Biology Archives

31. Which one of the following is a disease for which India has not faced

Which one of the following is a disease for which India has not faced epidemic at any point of time in the past?

Cholera

Plague

Leukaemia

Swine flu

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Leukaemia is a type of cancer affecting blood cells and does not occur in epidemic form.

Epidemics refer to a widespread occurrence of an *infectious disease* in a community at a particular time. Cholera and Plague are historical infectious diseases that have caused major epidemics in India. Swine flu (H1N1) is a viral infectious disease that has also caused outbreaks in India.

While cancer rates can vary regionally or over time, it is not an infectious disease and does not spread from person to person in a way that causes epidemics. The term “epidemic” is specific to infectious diseases.

32. In which part of the heart and circulatory system of human body does d

In which part of the heart and circulatory system of human body does deoxygenated blood flow?

Aorta

Pulmonary vein

Left atrium

Vena cava

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Deoxygenated blood from the body flows into the right side of the heart via the Vena Cava.

The circulatory system involves two main loops: the systemic circulation (body) and the pulmonary circulation (lungs). Deoxygenated blood returns from the body via the superior and inferior vena cava to the right atrium, then to the right ventricle, which pumps it to the lungs.

Oxygenated blood returns from the lungs via the pulmonary veins to the left atrium, then to the left ventricle, which pumps it to the body via the aorta. Therefore, the aorta, pulmonary vein (carrying blood *from* lungs), and left atrium all carry oxygenated blood (with the pulmonary artery and vena cava carrying deoxygenated blood as key exceptions to the typical vein/artery oxygenation rule).

33. Which one of the following statements is correct?

Which one of the following statements is correct?

Euplectella and Spongilla belong to different phyla of Animalia.

Sea anemone belongs to phylum Echinodermata.

Holothuria is a member of phylum Mollusca.

Scolopendra (Centipede) is a member of phylum Arthropoda.

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Scolopendra (Centipede) is indeed a member of the phylum Arthropoda.

Arthropoda is the largest phylum in the animal kingdom and includes insects, spiders, crustaceans, and myriapods (like centipedes and millipedes). Centipedes belong to the class Chilopoda within Arthropoda.

Let’s analyze the other options: A) Euplectella and Spongilla are both types of sponges and belong to the phylum Porifera, so they are in the same phylum. B) Sea anemones belong to the phylum Cnidaria (or Coelenterata), not Echinodermata. C) Holothuria (Sea cucumber) belongs to the phylum Echinodermata, not Mollusca.

34. According to the National Trachoma Survey Report (2014 – 17), India is

According to the National Trachoma Survey Report (2014 – 17), India is now free from infective trachoma. Trachoma is a chronic infective disease of

Nose

Heart

Ear

Eye

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UPSC CISF-AC-EXE – 2018

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Trachoma is a chronic infective disease of the eye. The National Trachoma Survey Report (2014–17) declaring India free from infective trachoma refers specifically to this eye disease.

– Trachoma is caused by the bacterium *Chlamydia trachomatis*.
– It affects the eyes and is the world’s leading infectious cause of blindness.
– The infection causes scarring of the inside of the eyelid, which can lead to eyelashes turning inwards (trichiasis) and rubbing against the cornea, eventually causing irreversible blindness.

The declaration of India being free from infective trachoma is a significant public health achievement, a result of long-term efforts under the National Programme for Control of Blindness and Visual Impairment, focusing on the WHO’s SAFE strategy (Surgery, Antibiotics, Facial cleanliness, Environmental improvement).

35. The X-chromosome linked colour blindness affects the ability to detect

The X-chromosome linked colour blindness affects the ability to detect the difference between which of the following lights ?

Green light and red light

Yellow light and blue light

Blue light and violet light

Yellow light and red light

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X-chromosome linked colour blindness is most commonly red-green colour blindness. This condition affects the photoreceptor cells in the eye (cones) that are sensitive to red and green light, making it difficult to distinguish between these colours.

X-linked colour blindness primarily impairs the ability to distinguish between red and green colours.

Colour blindness is often inherited and is much more prevalent in males because the genes responsible for the most common forms are located on the X chromosome. Females have two X chromosomes, so a functional gene on one X chromosome can often compensate for a non-functional one on the other, whereas males only have one X chromosome.

36. Young children with vitamin D deficiency have trouble in absorbing whi

Young children with vitamin D deficiency have trouble in absorbing which of the following minerals ?

Calcium and Phosphorus

Iron and Sodium

Sodium and Potassium

Zinc and Iron

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Young children with vitamin D deficiency have trouble in absorbing Calcium and Phosphorus.

– Vitamin D is essential for the absorption of calcium and phosphorus from the small intestine.
– These minerals are crucial for bone mineralization and overall bone health.
– In children, a deficiency in vitamin D leads to inadequate absorption of calcium and phosphorus, resulting in rickets, a condition characterized by soft and weak bones, bone deformities, and impaired growth.
– Iron is essential for red blood cell formation, and its absorption is primarily influenced by factors like Vitamin C.
– Sodium and Potassium are important electrolytes, and their balance is regulated by the kidneys and other hormones, not directly by Vitamin D absorption.
– Zinc is involved in various metabolic processes, and its absorption is not directly dependent on Vitamin D.

Vitamin D is synthesized in the skin upon exposure to sunlight and can also be obtained from certain foods or supplements. Severe vitamin D deficiency can lead to osteomalacia in adults (softening of bones).

37. In dialysis for kidney failure patients, the dialysing fluid is iso-os

In dialysis for kidney failure patients, the dialysing fluid is iso-osmotic to

Blood

Urine

Water

Body fluid

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In dialysis for kidney failure patients, the dialysing fluid is iso-osmotic to Blood.

– Dialysis is a process that filters waste products and excess fluid from the blood when the kidneys are unable to perform these functions.
– The dialysing fluid, or dialysate, is a sterile solution that is separated from the patient’s blood by a semi-permeable membrane (the dialyser or peritoneum).
– The dialysate is carefully formulated to have an osmotic pressure similar to that of normal blood plasma (making it iso-osmotic to blood) to prevent damage to blood cells and large shifts in fluid balance.
– Waste products like urea and creatinine, which are in high concentration in the patient’s blood, diffuse across the membrane into the dialysate where their concentration is low.
– Excess electrolytes in the blood can also be removed, and necessary electrolytes added to the blood from the dialysate, facilitating balance.
– Water removal (ultrafiltration) is typically achieved by creating a pressure gradient or sometimes by adding glucose to the dialysate to increase its osmotic pressure slightly compared to blood, but the base solution is iso-osmotic.

While the dialysate composition aims to restore the body’s overall fluid and electrolyte balance (related to “Body fluid”), the direct interaction is with the blood flowing through the dialyser. Therefore, its osmotic property is most critically matched to blood plasma to ensure safe and effective filtration and solute exchange without causing harm to blood cells.

38. Binomial nomenclature means

Binomial nomenclature means

Biological names are generally in Latin and written in italics. The first word is the genus and the second word is the species.

Biological names are generally taken from father and mother.

Biological name originates from order and genus.

Biological name originates from phylum and genus.

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Binomial nomenclature means Biological names are generally in Latin and written in italics. The first word is the genus and the second word is the species.

– Binomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages.
– The first part of the name is the genus name, and the second part is the specific epithet (often called the species name).
– The genus name is always capitalized, and the specific epithet is not.
– Both parts are italicized when printed (e.g., Homo sapiens) or underlined when handwritten.
– This system was largely standardized by Carl Linnaeus in the 18th century.
– Options B, C, and D describe incorrect origins or structures for biological names.

Binomial nomenclature provides a unique and internationally recognized name for each species, avoiding confusion caused by common names which can vary regionally or for the same organism. This standardized naming system is fundamental to biological classification (taxonomy).

39. Kingdom Monera includes

Kingdom Monera includes

Euglenoids and Protozoans

Archaebacteria and Eubacteria

Fungi and Phycomycetes

Basidiomycetes and Deuteromycetes

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Kingdom Monera includes Archaebacteria and Eubacteria.

– The Kingdom Monera is a biological kingdom composed of prokaryotic organisms, which are single-celled organisms that lack a membrane-bound nucleus and other membrane-bound organelles.
– This kingdom traditionally included all bacteria. In modern classification systems (like the three-domain system), Monera is split into two domains: Archaea (Archaebacteria) and Bacteria (Eubacteria). However, in the older five-kingdom system (Whittaker’s classification), Monera encompassed both groups.
– Euglenoids and Protozoans belong to the Kingdom Protista (unicellular eukaryotes).
– Fungi, Phycomycetes, Basidiomycetes, and Deuteromycetes belong to the Kingdom Fungi (multicellular or unicellular eukaryotes, heterotrophic).

The classification of life into kingdoms has evolved over time. The five-kingdom system (Monera, Protista, Fungi, Plantae, Animalia) is widely taught but has been partly superseded by the three-domain system (Archaea, Bacteria, Eukarya) based on genetic analysis. Under the three-domain system, Monera as a single kingdom is obsolete, but the components (Archaea and Bacteria) align with the older Archaebacteria and Eubacteria.

40. Which of the following items is/are associated with the mulberry plant

Which of the following items is/are associated with the mulberry plant?
1. Silk
2. Cocoon
3. Pashmina
4. Hemp
Select the correct answer using the code given below :

1 and 2 only

1, 2 and 3 only

1 and 4 only

2 only

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Silk and Cocoon are directly associated with the mulberry plant.

– The mulberry plant (genus Morus) is the primary food source for the silkworm Bombyx mori, which is the most widely used species in commercial sericulture (silk production).
– Silkworms feed on mulberry leaves and then spin cocoons made of silk fibers. The silk yarn is subsequently obtained from these cocoons.
– Pashmina is a fine type of wool obtained from the Cashmere goat, native to high altitudes of the Himalayas. It is not related to the mulberry plant.
– Hemp is a fiber derived from the Cannabis plant and is used for textiles, paper, biofuels, etc. It is not associated with the mulberry plant.

Sericulture is the cultivation of silkworms for the production of silk. Different types of silk exist (like Muga, Eri, Tasar), some of which are produced by silkworms that feed on plants other than mulberry, but mulberry silk is the most common variety.