31. Which of the following are examples of connective tissue?
[A] blood
[B] bone
[C] tendon
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Blood, bone, tendon, adipose, ligament, and areolar tissues are examples of connective tissue.
32. What is the role of the atrioventricular valves?
[A] form a network between the arteries to veins
[B] supplying oxygenated blood away from the heart to all other parts of the body
[C] prevent blood from flowing back into the atria
[D] All of the above
Show Answer
Correct Answer: C [prevent blood from flowing back into the atria]
Notes:
When the ventricles contract, the atrioventricular valves close to prevent blood from flowing back into the atria.
33. What is the outermost layer of the heart called?
[A] Myocardium
[B] Endocardium
[C] Epicardium
[D] None of these
Show Answer
Correct Answer: C [Epicardium]
Notes:
The epicardium is the outermost layer of the heart. It is actually the visceral layer of the serous pericardium, which adheres to the myocardium of the heart.
34. The male accessory glands generate fluid that nourishes the sperm called __
[A] semen
[B] seminal plasma
[C] spermatogonia
[D] testosterone
Show Answer
Correct Answer: B [seminal plasma]
Notes:
The male accessory glands generate fluid that nourishes the sperm called seminal plasma and is rich in fructose, calcium, and certain enzymes.
35. Which of the following are the causes of red water?
[A] Clostridium hemolyticum
[B] Achromobacter anitratum
[C] Escherichia coli
[D] Salmonella typhimurium
Show Answer
Correct Answer: A [Clostridium hemolyticum]
Notes:
Clostridium hemolytic are the causes of red water disease. Redwater disease in cattle is caused by a protozoan blood parasite in the erythrocytes.
36. The conversion of N2 to ammonia is known as __
[A] Nitrification
[B] Nitrogen fixation
[C] Ammonification
[D] Denitrification
Show Answer
Correct Answer: B [Nitrogen fixation]
Notes:
The conversion of N2 to ammonia is known as Nitrogen fixation.
37. A molecule that contains nitrogen and has the chemical properties of a base is called __
[A] RNA
[B] Nitrogenous base
[C] Bacteria
[D] Plasmid
Show Answer
Correct Answer: B [Nitrogenous base]
Notes:
A molecule that contains nitrogen and has the chemical properties of a base is called a Nitrogenous base. Nucleic acids are composed of a combination of 5 nitrogenous bases:
1. Guanine and adenine are double-ringed purine molecules.
2. Cytosine, thymine, and uracil are single-ringed pyrimidine molecules.
38. Which of the following protein is found in nails?
[A] Keratin
[B] Histone
[C] Actin
[D] Elastin
Show Answer
Correct Answer: A [Keratin]
Notes:
Keratin is a family of fibrous structural proteins that is the key structural component of hair and nails. It is also the key structural material making up the outer layer of human skin. Besides, it provides the necessary strength and toughness for masticatory organs, such as the tongue.
39. The release of which of the following into ponds and wells helps in controlling mosquitoes?
[A] Snail
[B] Crab
[C] Dogfish
[D] Gambusia fish
Show Answer
Correct Answer: D [Gambusia fish]
Notes:
The Gambusia fish, also known as larvivorous stagnant water fish. It feeds on the larvae of mosquitoes. So it helps in controlling their population. It is also called ‘mosquito fish’ and is being used as a biological control measure. Hence, a check on malaria and other vector borne diseases like even dengue.
40. Which of the following microorganisms is used in milk curdling?
[A] Bacillus
[B] Lactobacillus
[C] Leuconostoc
[D] Acetobacter
Show Answer
Correct Answer: B [Lactobacillus]
Notes:
Lactobacillus acidiphilous is used in milk curdling by producing lactic acid and reducing the pH of the milk. These bacteria convert the lactose into lactic acid, which imparts the sour taste to curd. It is a genus of Gram positive facultative anaerobic or microaerophilic rod-shaped bacteria.
