Please explain why the answer is correct,

1.Based on what you know about chemical equilibria in biological systems, identify which situation(s) will be irreversible: (1) ADP + Pi to make ATP (2) complete glucose decomposition to CO2 and H2O (3) H2O + CO2 to make H2CO3  

(a) 1 and 3 (b) 2 only (c) 1 only (d) 3 only (e) 2 and 3  

2.Which of the following defines the term competition? a) movement of molecules by the use of vesicles b) carrier transport of a group of closely related molecules the energy required to move molecules c) a group of carrier proteins operating at their maximum rate d) a carrier protein can bind different but chemically similar substrates 

3.Each statement below is true about epithelia, except one. Identify the exception.  a) Epithelial tissues may be simple or stratified, and occur in three cell shapes: squamous, cuboidal, and columnar.  b) Epithelia are distinguished by their extensive extracellular matrix.  c) Epithelial cells retain the ability to divide and reproduce throughout their lifespan, even though some may live only a few days.  d) Epithelia have a thin layer, called the basal lamina, that lies between the epithelium and the underlying tissues.  e) Epithelial junctions may be classified as either leaky or tight.

4.Functions of the skin do NOT include  a) housing sensors to monitor environmental conditions.  b) maintaining body temperature.  c) maintaining body pH d) preventing dehydration.  e) protection from bacteria or other pathogens.  

5. In the nervous system, there are actually _________ glial cells compared to neurons. a) many more b) about the same number of c) twice as many d) half as many e) far fewer 

6.Each of these is a true statement about acetylcholine except one. Identify the exception. a) It is synthesized from the precursors acetyl coenzyme A and choline. b) Acetylcholine is completely degraded to CO2 and H2O in the postsynaptic cell. c) Synthesis of acetylcholine occurs in the axon terminal. d) The enzyme acetylcholinesterase destroys acetylcholine in the synaptic cleft. e) Each of these statements is true.  

7.In order to release more neurotransmitter onto the postsynaptic cell, the presynaptic cell would have to __________. a) do nothing; no change is possible since the all-or-none law is in effect b) "fire" action potentials with higher voltage (higher amplitude) c) "fire" action potentials with longer durations d) "fire" action potentials with higher frequency e) none of the above 

8.Long-term potentiation (LTP) a) is an example of synaptic plasticity. b) results in increased release of and sensitivity to glutamate at the synapse. c) can occur at a glutaminergic synapse containing postsynaptic AMPA and NMDA receptors. d) requires postsynaptic depolarization to occur. e) all of the above 

9.Interruption of the supply of which of these can have devastating effects to the brain? a) blood b) glucose c) oxygen d) all of the above