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प्रश्न
What is a placenta?
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उत्तर १
The placenta is a special disc-like organ that develops during pregnancy. It establishes a connection between the foetus and the uterine wall through the umbilical cord, enabling the exchange of substances between the mother and the foetus.
उत्तर २
The placenta is a temporary endocrine source that connects the foetus to the expectant mother’s uterine wall, allowing for physiological exchange.
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संबंधित प्रश्न
What are the functions of testes in the human male reproductive system?
What are the organs in humans which produce the gametes?
Mention two functions of human testes.
The diagram shows female reproductive system. Name the parts labelled A to D.
(a) In which part do the sperms enter?
(b) Which part releases the egg?
(c) In which part does fertilisation take place?
(d) In which part does the foetus develop?
Draw a labelled diagram of the human female reproductive system. With the help of this diagram, explain the working of human female reproductive system.
In a flower, the parts that produce male and female gametes are respectively :
(a) sepal and anther
(b) filament and stigma
(c) anther and ovary
(d) stamen and style
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?
Describe the role of the following in human beings:
(i) Seminal vesicles
(ii) Prostate gland
Define the following:
Parthenogenesis
Rewrite the following terms in a correct and logical sequence:
The luteal phase, follicular phase, menstrual phase, ovulatory phase.
