Model Paper 1 — NEET STD 11 Science — Question

In which of the following the placenta forms an important structure in development

During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the plasma membrane has which type of electric change?

Which option is correct for conduction of nerve impulse along chemical synapse ?
(i) At synapse the membranes of the pre and post- synaptic neurons are separated by a fluid-filled space called synaptic cleft.
(ii) Chemicals called neurotransmitters are involved in the transmission of impulses at these synapses.
(iii) The axon terminals contain vesicles filled with these neurotransmitters.
(iv) When an impulse arrives at the axon terminal, synaptic vesicles release their neurotransmitters in the synaptic cleft.
(v) The released neurotransmitters bind to their specific receptors, present on the pre-synaptic membrane.
(vi) Opens ion channels allowing the entry of ions which can generate a new potential in the post- synaptic neuron.
(vii) The new potential developed is only excitatory.

Mesogloea of Coelenterata contains

Choose the wrongly matched option

A bacterial cell was transformed with a recombinant DNA that was generated using a human gene. However, the transformed cells did not produce the desired protein. Reasons could be:

Statement I: Sodium-potassium pump transport 2Na⁺ outwords for 3K⁺ into the cell.
Statement II: The electrical potential difference across the resting plasma membrane is called action potential.

Which of the following is wrongly matched?

Frog which lives on the trees

Identify the site where Wuchereria bancrofti is normally found in human body.