1. In which of the following Cloaca which is the posterior opening that serves as the only such opening for the intestinal, reproductive and urinary tracts is present?
[A] Aves only
[B] Aves & Amphibians
[C] Aves, Amphibians and Reptiles
[D] Pisces, Aves, Amphibians & Reptiles
Show Answer
Correct Answer: C [Aves, Amphibians and Reptiles]
Notes:
Cloaca which is the posterior opening that serves as the only such opening for the intestinal, reproductive and urinary tracts is present in Aves, Amphibians and Reptiles. A cloaca is not present in placental mammals.
2. Biologists have been able to demonstrate the hearing and sound sensory mechanism through the acoustico-lateralis system in which of the following vertebrates ?
[A] amphibians
[B] snakes
[C] fishes
[D] Birds
Show Answer
Correct Answer: C [fishes]
Notes:
Biologists have been able to demonstrate the hearing and sound sensory mechanism through the acoustico-lateralis system in fishes.
3. Consider the following statements:
- Color blindness is more common in men.
- Color blindness is an X-linked recessive trait.
- If both the X chromosomes are defective, a woman may have color blindness.
Which of the above statements are correct?
[A] Only 1
[B] 1, 2 and 3
[C] 2 and 3
[D] Only 1 and 2
Show Answer
Correct Answer: B [1, 2 and 3]
Notes:
Color blindness is more prevalent in men as it is an X-linked recessive disorder. Men, having only one X chromosome, are more susceptible if it is defective. Women, with two X chromosomes, become color blind only if both carry the defective gene. All three statements accurately describe the inheritance and prevalence of color blindness.
4. Which among the following Vitamin is added to the milk in some countries as it is lost during the process of Fat Removal (Skimming)?
[A] Vitamin A
[B] Vitamin B
[C] Vitamin C
[D] Vitamin D
Show Answer
Correct Answer: A [Vitamin A]
Notes:
Vitamin A is added to the milk in some countries as it is lost during the process of Fat Removal called Skimming. Vitamin A is important for good vision, a healthy immune system, and cell growth.
5. Meg-1 is an imprinted gene which finds expression only from maternal chromosomes which regulates the transfer of nutrients from the plant to the seed. This gene has been discovered in :
[A] Maize
[B] cotton
[C] jute
[D] Sugarcane
Show Answer
Correct Answer: A [Maize]
Notes:
Meg-1 gene was developed in Maize. It is an imprinted gene which finds expression only from maternal chromosomes which regulates the transfer of nutrients from the plant to the seed.
6. Gargling with a solution of table salt is known to provide relief for a sore throat because ____ ?
[A] It kills bacteria
[B] It works as analgesic
[C] It dehydrates water from inflammatory tissues by Osmosis
[D] None of the above reasons
Show Answer
Correct Answer: C [ It dehydrates water from inflammatory tissues by Osmosis]
Notes:
Gargling with a solution of table salt is known to provide relief for a sore throat because it dehydrates water from inflammatory tissues by Osmosis. Gargling with salt water helps cure the throat infection.
7. The greatest degree of genetic variability would be expected among organisms that reproduce via__?
[A] Budding
[B] Sporulation
[C] Sexual Recombination
[D] Vegetative Propagation
Show Answer
Correct Answer: C [ Sexual Recombination]
Notes:
Genetic variability is usually due to a mutation during meiosis (sexual reproduction). In the above question, the answer choices (B) and (D) are examples of asexual reproduction. They create identical offspring.
8. Who coined the term “Tissue culture”?
[A] Montrose Thomas Burrows
[B] Jack Kevorkian
[C] Charles Scott Sherrington
[D] Ludvig Hektoen
Show Answer
Correct Answer: A [Montrose Thomas Burrows]
Notes:
Tissue culture is the growth of tissues or cells in an artificial medium separate from the organism. It refers to the culture of animal cells and tissues, with the more specific term plant tissue culture being used for plants. The term “tissue culture” was coined by American pathologist Montrose Thomas Burrows.
9. Which of the following facts is true regarding Colour blindness?
[A] More common among women
[B] Very rare in women
[C] Very rare in men
[D] Found to the same extent in both the sexes
Show Answer
Correct Answer: B [Very rare in women]
Notes:
Color blindness occurs when light-sensitive cells in the retina fail to respond appropriately to variations in wavelengths of light that enable people to see an array of colors. Photoreceptors in the retina are called rods and cones. It is very rare in women.
10. Which of the following clearly defines the meaning of Plankton? (UPSC Prelims 1982)
[A] A kind of fish
[B] A submerged platform in waters
[C] Drifting of organisms in a body of water
[D] A kind of animal living under water
Show Answer
Correct Answer: C [Drifting of organisms in a body of water]
Notes:
Planktons are very small plants and animals that float on the surface of the sea and on which other sea animals feed.
