TLS Online TPP Program

#Question id: 7309


Following statements are regarding to the molecular basis of the coincidence model in Arabidopsis.

A. In Arabidopsis under short days, there is little overlap between CO mRNA expression and daylight.

B. CO protein does not accumulate to sufficient levels in the phloem to promote the expression of the transmissible floral stimulus and the plant remains vegetative.

C. Under long days, the peak of CO mRNA abundance (at hours 12 through 16) overlaps with daylight (sensed by phyA and cryptochrome [cry]), allowing CO protein to accumulate.

D. CO activates FLC mRNA expression in the phloem, which causes flowering when the FT protein is translocated to the apical meristem.

Which of the following is incorrect?

#Unit 5. Developmental Biology
  1. A and C
  2. B only
  3. C only
  4. D only
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TLS Online TPP Program

#Question id: 11212

#Unit 7. System Physiology – Animal

The activity of acetylcholine in a synapse is terminated by its ________.

TLS Online TPP Program

#Question id: 11211

#Unit 7. System Physiology – Animal

The following steps refer to various stages in transmission at a chemical synapse.


1. Neurotransmitter binds with receptors associated with the postsynaptic membrane.


2. Calcium ions rush into neuron's cytoplasm.


3. An action potential depolarizes the membrane of the presynaptic axon terminal.


4. The ligand-gated ion channels open.


5. The synaptic vesicles release neurotransmitter into the synaptic cleft.


Which sequence of events is correct?

TLS Online TPP Program

#Question id: 11210

#Unit 7. System Physiology – Animal

An inhibitory postsynaptic potential (IPSP) occurs in a membrane made more permeable to ________.

TLS Online TPP Program

#Question id: 11209

#Unit 7. System Physiology – Animal

Acetylcholine released into the junction between a motor neuron and a skeletal muscle binds to a sodium/potassium channel and opens it. This is an example of ________.

TLS Online TPP Program

#Question id: 11208

#Unit 7. System Physiology – Animal

Neurotransmitters are released from axon terminals via ________.

TLS Online TPP Program

#Question id: 11207

#Unit 7. System Physiology – Animal

In multiple sclerosis, the myelin sheaths around the axons of the brain and spinal cord are damaged and demyelination results. How does this disease manifest at the level of the action potential?

 I) Action potentials move in the opposite direction on the axon.

 II) Action potentials move more slowly along the axon.

 III) No action potentials are transmitted.