___ Tricuspid valve Pulmonary veins

Left ventricle

Lungs

Mitral Valve

___ Venules

___ Pulmonary semilunar valve

Pulmonary arteries

Veins

Right atrium

Right ventricle

Capillaries Aortic semilunar valve

Arteries

Inferior vena cava & superior vena cava

Left atrium

Arterioles

Aorta

Write the number that corresponds to the correct order by tracing the blood flow in correct order.

All ova contain sex chromosomes corresponding to: x y xx xy

Choose the incorrect statement (a) the motor end plate membrane is only capable of generating graded potentials, but it is contiguous with the skeletal muscle sarcolemma, which can generate action potentials. (b) propagation of an action potential through the t-tubules into the sarcoplasmic reticulum triggers the release of ca++ into the cytoplasm of a skeletal muscle fiber. (c) the generation of suprathreshold endplate potentials in multiple muscle fibers could be due to the increased frequency of action potential generation at the axon hillock of a single motor neuron. (d) a greater amount of ach would be found in the presynaptic vesicles of a motor unit that fired several action potentials after exposure to botulinum toxin, than in a motor unit that fired several action potentials after exposure to the venom of the krait snake (which contains α-bungarotoxin).

Why is carbon the backbone of liveing things