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?

#Question id: 10634

#Unit 10. Ecological Principles

Consider a population which is changing from one generation to the next as per the equation N(t) = R*N(t-1), where N(t) represents the size of the population at time t and R is a constant growth parameter. Under what condition is the population likely to go extinct?

#Question id: 10635

#Unit 10. Ecological Principles

Three important biological parameters – generation time, per capita growth rate (r) and clutch size are a function of the organism‟s body size. Which of the curves (a) or (b) represents the correct relation of each of the parameters to body size?

#Question id: 10636

#Unit 10. Ecological Principles

The demographic transition model depicts demographic changes from high- to low-level births and deaths in five stages

Stage 1 is characterized by total population numbers are low and the high birth rate is balanced by the high death rate.

B) Stage 2 is characterized by high population growth rate is results of high birth rate however, decline death rate

C) Stage 4 is characterized by decline in the proportion of the population in the reproductive age group and these changes stabilizes population size

D) Stage 3 is characterized by falling birth rates and death rates and population growth rate is zero due to the less numbers of people in the reproductive age group

#Question id: 10637

#Unit 10. Ecological Principles

Which of the following graph represent logistic growth pattern and exponential growth respectively? 

#Question id: 10638

#Unit 10. Ecological Principles

Following some statement is given

A- Mortality rate constant over age group 

B- Greater proportional survival at older age

C. Follow type III survivorship curve

D. Follow type II survivorship curve

Which of the following above statement is correct?

#Question id: 10639

#Unit 10. Ecological Principles

The schematic below shows the relationship between survivorship with age (relative to maximum lifespan) in Species 1 (dashed line) and Species 2 (solid line). Which of the following inferences is compatible with this figure?

A) Species 1 follow type I survival ship curve

 B) Species 2 follow type III survival ship curve

 C) Species 1 show parental care of offspring

 D) Species 2 showed large size of offspring than species 1