STD 11 - 15. Body fluids and criculations — NEET STD 11 Science — Question

Myofibrils are structural constituent of muscle fibre, select correct statement for myofibril :
(i) Each myofibril has alternate dark and light bands on it.
(ii) Striated appearance of myofibril is due to the distribution pattern of two important proteins- actin and myosin.
(iii) The light bands contain myosin and is called I- band or isotropic band, whereas the dark band called A or Anisotropic band contains actin.
(iv) Actin filaments are thicker as compared to the myosin filaments, hence are commonly called thick and thin filaments respectively.
(v) In the centre of each A-band is an elastic fibre called Z-line which bisects it.
(vi) The thick filaments in the A-band are held together in the middle of this band by a thin fibrous membrane called M-line.
(vii) The portion of the myofibril between two successive Z-lines is considered as the functional unit of contraction and is called a sarcomere.

Assertion : During physiology of excretion, deamination does not take place in liver.
Reason : Deamination is a process to make use of excess of amino acids which cannot be incorporated into protoplasm.

At which thoracic vertebra does trachea divide into right and left primary bronchi?

Which is common amongst Fly, Mosquito and Cockroach

Which of the following is not correct for gene?

......... Performs dual function as a primary sex organ as well as an endocrine gland.

Statement I: In testis, the immature male germ cells called spermatogonia produce sperms.
Statement II: Spermatogenesis begins at embryonic stage.