Neurones, Synapses and Drug Action：練習問題

Which enzyme is used in gene technology to join two fragments of DNA together by forming phosphodiester bonds?

During the transmission of a nerve impulse along a myelinated axon, how does saltatory conduction increase conduction velocity?

An investigator applies repeated non-harmful tactile stimuli to the siphon of a sea slug (Aplysia) and observes habituation of the gill withdrawal reflex. Which cellular mechanism accounts for this reduced response?

Which plant hormone stimulates the production of amylase in the aleurone layer of germinating cereal grains?

Which of the following occurs in a rod cell of the mammalian retina when it is in the dark?

State the specific function of Schwann cells in the structure of a motor neurone.

Describe how the binding of acetylcholine to receptors on the post-synaptic membrane initiates a new nerve impulse.

Explain the molecular mechanism by which rhodopsin responds to light to trigger hyperpolarisation in rod cells.

The human brain consists of several specialized regions.

(a) Identify the region of the brain responsible for thermoregulation and osmoregulation.

(b) Describe the primary function of the cerebellum.

Plants utilize complex signaling pathways involving hormones and photoreceptors to coordinate their growth in response to environmental changes.

(a) Describe the interconversion of the two forms of phytochrome, \(P_{r}\) and \(P_{fr}\), and explain which form triggers seed germination in many species. (3)

(b) Explain the mechanism by which auxin (IAA) causes the elongation of cells on the shaded side of a plant shoot during a phototropic response. (2)