Multiple Choice QuestionsClass Crustacea has following features :
Cephalothorax, book lungs, chitinous exoskeleton
Head and thorax, biramous appendages, book lungs
Head and thorax, book lungs, chitinous exoskeleton
Cephalothorax, biramous appendages, gills
D.
Cephalothorax, biramous appendages, gills
Crustaceans are marine organisms but few live in freshwater or moist places. Their body consists of cephalothorax and abdomen. Each body segment bears a pair of biramous appendages. Respiration occurs through body surface or gills. Excretion occurs through green glands. They bear two pairs of antennae.
Identify the correct statement
In amniotes last nerve is spinal accessory
In non- amniotes last nerve is vagus.
Optic is shortest nerve
Olfactory nerves has mixed fibres.
B.
In non- amniotes last nerve is vagus.
10 pairs of cranial nerves are present in anamniotes (fishes and amphibians) and 12 pairs occur in amniotes (reptiles, birds and mammals). In anamniotes the cranial nerves are- Olfactory, Optic, Occulomotor, Trochlear, Trigeminal, Abducens, Facial, Auditory, Glossopharyngeal and Vagus. In amniotes two more cranial nerves, Spinal accessory and Hypoglossal nerves are present in addition to the above ten.
Hydra receives impulses and stimuli through
nerve net
nematocytes
sensory cells
flame cells
C.
sensory cells
In Hydra sensory cells are found in the gastrodermis. They are supposed to be stimulated by the entry of the prey into the gastrovascular cavity.
Assertion : Salamander, Sphenodon are classified as amphibians.
Reason : Sphenodon is regarded as living fossil.
If both Assertion and Reason are true and Reason is the correct explantion of Assertion
If both Assertion and Reason are true and Reason is not the correct explanation of Assertion
If Assertion is true but Reason is false
If Assertion is false but Reason is true
D.
If Assertion is false but Reason is true
Salamander is a tailed carnivorous and nocturnal amphibian. Sphenodon is a burrowing, carnivorous and nocturnal reptile. It is regarded as a living fossil.
The red colour of 'red sea' is due to which of the following blue-green algae?
Chlamydomonas nivalis
Anabaena
Microcystis
Trichodesmium
D.
Trichodesmium
Trichodesmium is a diazotroph, ie, it fixes atmospheric nitrogen into ammonium, a nutrient used by other organisms.
Red Sea looks reddish because of the presence of cyanobacteria Trichodesmium erythraeum which turns the normaly blue- green water a reddish- brown water.
The sites of the first, second and third moulting of the Ascaris larva are respectively
soil, lung and intestine
liver, stomach and intestine
soil, alveoli and alveoli
soil, intestine and lung
C.
soil, alveoli and alveoli
The development of Ascaris larva takes place outside the body of host in soil and its cleavage starts in shelled eggs. Moulting takes place in soil in shelled egg whereas second and third moulting take place in alveoli of lung. The final moulting takes place in intestine.
A definite number of segments are found in
slug
earthworm
leech
tapeworm
C.
leech
Leech belongs to Phylum- Annelid. A definite number of segments, ie, 33 segments are found in leech.
Ambulacral grooves are absent in the living forms of the Class
Crinoidea
Asteroidea
Ophiuroidea
Echinodermata
C.
Ophiuroidea
Ambulacral grooves are found in the arms of echinoderms lined by tube feet. Ambulacral grooves are absent in Ophiuroidea which are covered by ossicles.
Which of the following Phyla are included in Enterozoa?
Annelida, Mollusca, Porifera
Echinodermata, Hemichordata, Porifera
Mollusca, Arthropoda, Hemichordata
Porifera, Mollusca, Arthropoda
C.
Mollusca, Arthropoda, Hemichordata
Mollusca, Arthropoda, Hemichordata are classified in Plylum- Enterozoa as they are the animals with a digestive tract or cavity.
Which of the following is correct about nematocyst?
It can be re-used.
It is excretory organ in arthropods.
It is ejected on contact and pierce the prey.
None of these.
C.
It is ejected on contact and pierce the prey.
Nematocysts are the stinging cells and are the organs of offence and defence of coelenterates. They contain a poisonous proteinaceous fluid hypnotoxin, alongwith the tube that injects the fluid into the victim. Nemaocysts are activated in response to chemicals secreted by prey. They explode after coming in contact with the prey.
