STD 11 - 17. Locomotion and movement — NEET STD 11 Science — Question

Frequency of recombination between gene pairs on same chromosome as a measure of the distance between genes to map their position on chromosome, was used for the first time by

Given statements are characters of muscle, which of the following is correct for cardiac muscles ?
(i) They do not exhibit any striation and are smooth in appearance. Hence, they are called non- striated muscle.
(ii) They have a striped appearance under the microscope and hence are called striated muscles.
(iii) As their activities are under the voluntary control of the nervous system, they are known as voluntary muscles.
(iv) Their activities are not under the voluntary control of the nervous system and are therefore known as involuntary muscles.
(v) They are located in the inner walls of hollow visceral organs of the body like the alimentary canal, reproductive tract, etc.
(vi) They are primarily involved in locomotory actions and changes of body postures.
(vii) Many muscle cells assemble in a branching pattern to form a muscle.

Which of the following is the correct match about the female external genitalia and their functions?

Receptor hormone complex is formed when, the binding of

The vertebra in which the centrum is absent is

Fight­or­flight reactions cause activation of

Which of the following statements are correct ?
(i) Each seminiferous tubule is lined on its inside by two types of cells called male germ cells and Sertoli cells.
(ii) Sertoli cells undergo meiotic divisions and provide nutrition to the germ cells.
(iii) The regions outside the seminiferous tubules called interstitial spaces, contain interstitial cells for secretion of inhibin.
(iv) Leydig cells synthesise and secrete testicular hormones called androgens.
(v) The male sex accessory ducts include epididymis and vas deferens.
(vi) The seminiferous tubules of the testis open into the vasa efferentia through rete testis.