1. (a) Humans reproduce sexually. (b) Humans are viviparous. (c) Fertilization is internal in human. (d) Male and female gametes are haploid . (e) Zygote is diploid. (f) The process of release of the ovum from a mature follicle is called ovulation. (g) Ovulation is induced by a hormone called the luteiRead more

    (a) Humans reproduce sexually.
    (b) Humans are viviparous.
    (c) Fertilization is internal in human.
    (d) Male and female gametes are haploid .
    (e) Zygote is diploid.
    (f) The process of release of the ovum from a mature follicle is called ovulation.
    (g) Ovulation is induced by a hormone called the luteinizing hormone.
    (h) The fusion of the male and the female gametes is called fertilization.
    (i) Fertilization takes place in the fallopian tube.
    (j) The zygote divides to form blastocyst, which is fertilization implanted in uterus.
    (k) The structure which provides vascular connection between the fetus and uterus is called placenta.

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  2. Dogs and rodents are polyovulatory species. In these species, more than one ovum is released from the ovary at the time of ovulation. Hence, six eggs were released by the ovary of a female dog to produce six puppies. For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/clRead more

    Dogs and rodents are polyovulatory species. In these species, more than one ovum is released from the ovary at the time of ovulation. Hence, six eggs were released by the ovary of a female dog to produce six puppies.

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    https://www.tiwariacademy.com/ncert-solutions/class-12/biology/chapter-3/

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  3. An ovary releases an egg every month. When two babies are produced in succession, they are called twins. Generally, twins are produced from a single egg by the separation of early blastomeres resulting from the first zygotic cleavage. As a result, the young ones formed will have the same genetic makRead more

    An ovary releases an egg every month. When two babies are produced in succession, they are called twins. Generally, twins are produced from a single egg by the separation of early blastomeres resulting from the first zygotic cleavage. As a result, the young ones formed will have the same genetic make- up and are thus, called identical twins.
    If the twins born are fraternal, then they would have developed from two separate eggs. This happens when two eggs (one from each ovary) are released at the same time and get fertilized by two separate sperms. Hence, the young ones developed will have separate genes and are therefore, called non-identical or fraternal twins.

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  4. All human beings have 23 pairs of chromosomes. Human males have 22 pairs of autosomes and contain one or two types of sex chromosome. They are either X or Y. On the contrary, human females have 22 pairs of autosomes and contain only the X sex chromosome. The sex of an individual is determined by theRead more

    All human beings have 23 pairs of chromosomes. Human males have 22 pairs of autosomes and contain one or two types of sex chromosome. They are either X or Y. On the contrary, human females have 22 pairs of autosomes and contain only the X sex chromosome. The sex of an individual is determined by the type of the male gamete (X or Y), which fuses with the X chromosome of the female. If the fertilizing sperm is X, then the baby will be a girl and if it is Y, then the baby will be a boy.
    Hence, it is incorrect to blame a woman for the gender of the child.

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  5. Parturition is the process of giving birth to a baby as the development of the foetus gets completed in the mother’s womb. The hormones involved in this process are oxytocin and relaxin. Oxytocin leads to the contraction of smooth muscles of myometrium of the uterus, which directs the full term foetRead more

    Parturition is the process of giving birth to a baby as the development of the foetus gets completed in the mother’s womb. The hormones involved in this process are oxytocin and relaxin. Oxytocin leads to the contraction of smooth muscles of myometrium of the uterus, which directs the full term foetus towards the birth canal. On the other hand, relaxin hormone causes relaxation of the pelvic ligaments and prepares the uterus for child birth.

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    https://www.tiwariacademy.com/ncert-solutions/class-12/biology/chapter-3/

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