State the role of placenta in the development of embryo.
State the role of placenta in the development of embryo.
The placenta is a specialized disc-like tissue embedded in the uterine wall of the mother. It plays a vital role in the development of the embryo:
- Nutrition and Oxygen Supply: The placenta contains villi on the embryo's side, surrounded by blood spaces on the mother's side. This provides a large surface area for glucose, oxygen, and other essential nutrients to pass from the mother's blood to the developing embryo.
- Waste Removal: The metabolic waste substances generated by the growing embryo are transferred into the mother's blood through the placenta for excretion.
Marking Scheme
- 1Definition/Structure of placenta (disc-like tissue in uterine wall): 0.5 Mark
- 2Role in providing oxygen and nutrients (glucose): 0.75 Mark
- 3Role in removing metabolic waste products: 0.75 Mark
Hint
Think about how a developing fetus gets food and oxygen inside the womb and how it gets rid of waste.
Quick Oral Answer
The placenta is a disc-like tissue in the uterine wall that provides oxygen and nutrients to the embryo and removes metabolic wastes from its blood.
Analysis & Explanation
During pregnancy, the embryo is attached to the uterine wall via the placenta. The structural design of the placenta maximizes the surface area for exchange. Villi on the embryonic side project into maternal blood spaces, facilitating efficient diffusion of oxygen, nutrients, and waste products without direct mixing of maternal and fetal blood.
Common Mistakes
- 1Stating that maternal and fetal blood mix directly. They do not; exchange occurs via diffusion across the placental membrane.
- 2Confusing the placenta with the umbilical cord (the umbilical cord connects the fetus to the placenta).
Interesting Facts
The placenta is a temporary organ. It is the only organ in the human body that is formed, performs its functions, and is then discarded (delivered after the baby is born).
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Frequently Asked Questions
How many marks does this question carry in CBSE Class 10 Science 2012?
This question carries 2 marks in the CBSE Class 10 Science 2012 examination.
Which chapter does this question come from in Science?
This question is from the chapter "How do Organisms Reproduce?" in the CBSE Class 10 Science syllabus.
What topic does this question cover in Science?
This question covers the topic "Sexual Reproduction in Human Beings" from CBSE Class 10 Science.
What type of question is this in the CBSE Class 10 Science 2012 paper?
This is a Short Answer question from Section A in the CBSE Class 10 Science 2012 paper.