11. Which among the following is the characteristic feature of virus? (UPSC Prelims 1989)
[A] It is made of fats
[B] It multiplies only on dead animals
[C] It multiplies only on hosts
[D] It lacks chlorophyll
Show Answer
Correct Answer: C [It multiplies only on hosts]
Notes:
They are unique because they are only alive and able to multiply inside the cells of other living things. The cell they multiply in is called the host cell. A virus is made up of a core of genetic material, either DNA or RNA, surrounded by a protective coat called a capsid which is made up of protein.
12. Which branch of biology is deal with the study of seeds?
[A] Embryology
[B] Spermatology
[C] Gerontology
[D] Histology
Show Answer
Correct Answer: B [Spermatology]
Notes:
The study of seeds is known as spermatology. It involves the study in terms of morphology, characteristics and interactions with the environment.
13. Who discovered cell differentiation?
[A] Walther Flemming
[B] Edwin John Butler
[C] Karl Ernst von Baer
[D] Parthasarthy Iyengar
Show Answer
Correct Answer: A [Walther Flemming]
Notes:
Cell differentiation is the process by which dividing cells change their functional or phenotypic type. All cells probably derive from stem cells and acquire their functions when they mature. Walther Flemming discovered cell differentiation.
14. Which of the following organelles is absent in animal cells and present in plant cells?
[A] Cytoplasm
[B] Cell wall
[C] Vacuoles
[D] Mitochondria
Show Answer
Correct Answer: B [Cell wall]
Notes:
The cell wall surrounds the plasma membrane of plant cells. The cell wall is a fairly rigid layer that surrounds a cell located outside the plasma membrane.
15. Cell theory was formulated by __?
[A] Charles Darwin
[B] Theodor Schwann
[C] Robert Hooke
[D] Robert Koch
Show Answer
Correct Answer: B [Theodor Schwann]
Notes:
The classical cell theory was proposed by Theodor Schwann in 1839. There are three parts to this theory. In the first part explains that all organisms are made up of cells. The second part explains that cells are the basic units of life. The third part, explains that cells come from preexisting cells that have multiplied. It was described by Rudolf Virchow in 1858.
16. Green algae, red algae and brown algae are common examples of__?
[A] Thallophyta
[B] Bryophyta
[C] Pteridophyta
[D] Gymnosperms
Show Answer
Correct Answer: A [Thallophyta]
Notes:
Green algae, red algae and brown algae are common examples of Thallophyta.
17. The sporophytic generation is represented only by the zygote__?
[A] Funaria
[B] Chlamydomonas
[C] Pinus
[D] Pinus
Show Answer
Correct Answer: B [Chlamydomonas]
Notes:
Important Features of Chlamydomonas: The plant body is unicellular, pear-shaped, and biflagellate, Each cell typically contains a cup-shaped chloroplast, an eye sac, and two contractile vacuoles, Pamela-stage appearance, Asexual reproduction occurs through biflagellate zoospore formation.
18. Covered smut of Sorghum is caused by which of the following?
[A] Sphacelotheca sorghi
[B] Sphacelotheca cruenta
[C] Sphacelotheca reiliana
[D] Tolyposporium ehrenbergii
Show Answer
Correct Answer: A [Sphacelotheca sorghi]
Notes:
Sporisorium sorghi is a fungus in the family of Ustilaginaceae. It is a plant pathogen that causes the covered scum of sorghum.
19. What are the vegetative parts of a flower?
[A] Sepals
[B] petals
[C] Both 1 & 2
[D] None of these
Show Answer
Correct Answer: C [Both 1 & 2]
Notes:
Sepals and petals are the vegetative parts of a flower.
20. Drying, wilting, and dropping of leaves of a plant due to insufficient water supply, excessive transpiration, or any vascular disease is called
[A] Guttation
[B] Phyllotaxy
[C] Wilting
[D] Phyllode
Show Answer
Correct Answer: C [Wilting]
Notes:
Drying, wilting, and dropping of leaves of a plant due to insufficient water supply, excessive transpiration, or any vascular disease is called Wilting.
