Which one of the following statements about bryophytes is not correct ?
- A.The plant body is a gametophyte.
- B.They are also called the amphibians of plant kingdom.
- C.The plant body is attached to the substratum by rhizoids.
- D.Specialized water-conducting tissues are present.
Correct answer
Explanation
The correct answer is D, Specialized water-conducting tissues are present. This statement is wrong because bryophytes, the mosses and liverworts, have no true vascular tissue: they lack xylem to carry water and phloem to carry food. Water simply moves from cell to cell, which is one reason these plants stay small and grow in damp, shady places. Vascular tissue appears first in the pteridophytes, such as ferns. Option A is correct as a statement, so it is not the answer: the main, independent plant body of a bryophyte is the haploid gametophyte, and the sporophyte grows on it and depends on it. Option B is also correct: they are called the amphibians of the plant kingdom because they live on land but need water for fertilisation, as their sperm must swim to the egg. Option C is correct too: in place of true roots, bryophytes are anchored to soil, rock or bark by thin, hair-like rhizoids. Exam tip: bryophytes = gametophyte dominant, rhizoids, no xylem or phloem, need water for fertilisation; pteridophytes = first vascular plants.
Practice Questions
View allChlorophyll in photosynthetic prokaryotic bacteria is associated with
- A.plastids
- B.membranous vesicles
- C.nucleoids
- D.chromosomes
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Photosynthetic bacteria have no chloroplasts; their pigments sit on infoldings of the cell membrane that form vesicles or sacs, often called chromatophores.
Read the full explanation →Fat in human body is stored in
- A.Adipose tissue
- B.Red blood cells
- C.Muscle tissue
- D.Epithelial tissue
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Adipose tissue is a loose connective tissue whose cells, called adipocytes, are built to store fat. Each cell holds a large droplet of fat that pushes the nucleus and cytoplasm to one side.
Read the full explanation →Which one of the following is a metalloid ?
- A.Germanium
- B.Coke
- C.Iodine
- D.Sugar
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Germanium is a metalloid, an element whose properties lie between those of metals and non-metals. It is a hard, shiny, grey-white solid like a metal, yet it is brittle and conducts electricity far less well than a metal, which makes it a semiconductor.
Read the full explanation →A photon of X-ray has energy of 1 keV. A photon of visible radiation has energy of 3 eV. In this context, which one of the following statements is not correct?
- A.The wavelength of X-ray photon is less than the wavelength of visible radiation photon.
- B.Both the photons have different energies.
- C.The speeds of both the photons in vacuum are different.
- D.The frequency of X-ray photon is higher than the frequency of visible radiation photon.
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This statement is wrong because every photon, whatever its energy, travels in vacuum at the same speed of light, about 3 × 10^8 metres per second.
Read the full explanation →Which of the following substances cause temporary hardness in water?
1. Mg(HCO3)2
2. Ca(HCO3)2
3. CaCl2
4. MgSO4
Select the correct answer using the code given below.
- A.3 and 4
- B.2 and 3
- C.1 and 4
- D.1 and 2
Show answer
Temporary hardness is caused by the bicarbonates of magnesium and calcium, Mg(HCO3)2 and Ca(HCO3)2. It is called temporary because simple boiling removes it: on heating, the soluble bicarbonates break down into insoluble carbonate or hydroxide, carbon dioxide and water, and the solid settles out.
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