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Published on: 21/05/2021
QB365 Provides the updated CASE Study Questions for Class 12 Biology, and also provide the detail solution for each and every case study questions . Case study questions are latest updated question pattern from NCERT, QB365 will helps to get more marks in Exams
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Take MCQ Biology Test

1.
Read the following and answer any four questions from (i) to (v) given below:
Human male reproductive system comprises of a pair of testes, primary sex organs associated with formation of gametes and production of sex hormone. Study the given figure of human male reproductive system and answer the following questions.

(i) Which of the following is correct for labelled part P?
| (a) P is rete testis which transports sperms to outside. | (b) P is epididymis which secretes fluid that nourish the sperms | (c) P is epididymis that carry sperms and secretion of seminal vesicles | (d) P is rete testis which lies along inner side of each testis and stores the sperms |
(ii) Identify the correctly matched pair.
| (a) Q - Vasa efferentia | (b) R - Ejaculatory duct | (c) S - Seminal vesicle | (d) T - Cowper's gland |
(iii) Which statement is incorrect for Q?
| (a) It carries spermatozoa from epididymis to ejaculatory duct | (b) Q are only 2 in number. | (c) It arises from rete testis. | (d) It constitutes male sex accessory duct |
(iv) Which structure passes through the prostate gland and carries sperms and secretion of seminal vesicle?
| (a) P | (b) T | (c) S | (d) R |
(v) Assertion: Mucus present in secretion of bulbourethral gland decreases the number of sperms damaged during ejaculation
Reason: Mucus lubricates the end of penis and lining of the urethra.
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Both assertion and reason are false .
2.
Study the flow chart given below and answer the questions that follow:

(a) Name the hormone(s) (in full form) involved in each of the stages, 
(b) Specify the structure in the ovary that is the source of the hormone at stage 
3.

The events in a menstrual cycle are represented above. Answer the following questions based on that.
(a) Why is the phase between 5th and 15th day of menstrual cycle, called
(i) proliferative phase?
(ii) follicular phase?
(b) Mention the ovarian events during the luteal phase.
4.

With reference to the above schematic diagram of (a) Spermatogenesis and (b) Oogenesis, answer the following questions.
(a) About 300 million spermatozoa may be present in a human male ejaculate at one time. Calculate how many primary spermatocytes will be involved to produce this number of spermatozoa .
(b) How many spermatids will be formed?
(c) How many chromatids are found during Oogenesis in
(i) Primary oocyte and
(ii) First polar body in a human female?
5.
Study the following flow chart and answer the questions that follow:

1.
(i) (b) : P is an epididymis that stores the sperms and secretes a fluid which is considered to nourish the sperms
(ii) (b) : Q - Vas deferens, R - Ejaculatory duct S - Bulbourethral gland, T - Seminal vesicle
(iii) (c) :Q (vas deferens) arises from cauda epididymis
(iv) (d)
(v) (a)
2.
(i) 1. Gonadotropin-releasing hormone (GnRH)
2. Follicle-stimulating hormone (FSH) and Luteinising hormone (LH)
3. Progesterone.
(b) Corpus luteum secretes progesterone.
3.
(a) (i) It is called proliferative phase because the endometrium of the uterus is regenerated through prol iferation of its cells.
(ii) It is called follicular phase as the primary follicle in the ovary grows to become a fully mature Graafian follicle under the influence of follicle-stimulating hormone.
(b) (i) Corpus luteum is formed from the remaining parts of the ruptured Graafian follicle.
(ii) Corpus luteum secretes large amounts of progesterone.
4.
(i) 75 million
(b) 300 million
c) (i) 92 chromatids
(ii) 46 chromatids
5.
(a) 1. Gonadotropin-releasing hormone (GnRH)
2. Follicle-stimulating hormone (FSH) Luteinising hormone (LH)
3. Testosterone
(b) (i) Leydig cells secrete testosterone.
(ii) Sertoli cells secrete some factors necessary for spermiogenesis.
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