21. Which of the following statements is true about Unio?
[A] Unio has a one chambered heart
[B] Unio has a two-chambered heart
[C] Unio has a three-chambered heart
[D] None of the above
Show Answer
Correct Answer: C [Unio has a three-chambered heart]
Notes:
Unio is a genus of medium-sized freshwater mussels. It is an aquatic biennial mollusk, the river mussels, in the family Unionidae. Unio has a three-chambered heart.
22. Which one of the following is a cartilaginous fish?
[A] Silver fish
[B] Dog fish
[C] Cray fish
[D] Star fish
Show Answer
Correct Answer: B [Dog fish]
Notes:
Dogfish is a cartilaginous fish. Cartilaginous fishes (Chondrichthyes) represent the oldest surviving jawed vertebrates.
23. Which of the following is a characteristic of fish?
[A] Tail and venous heart
[B] Venous heart and gills
[C] Epidermal scales and tail
[D] Epidermal scales and gills
Show Answer
Correct Answer: B [Venous heart and gills]
Notes:
Venous heart and gills are characteristic of fish. Fishes are aquatic and cold-blooded vertebrates.
24. Hair is found in all mammals except which of the following?
[A] Chiroptera
[B] Rodentia
[C] Cetacea
[D] Primates
Show Answer
Correct Answer: C [Cetacea]
Notes:
Cetaceans are an entirely aquatic order of mammals comprising whales, dolphins, and porpoises. Hair is found in all mammals except Cetacea.
25. Which nerves send messages from all the senses to the brain?
[A] Motor nerves
[B] Sensory nerves
[C] Mixed nerves
[D] None of these
Show Answer
Correct Answer: B [Sensory nerves]
Notes:
Sensory nerves send messages from all the senses to the brain.
26. The adrenal gland is located above which part of the body?
[A] Kidney
[B] Heart
[C] Brain
[D] Lungs
Show Answer
Correct Answer: A [Kidney]
Notes:
The adrenal gland is located above the Kidney. These glands produce more than 150 hormones that control various functions in the body. The most famous is adrenaline, which triggers the flight or fight response.
27. What happens if your adrenal glands are not working properly?
[A] low blood pressure
[B] low blood levels of sugar
[C] high blood levels of potassium
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
If your adrenal glands are not working properly resulting in low blood pressure, low blood sugar levels, and high levels of potassium in the blood.
28. What is the function of Sertoli cells in the male reproductive system?
[A] help in the erection of the penis
[B] secrete male sex hormones
[C] carrier of man’s genes
[D] provide nutrition to germ cells
Show Answer
Correct Answer: D [provide nutrition to germ cells]
Notes:
Providing nutrition to germ cells is the function of Sertoli cells in the male reproductive system.
29. Where is compound manure made?
[A] Rotted vegetable and animal refuse
[B] Farmyard manure and green manure
[C] Farm refuse and household refuse
[D] Organic wastes from which biogas has been extracted
Show Answer
Correct Answer: A [Rotted vegetable and animal refuse]
Notes:
Compound manure is made of Rotted vegetables and animal refuse. A fertilizer that contains two or more nutrients and is also known as a multi-nutrient fertilizer is called Compound manure.
30. Which of the following is an example of a loose association of nitrogen-fixing bacteria?
[A] Rhizobium
[B] Blue-Green algae
[C] Azotobacter
[D] Azospirillum
Show Answer
Correct Answer: D [Azospirillum]
Notes:
Azospirillum is an example of a loose association of nitrogen-fixing bacteria. Azotobacter is an example of Free-Living Nitrogen-Fixing Bacteria. Rhizobium is an example of Symbiotic Nitrogen-Fixing Bacteria. Blue-Green alga is an example of Symbiotic Nitrogen-Fixing Cyanobacteria.
