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Assertion: All copulations do not lead t...

Assertion: All copulations do not lead to the fertilisation and pregnance.
Reason: Fertilisation can occur only if the ovum and sperms are transported simultaneously to the ampullary isthmic junction.

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Fertilisation can only occur if the ovum and sperms are tranported simultaneously to the ampullary-isthmic junction and ovum is released only once a month. This is one of the reasons why all copulations do not lead to fertilisation and pregnancy.
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Read the following text and answer the following questions on the basis of the same: During sexual reproduction, the male inserts the sperm into the female reproductive tract, and sperm receive by the ovary and after that sperm fuse with the egg (ovum) in the ampullary region, this process is called fertilization, haploid nucleus of sperm fuse with that of ovum to form Diploid zygote. Assertion (A): All copulations do not lead to the fertilisation and pregnancy. Reason (R): Fertilisation can occur only if the ovum and sperms are transported simultaneously to the ampulllary-isthmic junction.

Assertion: All copulations cannot lead to fertilisation and pregnancy. Reason: Fertilisation can only occur if the ovum and sperms are transported simulaneously to the ampullary region.

A : All copulations do not lead to fertilisation and pregnancy . R : Fertillsation can occur if the ovum and sperms are transported simultaneously to the ampullary - isthmic junction

From a to d which of the following statements are correct ? (a) Fertilisation can occur only if the ovum and sperm are transported simultaneously to the ampullary isthmic junction (b) First movement of foetus and appearance of hair on head are usually observed during the fifth month of pregnancy . (c) On 14^(th) day of Menstrual cycle , the level of progesterone is maximum . (d) The signals for parturition originate from fully developed foetus and placenta

Why do all copulations not lead to fertilisation and pregnancy ? The root cause is ______

which of the following statements regarding fertilization and implantation are incorrect ? I. During fertilization , a sperm first comes in contact with the corona radiata cells produced by the ovum. II. Fertilization occurs only if sperm and ovum are simultaneously transported to the ampullary region. III. Implantation occurs about 7 days after fertilization . IV. The continuous division of morula leads to the formation of zygote.

Assertion . Female gametophyte in angiosperm is eight nucleate . Reason. Double fertilisation occurs in angiosperm .

Menstruation only occurs if the released ovum is not fertilised. Why?

A : Lack of menstruation may be indicative of pregnancy R : Menstruation only occurs if the released ovum is fertilised

NCERT FINGERTIPS-HUMAN REPRODUCTION-Human Reproduction
  1. The vas deferens receives duct from the seminal vesicle and opens into...

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  2. Urethral meatus refers to the

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  3. Mourla is a developmental stage

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  4. The membranous cover of the ovum at ovulation is

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  5. Identify the odd one from the following.

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  6. Assertion: A drop in temperature does not affect spermatogensis. Rea...

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  7. Assertion: The regions outside the seminiferous tubules are called int...

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  8. Assertion: Each seminiferous tubule is lined on its inside by three ty...

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  9. Assertion: Infundibulum is a funnel shaped part closer to ovary. Rea...

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  10. Assertion: The shape of the uterus is like an inverted pear. Reason:...

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  11. Assertion: The endometrium undergoes cyclical changes during menstrual...

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  12. Assertion: The female external genitalia includes mons pubis, labia ma...

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  13. Assertion: The type B spermatogonia are called primary spermatocytes. ...

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  14. Assertion: The middle piece is called as power house of the sperm. R...

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  15. Assertion: Human male ejaculates about 5-100 million sperms during a c...

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  16. Assertion: All copulations do not lead to the fertilisation and pregna...

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  17. Assertion: All embryo with 8 to 16 blastomeres is called a morula. R...

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  18. Assertion: After implantation, finger-like projections appear on the t...

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  19. Assertion: During pregnancy the levels of hormones like estrogens and ...

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  20. Assertion: Vigorous contraction of the uterus at the end of pregnancy ...

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