MCQ
Choanocytes are present in
  • A
    Physalia
  • Sycon
  • C
    Pleurobrachia
  • D
    Echinus

Answer

Correct option: B.
Sycon
b
Choanocytes or collar cells are characteristic cells of porifers/sponges. In sponges, canal and spongocoel are internally lined by choanocytes.

In options, Physalia belongs to cnidaria/coelenterata. Sycon belongs to porifera/sponges.

Pleurobrachia belongs to ctenophora.

Echinus is a sea-urchins and belongs to Echinodermata.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Which one of the following plasma proteins is involved in the coagulation of blood?
Which statement is not correct for drugs abuse ?
(i) Opioid receptors present in our central nervous system and gastro-intestinal tract.
(ii) Cannabinoid receptors present principally in the brain.
(iii) Coca alkaloid has a potent stimulating action on central nervous system.
(iv) Coca alkaloid interferes with the transport of the neuro-transmitter dopamine.
(v) Heroin is a depressant and slows down body functions.
(vi) Morphine is a very effective sedative and painkiller, and is very useful in patients who have undergone surgery.
(vii) Cocaine produces a sense of euphoria and increased energy.
Fossils are
In heavy smokers the alveoli of the lungs are enlarged and damaged which reduces the surface area for the exchange of respiratory gases. This condition is called
Read the following four statements $(A-­D)$.

$(A)$ Colostrum is recommended for the new born because it is rich in antibody.

$(B)$ Chikungunya is caused by a Gram negative bacterium.

$(C)$ Tissue culture has proved useful in obtaining virus­free plants.

$(D)$ Beer is manufactured by distillation of fermented grape juice. How many of the above statements are wrong?

Seed ferns originated in
Which statements are incorrect for mechanisms of nerve impulse conduction along electrical junctions of neuron or electrical synapse ?
(i) Nerve impulse flow directly from one neuron to other across the synapses in electrical synapses.
(ii) Transmission of an impulse across electrical synapses is very similar to impulse conduction along a single axon.
(iii) Impulse transmission across an electrical synapse is always faster than that across a chemical synapse.
(iv) Electrical synapses are rare in our system.
(v) At an electrical synapse, the membranes of the pre and post-synaptic neurons are separated by a fluid-filled space called synaptic cleft is thick.
(vi) Chemicals called neurotransmitters are involved in the transmission of impulses at this synapse.
Reproductive health in society can be improved by
i. introduction of sex education in schools.
ii. increased medical assistance.
iii. awareness about contraception and STDs.
iv. equal opportunities to male and female child.
v. encouraging myths and misconceptions.
Which one of the following techniques is safest for the detection of cancers?
Test tube baby is a technique where: