What is a constellation?
- A.A particular pattern of equidistant stars from the earth in the sky
- B.A particular pattern of stars that may not be equidistant from the earth in the sky
- C.A particular pattern of planets of our solar system in the sky
- D.A particular pattern of stars, planets and satellites in the sky due to their position in the space
Correct answer
Explanation
The correct answer is B, a particular pattern of stars that may not be equidistant from the earth in the sky. A constellation is a group of stars that appears to form a shape when seen from the earth, but its stars usually lie at very different distances from us.
The stars of a constellation only look close together because they lie in nearly the same direction in our sky. One star of the group may be a few dozen light-years away while another is hundreds of light-years away. The International Astronomical Union recognises 88 constellations, such as Orion, Ursa Major (Saptarishi) and Cassiopeia, and uses them to divide the sky into regions for naming and locating stars.
Option A is wrong because the stars of a constellation are not at equal distances from the earth. Option C is wrong because planets keep moving against the background of stars and are never part of a fixed pattern. Option D is wrong because a constellation is made only of stars, not planets or satellites.
Exam tip: constellation = apparent star pattern; Ursa Major = Saptarishi, and its pointer stars lead to the Pole Star.
Practice Questions
View allWhich one of the following statements is correct?
- A.Urea is produced in liver.
- B.Urea is produced in blood.
- C.Urea is produced from digestion of starch.
- D.Urea is produced in lung and kidney.
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Liver cells turn the toxic ammonia released from the breakdown of amino acids into urea through the ornithine cycle, also called the urea cycle.
Read the full explanation →Which one of the following is the correct sequence of passage of light in a compound microscope?
- A.Condenser-Objective lens-Eyepiece-Body tube
- B.Objective lens-Condenser-Body tube-Eyepiece
- C.Condenser-Objective lens-Body tube-Eyepiece
- D.Eyepiece-Objective lens-Body tube-Mirror
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Light passes through the condenser to the specimen, is picked up by the objective lens, travels up the body tube and reaches the eye through the eyepiece.
Read the full explanation →Which one of the following statements regarding haemoglobin is correct?
- A.Haemoglobin present in RBC can carry only oxygen but not carbon dioxide.
- B.Haemoglobin of RBC can carry both oxygen and carbon dioxide.
- C.Haemoglobin of RBC can carry only carbon dioxide.
- D.Haemoglobin is only used for blood clotting and not for carrying gases.
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It binds oxygen at its iron-containing haem groups and carries some carbon dioxide on its protein chains. Each haemoglobin molecule has four polypeptide chains and four haem groups, and each haem iron can hold one oxygen molecule, forming oxyhaemoglobin in the lungs.
Read the full explanation →Which one of the following statements regarding histone proteins is correct?
- A.Histones are proteins that are present in mitochondrial membrane.
- B.Histones are proteins that are present in nucleus in association with DNA.
- C.Histones are proteins associated with lipids in the cytosol.
- D.Histones are proteins associated with carbohydrates in the cytosol.
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They are the proteins around which DNA winds to form chromatin in the nucleus of eukaryotic cells. Histones are small basic proteins, rich in the positively charged amino acids lysine and arginine, which attract the negatively charged phosphate groups of DNA.
Read the full explanation →The Hooke's law is valid for
- A.only proportional region of the stress-strain curve
- B.entire stress-strain curve
- C.entire elastic region of the stress-strain curve
- D.elastic as well as plastic region of the stress-strain curve
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Hooke's law says stress is directly proportional to strain, and that holds only up to the proportional limit, where the curve is a straight line.
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