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प्रश्न
The diagram given below shows the early embryonic stages of fish, reptiles, birds and humans. Though adult reptiles, birds and mammals breathe air, their embryos possess gills. How does this fact support evolution?
उत्तर
Embryos show the presence of gills to prove that the ancestors were aquatic. The concept of “ontogeny recapitulates phylogeny”.
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संबंधित प्रश्न
When and where do chorionic villi appear in humans?
Comment on the role of placenta as an endocrine gland.
Eye lens is formed from ______.
Which extra-embryonic membrane in humans prevents desiccation of the embryo inside the uterus?
In the development of the human body, the ectoderm is responsible for the formation of ______.
Relaxin is the hormone secreted by the placenta.
The concentration of which of the following substances will decrease in the maternal blood as it flows from embryo to placenta through the umbilical cord?
The human foetus within the uterus
- Oxygen
- Amino Acids
- Carbon dioxide
- Urea
Which of the following is not a function of the placenta?
hCG is secreted by ______
Draw a diagram showing human foetus within the uterus and label any four, parts in it.
