All Free Biology MCQs with Answers

2411. The MRI report of a person unveils the degeneration of intervertebral discs in the lumbar region and protrusion of the spongy nucleus pulposus. The reportindicates that the person is suffering from

• A. Sciatica
• B. Spondylosis
• C. Slipped disc
• D. Disc tumour

Explanation: The MRI report indicates 'degeneration of intervertebral discs in the lumbar region and protrusion of the spongy nucleus pulposus.' These findings are consistent with 'spondylosis,' which is a general term for degenerative changes in the spine, particularly related to the intervertebral discs and vertebrae. Although a 'slipped disc' or herniated disc involves the protrusion of the nucleus pulposus, it is part of the broader category of degenerative spine conditions. Sciatica describes symptoms rather than a specific condition and a disc tumor is not mentioned in the report, making these options incorrect.

2412. Skeletal disease which cause immobility and fusion of vertebral joints is called

• A. Disc slip
• B. Sciatica
• C. Arthritis
• D. Spondylosis

Explanation: Spondylosis, also known as spinal osteoarthritis, is a degenerative disorder that affects the spine, particularly the intervertebral discs and the facet joints. It can lead to the formation of bone spurs and the narrowing of the spinal canal. In advanced cases, it can cause immobility and fusion of vertebral joints, especially in the cervical (neck) or lumbar (lower back) regions.

2413. Study the four statements (A-D) given below and select the two correct ones out of them. A. Definition of biological species was given by Ernst Mayr. B. Photoperiod does not affect reproduction in plants. C. Binomial nomenclature system was given by R.H. Whittaker. D. In unicellular organisms, reproduction is synonymous with growth.

• A. B and C
• B. C and D
• C. A and D
• D. A and B

Explanation: Photoperiod affects flowering and reproduction in plants. Binomial nomenclature system was given by Carolus Linnaeus.

2414. Nomenclature is governed by certain universal rules. Which one of the following is contrary to the rules of nomenclature?

• A. The names are written in Latin and are italicised
• B. When written by hand the names are to be underlined
• C. Biological names can be written in any language
• D. The first word in a biological name represents the genus name and the second is a specific epithet

Explanation: Biological names are derived either from the Latin language or are Latinised. This is because Latin language is a dead language and therefore it will not change in form or spelling with the passage of time.

2415. Which one of the following is not a correct statement?

• A. A museum has a collection of photographs of plants and animals.
• B. Key is a taxonomic aid for identification of specimens.
• C. Herbarium houses are dried, pressed , and preserved plant specimens.
• D. Botanical gardens have collection of living plants for reference.

Explanation: Museums have collections of preserved plant and animal specimens for study and reference. Specimens are preserved in containers or jars in preservative solutions. Plant and animal specimens may also be preserved as dry specimens. Insects are preserved in insect boxes after collecting, killing, and pinning. Larger animals like birds and mammals are usually stuffed and preserved. Museums often have collections of skeletons of animals too.

2416. The common characteristic between tomatoes and potatoes will be maximum at the level of their:

• A. Family
• B. Order
• C. Division
• D. Genus

Explanation: Potato (Solanum tuberosum) and tomato (Lycopersicum esculentum) both belong to the family Solanaceae, which is commonly called the "potato family". Many plants belonging to this family are sources of vegetables, fruits, etc.

2417. Which one of the following organisms is scientifically correctly named, correctly printed according to the International Rules of Nomenclature, and correctly described?

• A. Musca domestica - a common house reptile
• B. Plasmodium falciparum - a protozoan pathogen causing the most serious type of malaria
• C. felis tigris - the Indian tiger, well protected in Gir forests
• D. E.coli - full name Entamoeba coli, a commonly occurring bacterium in the human intestine

Explanation: Plasmodium falciparum is a protozoan parasite, one of the species of Plasmodium that causes malaria in humans. Being digenetic, its life cycle is complete in two hosts-man and mosquito. Its sexual cycle is completed in the female Anopheles mosquito and infective individuals called sporozoites are formed, Which are transmitted to humans with the bite of infected female Anopheles. The asexual cycle is passed in man in two phases. Malaria caused by P. falciparum (also known as aestivoautumnal, malignant tertian, or pernicious malaria) is the most dangerous form of malaria, with the highest rate of complication and mortality. In this case, the fever cycle is of 48 hours and is often fatal to the patient as it affects the brain. The scientific name of the common house lizard is Hemidactylus whereas Musca domestica is the scientific name of the common housefly. The scientific name of the Indian tiger is Panthera tigris. The full name of E. coli is Escherichia coli.

2418. Which one of the following animals is correctly matched with its particular taxonomic category?

• A. Tiger Tigris, species
• B. Cuttlefish mollusca, class
• C. Humans primata, family
• D. Housefly Musca, order

Explanation: The binomial nomenclature system of naming organisms using a two-part Latinized (or scientific) name was devised by the Swedish botanist Linnaeus (Carl Linne); it is also known as the Linnaean system. The first part is the generic name, the second is the specific name. The zoological name of the tiger is Panthera tigris. So, Tigris is the species name of Tiger.

2419. One of the most important functions of botanical gardens is that:

• A. They provide a beautiful area for recreation
• B. One can observe tropical plants there
• C. They allow ex-situ conservation of germ plasm
• D. They provide the natural habitat for wild life.

Explanation: Ex-situ conservation means "offsite conservation". It is the process of protecting endangered species of plants and animals by removing them from an unsafe or threatened habitat and placing it or part of it under the care of humans. Botanical gardens serve as ex-situ conservation of germplasm of different plants, to maintain rare and endemic plant species, and also to provide recreation and knowledge about plants to the common man.

2420. Species are considered as:

• A. Real basic units of classification
• B. The highest units of classification
• C. Artificial concept of human mind which cannot be defined in absolute terms
• D. Real units of classification devised by taxonomists

Explanation: Species are a natural population or group of natural populations of individuals that are genetically distinct and reproductively isolated with similar essential morphological traits. Species is also a genetically closed system because its members do not interbreed with members of other species. Species are the lowest or basic taxonomic category, e.g., mango (Mangifera indica), potato (Solanum tuberosum), lion (Panthera leo). Hereindica, tuberosum, and Leo are species of genera Mangifera, Solanum, and Pantera respectively. All other taxonomic categories are defined and described about species. For example, a genus is a group of species, and a subspecies or a variety is a part of a species. New species originate from already existing species. Species is considered a basic unit of taxonomy since in the greater majority of cases we do not have intraspecific names.