The colourful part of the Sunflower or Marigold plant is
- A.Flower
- B.Inflorescence
- C.Fruit
- D.Seed
Correct answer
Explanation
The correct answer is B, Inflorescence. What looks like a single flower in a sunflower or marigold is really a head made of many tiny flowers, called florets, packed together.
This kind of inflorescence is called a capitulum or head, typical of the family Asteraceae (Compositae), to which sunflower, marigold, daisy and dahlia belong. The florets sit on a flat, broad base called the receptacle. The bright outer florets that look like petals are ray florets, and the small ones filling the centre are disc florets. Each disc floret of a sunflower can form a fruit, which is why one head yields hundreds of "seeds".
A is wrong because the colourful head is not one flower but a cluster of many florets. C is wrong because the fruits, called cypselas, form only after the florets are fertilised and are not the colourful part. D is wrong because the seeds lie inside these fruits and are not brightly coloured.
Exam tip: sunflower and marigold = capitulum (head) inflorescence of family Asteraceae: ray florets outside, disc florets inside.
Practice Questions
View allThe fact that the planets move around the Sun, not in circles but in ellipses, was first demonstrated by
- A.Galileo
- B.Martin Luther
- C.Johannes Kepler
- D.Copernicus
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In 1609 Kepler showed that the planets move around the Sun in elliptical orbits, with the Sun at one focus of the ellipse.
Read the full explanation →Which 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.
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