31. Which of the following is a structure of the heart wall?
[A] Epicardium
[B] Endocardium
[C] Myocardium
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
The structure of the heart wall is made up of 3 layers – epicardium, myocardium, and endocardium.
32. The type of placenta found in humans is called __.
[A] Discoidal
[B] Cotyledonary
[C] Zonary
[D] Diffuse
Show Answer
Correct Answer: A [Discoidal]
Notes:
Placenta found in humans is called discoidal. It is a placenta in which the chorionic villi are arranged in a circular plate.
33. Which is the best example of incomplete dominance?
[A] Wavy hair
[B] Sickle cell anemia
[C] Tay Sachs disease
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Wavy hair, Sickle cell anemia, and Tay Sachs disease are the best example of incomplete dominance.
34. In most species, mitochondrial DNA is passed down from which of the following?
[A] DNA
[B] Mother and Father
[C] Father
[D] Mother
Show Answer
Correct Answer: D [Mother]
Notes:
In most of the species, mitochondrial DNA is passed down from Mother.
35. A rare way that a trait or disorder can be passed down through families is called which of the following?
[A] Sex-linked recessive
[B] Sex-linked dominant
[C] Autosomal dominant
[D] None of these
Show Answer
Correct Answer: B [Sex-linked dominant]
Notes:
A rare way that a trait or disorder can be passed down through families is called Sex-linked dominant. An abnormal gene on the X chromosome can cause sex-linked dominant disease.
36. What is the function of a polymerase chain reaction?
[A] catalyze the joining (ligation) of two large molecules
[B] amplify pieces of DNA
[C] Both 1 and 2
[D] Neither 1 nor 2
Show Answer
Correct Answer: B [amplify pieces of DNA]
Notes:
A polymerase chain reaction is a chemical reaction used by molecular biologists to amplify fragments of DNA.
37. The first transgenic crop was __
[A] Potato
[B] Brinjal
[C] Cotton
[D] Tobacco
Show Answer
Correct Answer: D [Tobacco]
Notes:
The first transgenic crop was Tobacco (a virus-resistance plant), which was developed in the year 1983.
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. An eardrum is absent in ____:
[A] Snakes
[B] Toads
[C] Turtles
[D] Tuatara
Show Answer
Correct Answer: A [Snakes]
Notes:
The ear has three main parts: the outer, middle and inner ear. The outer ear consists of the pinna and the auditory canal. The middle ear is filled with air and contains three tiny bones called ossicles – the anvil, hammer and stirrup. The inner ear contains the semicircular canals and the cochlea. Eardrum is the membrane of middle ear. Snakes have fully developed inner ear structures but no eardrum.
40. A molecule in plants comparable to haemoglobin in animals is ____:
[A] Carotene
[B] Chlorophyll
[C] Cellulose
[D] Cytochrome
Show Answer
Correct Answer: B [Chlorophyll]
Notes:
Haemoglobin is the iron-containing oxygen transporting metalloprotein in the red blood cells of all vertebrates. Similarly, Cytochromes are, in general, membrane-bound haemo-proteins containing heme groups and are primarily responsible for the generation of ATP via electron transport.
