21. A single polar flagellum is known as__?
[A] monotrichous
[B] lophotrichous
[C] amphitrichous
[D] none of these
Show Answer
Correct Answer: A [monotrichous]
Notes:
Monotrichous bacteria have a single flagellum. Lophotrichous bacteria have multiple flagella located at the same location on bacterial surfaces that work together to steer the bacteria in the same direction.
22. In pteridophytes, which of the following is the dominant generation?
[A] gametophytic
[B] haploid
[C] diploid
[D] triploid
Show Answer
Correct Answer: C [diploid]
Notes:
In pteridophytes, the dominant is the diploid sporophytic generation because it develops from the diploid zygote.
23. What are the characteristics of Pteridophyta?
[A] They are cryptogams, seedless and vascular
[B] The plant body has true roots, stem and leaves
[C] Spores develop in sporangia
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Pteridophytes are considered the first plants to develop on land, they are cryptogams, seedless and vascular, the plant body has true roots, stems and leaves, spores develop into sporangia, sporangia in clusters on the sporophyll sex organs are multicellular.
24. When did gymnosperms originate?
[A] Palaeozoic
[B] PreCambrian
[C] Cenozoic
[D] Mesozoic
Show Answer
Correct Answer: A [Palaeozoic]
Notes:
Gymnosperms were the first seed plants to evolve. The earliest seed-like bodies are found in the rocks of the Upper Devonian chain. They appeared in the Paleozoic period and were the dominant plants during the Mesozoic.
25. Megasporangium in Gymnosperms is also called as__?
[A] Macrosporangiate
[B] Nucellus
[C] Microsporangium
[D] Male strobili
Show Answer
Correct Answer: B [Nucellus]
Notes:
Megasporangium in Gymnosperms is also called Nucellus. Megasporangium is the structure in certain spore-bearing plants in which the megaspores are formed.
26. A condition in which the stamens are attached to the petals of a flower instead of directly attached to the thalamus is called__?
[A] Epipetalous
[B] Monadelphous
[C] Staminode
[D] Epiphyllous
Show Answer
Correct Answer: A [Epipetalous]
Notes:
A condition in which the stamens are attached to the petals of a flower instead of directly attached to the thalamus is called Epipetalous. Solanum is an example of Epipetalous.
27. Which of these carry water into a leaf?
[A] Leaf blade
[B] Veins
[C] Chlorophyll
[D] Roots
Show Answer
Correct Answer: B [Veins ]
Notes:
Veins carry water into a leaf. The veins in leaves are made up of two major tissues xylem and phloem.
28. Which of the following is not matched correctly?
[A] Root hair – absorption
[B] Flowers – reproduction
[C] Stem – grows towards light
[D] Chlorophyll – respiration
Show Answer
Correct Answer: D [Chlorophyll – respiration ]
Notes:
Chlorophyll is the natural compound present in green plants that gives them their green colour. It helps plants absorb energy from the sun as they perform photosynthesis.
29. Late blight of tomato is caused by __.
[A] Phytophthora cactorum
[B] Phytophthora cambivora
[C] Phytophthora infestan
[D] Phytophthora citrophthora
Show Answer
Correct Answer: C [Phytophthora infestan]
Notes:
Tomato late blight is caused by the pathogen Phytophthora infestans. Late blight can occur at any time during the growing season when the weather is cool and wet.
30. In which there are two forms of polyp or medusa?
[A] Cnidaria
[B] Platyhelminthes
[C] Aschelminthes
[D] Ctenophora
Show Answer
Correct Answer: A [Cnidaria]
Notes:
In Cnidaria, there are two forms of polyp (sessile and cylindrical) or medusa.
