Biology Today — January 2018

(Jacob Rumans) #1

(b) If both A and R are true but R is not the correct explanation of A.
(c) If A is true but R is false.
(d) If both A and R are false.



  1. Assertion : Sertoli cells concentrate testosterone in the
    seminiferous tubules.
    Reason : Sertoli cells secrete androgen binding protein.

  2. Assertion : Vasa efferentia arise as fine ciliated ductules from
    rete testis.


Reason : Vasa efferentia carry sperms from cauda epididymis
to ejaculatory duct.



  1. Assertion : The presence of fructose in female’s genital
    tract confirms sexual intercourse.
    Reason : Secretions of seminal vesicles contain fructose,
    hormones and clotting proteins.

  2. Assertion : During maturation phase of spermatogenesis,
    the spermatids get transformed into mature sperms.
    Reason : The process of transformation of spermatids into
    spermatozoa is called spermiation.

  3. Assertion : Mitochondrial spiral in middle piece of sperms
    provides energy for their movement.


Reason : The axial filament remains surrounded by
cytoplasm in the main piece.


Short Answer Type Questions



  1. Fill in the blanks.
    (i) Endocrine part of testis is represented by .
    (ii)
    are present in between the germinal
    epithelial cells of seminiferous tubules.
    (iii) The collection of fluid in the tunica vaginalis of testis is
    called ___.

  2. How are vasa efferentia and vasa deferentia different from
    each other?

  3. Illustrate the hormonal control of male reproductive system
    with the help of diagrammatic representation.

  4. Write a short note on seminal vesicles.


ANSWER KEY


New MCQs


  1. (c) 2. (a) 3. (a) 4. (d) 5. (d)

  2. (d) 7. (b) 8. (d) 9. (c) 10. (c)

  3. (b) 12. (b) 13. (a) 14. (b) 15. (a)


Exam Section


  1. (d) 2. (d) 3. (d) 4. (a) 5. (c)

  2. (b) 7. (b) 8. (d) 9. (b) 10. (d)

  3. (c) 12. (a) 13. (a) 14. (c) 15. (a)


Assertion & Reason


  1. (a) 2. (c) 3. (a) 4. (d) 5. (b)


Short Answer Type Questions


  1. (i) Leydig’s cells, (ii) sertoli cells, (iii) inguinal hernia

  2. The differences between vasa efferentia and vasa deferentia
    are given below :
    Vasa efferentia Vasa deferentia
    (i) They arise from the
    rete testis.


They arise from the
cauda epididymis.
(ii) They vary from 15 to
20 in number.

They are only 2 in
number.
(iii) They are fine. They are thick.
(iv) Their lining bears many
ciliated cells.

Their lining has many
stereocilia.
(v) They carry spermatozoa
from the rete testis to
the epididymis.

These carry
spermatozoa from
cauda epididymis to the
ejaculatory duct.


  1. The hormonal control of male reproductive system is :
    Hypothalamus


Anterior lobe of
Pituitary gland

Inhibition

Inhibition

Inhibin

Spermatogenesis

Maintain
secondary
sexual
characteristics

Inhibition

Inhibition
GnRH

Leydig’s
cells

LH

Sertoli
cells

FSH

Testosterone


  1. Seminal vesicles are a pair of elongated (5 cm), muscular
    and sacculated glands situated in the pelvis between the
    bladder and rectum. The ducts of seminal vesicles join the
    vasa deferentia to form ejaculatory ducts. They produce an
    alkaline secretion that forms about 60-70% of semen. The
    pH of seminal fluid is 7.4. It helps to neutralise the acidity
    of vaginal tract, thus prolonging the lifespan of sperm. The
    secretion of seminal vesicles are
    (i) Fructose : Provide nutrient energy for sperms.
    (ii) Prostaglandins : Stimulate uterine contractions that
    help the sperm to propel towards female’s oviduct.
    (iii) Clotting proteins : Facilitates coagulation of semen
    after ejaculation.
    

Free download pdf