In a contracted muscle, which of the following extends from ‘z’ disc to ‘z’ disc?
a) a-band
b) i-band
c) h-zone
d) m-line

The correct answer will be option A - A-band.

Explanation:

The sarcomere is the repeating unit of a myofibril which extends between two z-lines. Under a microscope, a sarcomere can be divided into A- band which is composed of thick myosin only and I-band which consists of thin filament that is actin only.

When a muscle contract then actin and myosin comes in overlapping position due to which I-band shortens and between two z-lines and overlapped structure of thin actin filaments over thick myosin filaments (A-band) is seen.  

Therefore, only A-band is seen between two z-lines in a contracted muscle thus, option A is the correct answer.

x = -6.5

explanation:

with this editor, you should be careful to put what you mean. 5/(2x - 7) = 3/(4x +14) is the way i will interpret it. cross multiply

5*(4x + 14) = 3*(2x - 7)       remove the brackets

20x + 70 = 6x - 21             add 21 to both sides

20x+ 70+21= 6x                 combine

20x + 91 = 6x                     subtract 20x

20x-20x+91=6x-20x           combine

91 = - 14x

x = - 91/14

x = - 6.5

activation of phospholipase c (plc) indirectly increases intracellular ions through inositol triphosphate (ip3).