of the femoral triangle.

    1328.Which of the following range of Air Pollutant Index is considered as hazardous ?

    (1) 301-500 
    (2) 201-300
    (3) 101-200 
    (4) 401-500
    Answer:
    1328.(1) An Air Quality Index(AQI) of 301-500 is considered as hazardous to human health. It denotes the severely polluted state of air. AQI values over 300 trigger health warnings of emergency conditions. The entire population is even more likely to be affected by serious health effects.

    1329.DNA shows hyperchromicity on:

    (1) heating 
    (2) cooling
    (3) crystallizing
    (4) replication
    Answer:
    1329.(1) When a DNA solution is heated enough, the doublestranded DNA unwinds, and the Hydrogen bonds that hold the two strands together weaken and finally break. The process of breaking a double-stranded DNA into single strands is known as DNA denaturation, or DNA melting. The hyperchromicity of DNA occurs when the DNA duplex is denatured.

    1330.Which part of human body is affected by the ALZHEIMER’S disease?

    (1) Heart 
    (2) Kidney
    (3) Immune System
    (4) Brain
    Answer:
    1330.(4) Alzheimer disease is an irreversible, progressive disorder in which brain cells (neurons) deteriorate, resulting in the loss of cognitive functions, primarily memory, judgment and reasoning, movement coordination and pattern recognition. It leads to nerve cell death and tissue loss throughout the brain.

    1331.What do you call the study of fungi?

    (1) Mycology 
    (2) Parasitology
    (3) Bacteriology 
    (4) Ecology
    Answer:
    1331.(1) Mycology is the branch of biology concerned with the study of fungi. It includes the study of fungi’s genetic and biochemical properties, their taxonomy and their use to humans as a source for tinder, medicine, food, and entheogens, as well as their dangers, such as poisoning or infection.

    1332.Which of the following is true for photoperiodic ?

    (1) It occurs only in plants
    (2) It is related to flowering in plants
    (3) It is related to feathers of animals
    (4) It is the reaction of organisms to the length of day or night
    Answer:
    1332.(4) Photoperiodism is the physiological reaction of organisms to the length of day or night. The term “Photoperiodism” was coined to describe a plant’s ability to flower in response to changes in the photoperiod: the relative lengths of day and night. Because flowers produce seeds, flowering is crucially important for the plant to complete its life cycle.

    1333.Motor skills are associated with which part of the brain?

    (1) Frontal lobe
    (2) Parietal Lobe
    (3) Temporal lobe
    (4) Occipital Lobe
    Answer:
    1333.(1) Motor skills are needed to control the movements of the different muscles in the human body. The frontal lobe plays a large role in voluntary movement. It houses the primary motor cortex which regulates activities like walking. The frontal lobes are also involved in problem solving, spontaneity, memory, language, initiation, judgement, impulse control, etc.

    1334.Which enzyme is present in all members of the animal kingdom except Protozoa?

    (1) Insulin
    (2) Pepsin
    (3) Renin 
    (4) Amylase
    Answer:
    1334.(4) Digestion in Protozoa is carried on by several enzymes such as peptidase, proteinase, lipase, etc. For example, Insulin has important role in the glucose uptake of protozoa. However, protozoa lack amylase which is required for the digestion of fats and starch. It is due to the absence of amylase that protozoa such as amoeba cannot digest fats and starch.

    1335.The most serious air pollutant causing health hazard is

    (1) Sulphur dioxide
    (2) Carbon monoxide
    (3) Ozone
    (4) Nitrogen oxide
    Answer:
    1335.(1) Sulphur dioxide (SO2) is considered as the most serious single air pollutant causing health hazard, obstructing breathing. It always leads to airways inflammation, eye irritation, psychic alterations, pulmonary oedema, heart failure and circulatory collapse. It is also responsible for acid rain.

    1336.Which cell organelle is the site of photosynthesis and also contains chlorophyll?

    (1) chloroplasts 
    (2) vacuole
    (3) cytoplasm 
    (4) nucleolus
    Answer:
    1336.(1) Chloroplast, found in plant cells, is the site of photosynthesis in plants to prepare food(glucose) for the plant with the use of energy.It is a green plastid that contains chlorophylls a and b that absorb visible light energy and convert it to usable chemical energy in photosynthesis.

    1337.Highest source of air pollution in the world is

    (1) Automobiles
    (2) Industries
    (3) Household wastes
    (4) Aircraft
    Answer:
    1337.(1) According to the US Environmental Protection Agency (EPA), automobile emissions are the number one source of carbon monoxide, lead, nitrogen oxides, and volatile organic compounds released into the atmosphere that are primarily responsible for air pollution. Industrial processes are the number two cause of lead pollution in the air, following automobile emissions.

    1338.What is contained in Chlorophyll ?

    (1) Sodium 
    (2) Potassium
    (3) Manganese 
    (4) Magnesium
    Answer:
    1338.(4) The basic structure of a chlorophyll molecule is a porphyrin ring, coordinated to a central atom. This is very similar in structure to the heme group found in hemoglobin, except that in heme the central atom is iron, whereas in chlorophyll it is magnesium. This was discovered in 1906, and was the first time that magnesium had been detected in living tissue.

    1339.Why is Carbon Monoxide a pollutant ?

    (1) Reacts with haemoglobin
    (2) Makes nervous system inactive
    (3) It reacts with Oxygen
    (4) It inhibits glycolysis
    Answer:
    1339.(1) Carbon monoxide (CO) is considered a pollutant since it is toxic to hemoglobic animals (including humans) when encountered in concentrations above about 35 ppm. It combines with hemoglobin to produce carboxyhemoglobin, which usurps the space in hemoglobin that normally carries oxygen, but is ineffective for delivering oxygen to bodily tissues. A level of 50% carboxyhemoglobin may result in seizure, coma, and fatality.

    1340.Why is Rann of Kutch of India famous for ?

    (1) Tidal and flats
    (2) Fertile soil
    (3) Dense Vegetation
    (4) All are correct
    Answer:
    1340.(1) The Great Rann of Kutch is a seasonal salt marsh located in the Thar Desert in the Kutch District of Gujarat, India and the Sindh province of Pakistan. It is known for its marshland and mud flats, also known as tidal flats, that are coastal wetlands which form when mud is deposited by tides or rivers.

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