Question 82 marksShort AnswerSection A

State the role of placenta in the development of embryo.

How do Organisms Reproduce?
Sexual Reproduction in Human Beings

Official answer

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:


  1. 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.
  2. Waste Removal: The metabolic waste substances generated by the growing embryo are transferred into the mother's blood through the placenta for excretion.
Answer keywords:placentadisc-like tissueuterine wallvilliglucoseoxygenwaste removalmother's blood

Marking scheme

  1. 1.Definition/Structure of placenta (disc-like tissue in uterine wall): 0.5 Mark
  2. 2.Role in providing oxygen and nutrients (glucose): 0.75 Mark
  3. 3.Role 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.

Common mistakes

  1. 1.Stating that maternal and fetal blood mix directly. They do not; exchange occurs via diffusion across the placental membrane.
  2. 2.Confusing the placenta with the umbilical cord (the umbilical cord connects the fetus to the placenta).

Analysis and 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.

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).

Question details

Q8 of 41 questions

Board
CBSE
Class
Class 10
Subject
Science
Year
2012
Section
Section A
Marks
2
Type
Short Answer
Chapter
How do Organisms Reproduce?
Topic
Sexual Reproduction in Human Beings
Bloom's level
Understanding
Syllabus topic
Human reproduction: Role of placenta

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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.