Biology (Part-IV) (UPSC)

Total Questions: 66

11. Among the following, which one lays eggs and does not produce young ones directly? [2008]

Correct Answer: (a) Echidna
Solution:

• Monotremes are egg-laying mammals, and echidnas, along with the platypus, are the only surviving members of this group.
• Echidnas are found in Australia and New Guinea, and they have several distinctive features and behaviors that make them interesting subjects of study.
• Often described as a curious blend of hedgehog and anteater, echidnas are even more enigmatic and remarkable than commonly thought.
• There are four species of echidnas, and they are native to Australia and New Guinea. They are also known as spiny anteaters. The four species are the short-beaked echidna (found in Australia and New Guinea) and three species of long-beaked echidnas (found in New Guinea).

12. The release of which one of the following into ponds and wells helps in controlling the mosquitoes? [2008]

Correct Answer: (c) Gambusia fish
Solution:

• Gambusia fish is also known as mosquito fish, and is widely used as a biological agent for controlling mosquito larvae.
• It is native to the waters of the south-eastern United States.
• It has been a part of mosquito-control strategies over a century in various parts of the world, including India.
• A single full grown fish eats about 100 to 300 mosquito larvae per day.
• Also it has been part of various malaria control strategies in India since 1928, including the Urban Malaria Scheme.
• The International Union for Conservation of Nature declared Gambusia one of the 100 worst invasive species in the world.

13. Among the following, which one is not an ape? [2008]

Correct Answer: (c) Langur
Solution:Gibbon, Gorilla and Orangutan are apes, but Langur is not an ape, it is monkey.
Langurs are a type of leaf-eating monkey whose multi-chambered stomach allows them to digest the stodgy plant food in between feeding times. The complicated digesting system is the reason for their big belly. Langurs have a high fiber diet, which can range from leaves and unripe fruits to bark and blossom are slowly digested by the langurs unique gut flora digested during their long rest periods. You can tell if their stomach is working when you hear them burp.
Langurs belong to a family of primates known as Cercopithecidae, or Old World monkeys. An extremely large family of primates, the 159 species and 23 genera presently recognized range across Africa, India, East, and South East Asia. The family is subdivided into two subfamilies; the Cercopithecinae, which includes the baboons, macaques, mangabeys, and guenons, and the Colobinae, which includes the leaf-eating monkeys. The subfamily Colobinae is further divided into two tribes, the Colobini, or Colobus monkeys of Africa, and the tribe Presbytini, which includes the langurs of Asia.

14. In the context of genetic disorders, consider the following: A woman suffers from colour blindness while her husband does not suffer from it. They have a son and a daughter. In this context, which one of the following statements is most probably correct? [2009]

Correct Answer: (d) Son suffers from colour blindness while daughter does not suffer from it.
Solution:

From the above graphical presentation we concluded that the son is the colourblind but the daughter is the carrier.
• Colour blindness is a sex-linked recessive disorder due to a defect in either red or green cone of the eye resulting in failure to discriminate between red and green colour.
• The defect is due to mutation in certain genes present in the X chromosome.
• It occurs in about 8 per cent of males and only about 0.4 per cent of females.
• This is because the genes that lead to red-green colour blindness are on the X chromosome.
• Males have only one X chromosome and females have two.

15. In the context of Indian wild life, the flying fox is a: [2009]

Correct Answer: (a) Bat
Solution:Bats are commonly known as fruits bats or flying foxes. In India these are present in North-Eastern parts or in Andaman and Nicobar Islands.

About Indian Flying Fox bat:
• It is a species of flying fox native to the Indian subcontinent.
• It is one of the largest bats in the world.
• The nectar and fruit-eating flying fox (Pteropus giganteus) is generally considered a vermin as they raid orchards.
• It is a keystone species causing seed dispersals of many plants in tropical systems.
• Appearance
• The Indian flying fox is so called due to its unique, fox-like appearance: reddish-brown coat, characteristically long snout as well as large eyes. And indeed, this animal resembles a little fox with wings.
• Distribution: These bats are endemic to South Central Asia, found from Pakistan and China to the Maldive Islands.
• Habits and Lifestyle
• It is highly social creatures, forming large roosts of several hundred animals.
• These bats live in a ‘vertical’, male-dominated hierarchy system, where higher-ranked individuals occupy higher spots of the tree, while lower-ranked individuals remain on lower spots.

16. With reference to the evolution of living organisms, which one of the following sequences is correct? [2009]

Correct Answer: (c) Salamander-Python-Kangaroo
Solution:According to evolution of living organisms Salamander-Python-Kangaroo, because the evolution started from amphibians 350 million years ago, reptiles appeared 300 million years ago and 200 million years ago first small mammals appeared.

Fish with stout and strong fins could move on land and go back to water. This was about 350 mya. These animals called lobefins evolved into the first amphibians that lived on both land and water. These were ancestors of modern day frogs and salamanders.

17. The Panda belongs to the same family as that of : [2009]

Correct Answer: (a) Bear
Solution:

• Pandas are unique bears that are native to China and are easily identifiable by their white face and black eyes and body. There are two sub-species of panda.
Panda–Giant Panda (Ailuropoda)
• The giant panda belongs to the Ursidae family (Bears).
• The giant panda inhabits the six major mountain ranges in Sichuan, Shaanxi and Gansu provinces of China.
• IUCN Status: Vulnerable
Red Panda (Ailurus fulgens)
• The red panda belongs to its own taxonomically unique Family: Ailuridae.
• Nearly 50 percent of the red panda’s habitat is in the Eastern Himalayas, including Nepal, Tibet, India, Bhutan, and Myanmar.
• IUCN Status: Endangered
Convergent evolution: The giant panda and the red panda do however share some of the same characteristics and a common ancestor. This is called “convergent evolution”.

18. The marine animal called Dugong which is vulnerable to extinction is : [2009]

Correct Answer: (d) Mammal
Solution:Dugong is a large marine mammal. Dugong has a fusiform body with no dorsal fin or hind limbs, instead of possessing paddle. Dugong is heavily dependent on seagrass for subsistence. Dugong bear one calf at a time after an approximately 13 month gestation.

19. Widespread resistance of malarial parasite to drugs like chloroquine has prompted attempts to develop a malarial vaccine to combat malaria. Why is it difficult to develop an effective malaria vaccine? [2010]

Correct Answer: (b) Man does not develop immunity to malaria during natural infection
Solution:It is difficult to develop an effective malaria vaccine, because repeated natural infection does not produce detectable resistance to exo-erythrocytic cycle of malaria in man.
• Malaria is a life-threatening febrile illness caused by Plasmodium parasites, transmitted through the bites of infected female Anopheles mosquitoes.
• The disease is not contagious, but can be spread through infected blood or contaminated needles.
• The most dangerous species are Plasmodium falciparum and Plasmodium vivax.
• Symptoms appear 10–15 days after infection and include fever, chills, and headache.
• Severe symptoms can include seizures, difficulty breathing, jaundice, dark urine, and death if untreated.
• Partial immunity can develop in endemic regions, making diagnosis difficult in some patients.
• Prevention includes vector control, use of mosquito nets, repellents (DEET, IR3535, icaridin), long clothing, and chemoprophylaxis for travellers.
• Early diagnosis and treatment using microscopy or rapid diagnostic tests (RDTs) are critical.

20. Consider the following statements: [2010]

1. Hepatitis B is several times more infectious than HIV/AIDS.

2. Hepatitis B can cause liver cancer.

Which of the statements given above is/are correct?

Correct Answer: (c) Both 1 and 2
Solution:Hepatitis-B is a potentially life-threatening liver infection caused by the hepatitis B virus. It can cause chronic liver disease and puts people at high risk of death from cirrhoris of liver and liver cancer.

Hepatitis-B virus is transmitted between people by contact with blood or other body fluid of an contact with the blood or other body fluid.