STD 12 - 8. microbes in human welfare — NEET STD 11 Science — Question

Assertion : In the descending limb of loop of Henle, the urine is hypertonic, whereas in ascending limb of loop of Henle, the urine is hypotonic.
Reason : Descending limb is impermeable to sodium, while ascending limb is impermeable to water.

Tubectomy is a method of sterilization in which

After vaccination the body builds up

What is true for expressing recessive characters

When a person suffers from a marked fall in blood pressure, it is helpful to administer to him the following hormone:

Parturition duct in female is called

In which of the following very simple neural organization is found ?

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.

Statement I: Parasympathetic neural signals increase the heart rate while sympathetic neural signals decrease the heart rate.
Statement II: Adrenal medullary hormones can increse the cardiac output.