11. In Mycorrhiza, symbiotic association occurs between which of the following organisms? (UPSC Prelims 1990)
[A] Bacteria and roots of higher plants
[B] Algae and roofs of orchids
[C] Fungi and roots of higher plants
[D] Protozoa and roots of higher plants
Show Answer
Correct Answer: C [Fungi and roots of higher plants]
Notes:
Mycorrhiza is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant’s rhizosphere, its root system.
12. Which pigment is responsible for the colour of healthy skin in human beings?
[A] Bilirubin
[B] Haemoglobin
[C] Melanin
[D] Progesterone
Show Answer
Correct Answer: C [Melanin]
Notes:
The single most factor responsible for the cpolour of the skin is the pigment melanin. It is secreted by the melanocytes within the skin.
13. What are cryptogamous plants?
[A] Flowerless plant
[B] Seedless Plant
[C] Reproduce by spores
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Cryptogamic plants include Algae, mosses, liverworts, lichens, ferns and fungi and they reproduce by spores and not producing flowers or seed.
14. Which of the following is true for chromatin?
[A] These are highly condensed DNA
[B] It is found in the nucleus
[C] It contains a single dsDNA
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Chromatin is a complex of DNA and proteins that make up chromosomes within the nucleus of eukaryotic cells.
15. Which of the following are the most primitive vascular plants?
[A] Mosses
[B] Cycads
[C] Kelps
[D] Ferns
Show Answer
Correct Answer: D [Ferns]
Notes:
A fern is a member of a group of vascular plants. It reproduces by means of spores and has neither seeds nor flowers.
16. Which of the following is a characteristic of Kingdom Plantae?
[A] They are non-motile
[B] They make their own food hence are called autotrophs
[C] It contain photosynthetic pigments called chlorophyll present in the plastids
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
The Plant Kingdom has the following distinctive features:They are motionless, they make their own food, hence they are called autotrophs, they reproduce asexually by vegetative propagation or sexually, these are multicellular eukaryotes, the plant cell has an outer cell wall and a large central vacuole, Plastids in plants contain photosynthetic pigments called chlorophyll, they have separate organs for anchoring, reproduction, support and photosynthesis.
17. Volvox is a common example of which of the following?
[A] Thallophyta
[B] Bryophyta
[C] Pteridophyta
[D] Angiosperms
Show Answer
Correct Answer: A [Thallophyta]
Notes:
Volvox is a common example of Thallophyta.
18. Agar is obtained commercially__?
[A] Blue-green algae
[B] Red algae
[C] Brown algae
[D] Green algae
Show Answer
Correct Answer: B [Red algae]
Notes:
Agar is a jelly-like material obtained from red algae. The jelly content in algae is due to the presence of non-branched polysaccharides derived from the cell wall of red algae.
19. Venation is a term used to describe the pattern of arrangement.
[A] Flowers in inflorescence
[B] Veins and veinlets in a lamina
[C] Floral organs
[D] All of these
Show Answer
Correct Answer: B [Veins and veinlets in a lamina]
Notes:
The arrangement of veins and veins on the septum of the leaf is called venation.
20. What is the arrangement of ovules inside the ovary called?
[A] Aestivation
[B] Placentation
[C]
Hibernation
[D] Fragmentation
Show Answer
Correct Answer: B [Placentation]
Notes:
The arrangements of ovules within the ovary are known as placentation.
