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Human Reproduction — BIOLOGY STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceBIOLOGYHuman Reproduction1 Mark
Question
For two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  1. Both assertion and reason are true, and reason is the correct explanation of assertion.
  2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
  3. Assertion is true, but reason is false.
  4. Both assertion and reason are false.
Assertion: Man does not urinate and ejaculate at the same time.
Reason: Membranous and penile part of urethra forms the outflow pathway for the urine and for the seminal fluid.
✓

Answer

  1. Both assertion and reason are true, but reason is not the correct explanation of assertion.

Explanation:

Urethra leads from urinary bladder through the prostate gland and into the penis. It consists of four parts - urinary, prostatic, membranous and penile. The urethra (membranous and penile part) in the male forms the outflow pathway for the urine and for the seminal fluid. However, it is physically impossible for a man to urinate and ejaculate at the same time because just prior to ejaculation the internal sphincter closes off the opening of the urinary bladder. The sphincter does not relax until the ejaculation is completed. The closing of this internal sphincter prevents urine from entering the urethra and also prevents the backflow of ejaculatory fluid into the urinary bladder.

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