Multiple Choice QuestionsMetagenesis refers to
Presence of different morphic forms
Alternation of generation between asexual and sexual phases of an organism
Occurrence of a drastic change in form during post-embyonic development
Occurrence of a drastic change in form during post-embyonic development
B.
Alternation of generation between asexual and sexual phases of an organism
Metagenesis is an organisation refers to the reproduction characterised by the alteration of a sexual generation and a generation that reproduces asexually, i.e., alternation of generations.
Cell wall is absent in
Aspergillus
Funaria
Mycoplasma
Mycoplasma
C.
Mycoplasma
True or rigid cell wall is absent in mycoplasm, but their cytoplasm is surrounded by a tri-laminar (triple layered), highly elastic cell membrane of about 10nm in thickness.
The chitinous exoskeleton of arthropods is formed by the polymerisation of
Keratin sulphate and chondraitin sulphate
D-glucosamine
N-acetyl glucosamine
N-acetyl glucosamine
C.
N-acetyl glucosamine
The chitinous exoskeleton of arthropods is formed by the polymerisation of N-acetyl glucosamine, which is a derivative of glucose. It is also a characteristic component of the cell wall of fungi, the radulae of molluscs and the beaks and internal shells of cephalopods including squid and octopuses.
Choose the wrong statement
Penicillium is multicellular and produces antibiotics
Neurospora is used in the study of biochemical genetics
Morels and truffles are poisonous mushrooms
Morels and truffles are poisonous mushrooms
C.
Morels and truffles are poisonous mushrooms
All statements are correct, except statement (c), which can be corrected as
Morels and truffles are edible and members of Ascomycetes in fungi.
A jawless fish, which lays eggs in fresh water and whose ammocoetes larvae after metamorphosis return to the ocean is:
Eptatretus
Myxine
Neomyxine
Neomyxine
D.
Neomyxine
Petromyzon(the lamprey) belongs to the section Agnatha of the sub-phylum-Vertebrata. They have long, greenish brown, cylindrical body with smooth scaleless, slimy skin, jawless mouth, etc. They lay eggs in freshwater but their ammocoete larvae(lower) after metamorphosis return to the ocean.
Which one of the following hormones though synthesised elsewhere, is stored and released by the master gland?
Antidiuretic hormone
Luteinizing hormone
Prolactin
Prolactin
A.
Antidiuretic hormone
Antidiuretic Hormone (ADH) or vasopressin is a peptide hormone synthesised in the hypothalamus, but stored and released from the posterior pituitary lobe.
Destruction of the anterior horn cells of the spinal cord would result in loss of
Sensory impulses
Voluntary motor impulses
Commissural impulses
Commissural impulses
B.
Voluntary motor impulses
Destruction of the anterior horn cells of the spinal cord would result in loss of voluntary motor impulses. It is because the anterior horn cells (also called anterior grey column), which is the front column of grey matter in the spinal cord contains motor neurons that affect the axial muscles.
Roots play insignificant role in absorption of water in
Sunflower
Pistia
Pea
Pea
B.
Pistia
Pistia is a hydrophyte where absorption of water by root is insignificant.
Which one is a wrong statement?
Archegonia are found in Bryophyta, Pteridophyta and Gymnosperms
Mucor has biflagellate zoospores
Haploid endosperm is typical feature of gymnosperms
Haploid endosperm is typical feature of gymnosperms
B.
Mucor has biflagellate zoospores
All the statements are correct except the statement (b). Mucor (fungus) belongs to the class-Zygomycetes. The members of Zygomycetes bear non-motile non-flagellated gametes.
The function of the gap junction is to
performing cementing to keep neighbouring cells together
facilitate communication between adjoining cells by connecting the cytoplasm for rapid transfer of ions, small molecules and some large molecules.
separate two cells from each other
separate two cells from each other
B.
facilitate communication between adjoining cells by connecting the cytoplasm for rapid transfer of ions, small molecules and some large molecules.
A gap junction may nexus or macula communicans. These are specialised intercellular connection between a multitude of animal cell-types. They directly connect the cytoplasm of two cells, which allows various molecules, ions and electrical impulses to directly pass through a regulated gate between cells.
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