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प्रश्न
Explain why, a human zygote is more likely to grow into an adult than a frog zygote.
उत्तर
In humans, fertilisation is internal. The zygote divides and forms the embryo which is implanted in the uterus. This embryo receives all the nutrients and care from the mother's body and develops into an adult.
In frogs, fertilisation is external and the zygote is formed outside the body. Thus, it forms a larva instead of developing directly into an adult.
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संबंधित प्रश्न
Write the functions of the following parts in human female reproductive system:-
(i) Ovary
(ii) Oviduct
(iii) Uterus
What could be the reasons for adopting contraceptive methods?
What are the male sex cells in humans called?
Write the names of male sex hormone?
The ratio of the number of chromosomes in a human zygote and a human sperm is ______
When a human female reaches a certain age then vaginal bleeding occurs for a few days after regular time intervals.
(a) What is this process known as (i) in scientific terms, and (ii) in everyday language?
(b) At what approximate age this process starts in human females? When is the human female said to have attained at this stage?
(c) After how much time is this process repeated? For how many days does this process usually last?
(d) What does the onset of this process in human females signify?
(e) At which particular event in the life of a human female does this process stop temporarily but start again?
(f) At which approximate age of human female does this process stop permanently?
The germ cell A produced by a person X is round in shape and it fuses with another germ cell B having a long tail and produced by a person Y. The fusion of A and B produces a new cell C. The cell C divides repeatedly and grows inside the organ D of person X to form E in which the body features of the unborn baby are not much developed. E grows further to form F in which the various body features of the unborn baby (like hands, legs, head, eyes, and ears, etc.) can be identified. F grows further and ultimately forms a baby. What are A, B, C, D, E and F? Out of the two persons X and Y, which one is male and which one female?
Fill in the blank.
Pollen grains are formed by ______ division in locules of anthers.
Which one of the following statements about human sperm is correct?
Mention any two changes that are common to both boys and girls in early teenage years.
