Unit of alternating light and dark striations between z discs (lines)

Sarcomere.

Explanation:

Sarcomere is responsible for the striation of the skeletal and cardiac muscle. The striation was first described by the scientist Van Leeuwenhoek.

Sarcomere may be defined as the basic unit of the striated muscle tissue. This is the repeating unit of two Z lines alternating between the dark and light bands of the striated muscle.

Thus, the answer is sarcomere.

5. method

15. communicate, transport

18. component

21. learn

22. preceding

23. display

24. area

25. anomalous, unusual, unconventional

violet light has a shorter wavelength than blue light. violet light is scattered more than blue light. however, the human eye is less sensitive to violet than to blue. as a result, we perceive a blue sky instead of a violet sky.