Pearl is secreted by the __________ of the pearl oyster.
foot
mantle
gills
None of these
Correct Answer :
B. mantle
Related Questions
Oparin is known for his hypothesis on
origin of species
origin of life
one germ one disease
one gene one enzyme
Which one of the ecosystems Is the largest in the world?
forests
rivers
deserts
oceans
The following disease is prevented by triple-antigen immunization
Diphtheria
Tuberculosis
Smallpox
Mumps
The part of the brain which is responsible for intelligence is
cerebrum
opthalmic
cochlea
semicircular canals
The natural defence of our body against foreign germs is formed by
red corpuscles
white corpuscles
platelets
lymph
Who discovered the electron microscope?
Knoll and Ruska
Rudolf and Kolliker
Robert Hooke
CP Swanson
Vitamins A and C are predominantly present in
brinjal
lady's finger
potato
tomato
Enzymes are produced by
endocrine glands
exocrine glands
liver
spleen
The first person to observe the bacteria, protozoa and spermatozoa under the microscope was
Theodore Schwann
Matthias Schleidon
Robert Hooke
Leuwenhoek
The theory that believes that the first living organism came from another planet is known as
Catastrophism
Special creation
Organic evolution
Cosmozoic theory
The disease Goitre is caused in persons who do not have in their diet sufficient
calcium
sodium
iodine
iron
The nerve messages enter the cell through the
Dendrite
Axon
Cyton
Synapse
Which organism probably arrived first in the world?
Algae
Fungi
Protozoa
None of the above
Savannah is
grass land
desert
forest
snow clad mountains
Which one is called anti-haemorrhagic vitamin?
A
C
E
K
Haemophilia is a hereditary disease carried by
females and expressed by females
females and expressed by males
males and expressed by females
males and expressed by males
Hypogeal germination is found in
castor
onion
bean
bengal gram
Blood clotting requires vitamin
A
B
C
K
The thrombocytes are associated with
blood coagulation
transport of respiratory gases
removal of nitrogenous wastes
All the above
Blood clot Inside blood vessels is prevented by
heparin
fibrinogen
thrombin
prothrombin
The hormone that contains iodine is
Prolactin
Vasopressin
Thyroxine
Adrenalin
The scientist who discovered the blood groups is
Landsteiner
TH Morgan
William Harvey
Darwin
The energy for the sperm to swim and reach the egg is provided by
tail
head
neck
mitochondria
The bone cells are connected with each other by
Haversian canal
canaliculi
capillaries
matrix
The association between leguminous plants and bacteria is
parasitic
saprophytic
symbiotic
None of the above
The stones formed in human kidney consist mostly of
calcium oxalate
sodium acetate
magnesium
calcium
Tetrodotoxin is a potent poison that
erodes blood vessels
blocks conduction of nerve impulses causing respiratory paralysis
produces damage to the kidneys
produces intestinal bleeding
From the end of the Triassic to the cretaceous period the earth was ruled by
eurypterids
cotylosaurs
dinosaurs
mammals
Green plants In the sea are useful for respiration of flash because they
release oxygen
release carbon dioxide
release oxygen and carbon dioxide simultaneously
take oxygen and give out carbon dioxide
The tear glands help us in
sobbing
protecting the eye
preventing dust
providing a clean moist surface