Cambium is an example of
- A.Lateral meristem
- B.Apical meristem
- C.Intercalary meristem
- D.Permanent tissue
Correct answer
Explanation
The correct answer is A, Lateral meristem. Cambium lies along the sides of stems and roots and its dividing cells increase their thickness, which is the work of a lateral meristem.
Meristems are groups of plant cells that keep dividing. They are named by position. The vascular cambium, between xylem and phloem, adds new xylem inwards and new phloem outwards each season; the cork cambium forms bark. This secondary growth makes trunks thicker, and the yearly layers of xylem it lays down are seen as annual rings in a cut tree.
B is wrong because apical meristem sits at the tips of roots and shoots and increases their length, not girth. C is wrong because intercalary meristem lies at the base of leaves or internodes, as in grasses, and helps those parts grow longer. D is wrong because permanent tissues are made of cells that have stopped dividing and taken up a fixed role, while cambium cells go on dividing.
Exam tip: apical = length, lateral (cambium) = girth, intercalary = growth at the nodes of grasses.
Practice Questions
View allWhich one of the following features is an indication for modification of stem of a plant?
- A.Presence of 'eye' on potato
- B.'Scale' found in onion
- C.'Tendril' found in pea
- D.'Hair' present in carrot
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The eyes of a potato are nodes with buds, and only a stem bears nodes and buds, so they prove that the potato is a modified stem.
Read the full explanation →Which one of the following metals is used in the filaments of photo-electric cells that convert light energy into electric energy ?
- A.Tungsten
- B.Copper
- C.Rubidium
- D.Aluminium
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Rubidium, an alkali metal like caesium, gives off electrons easily when light falls on it, so it is used in photoelectric cells.
Read the full explanation →Tooth enamel is made up of which one of the following calcium compounds ?
- A.Calcium carbonate
- B.Calcium sulphate
- C.Calcium hydroxide
- D.Calcium phosphate
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Tooth enamel is made mainly of calcium phosphate in the form of a hard crystal called hydroxyapatite. Enamel is the hardest substance in the human body, harder even than bone.
Read the full explanation →Which one of the following viruses used to be responsible for highly infectious disease Smallpox ?
- A.Adenovirus
- B.Variola virus
- C.Aichi virus
- D.Coxsackie virus
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Smallpox was caused by the variola virus, a large DNA virus of the pox family that spread from person to person through the air.
Read the full explanation →After fertilization, the fruit and the seed are produced by
- A.ovule and ovary, respectively
- B.ovary and ovule, respectively
- C.ovary, no ovule required
- D.ovule, no ovary required
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After fertilisation the ovary of the flower grows into the fruit, and each ovule inside it develops into a seed.
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