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In human beings , the hollow ball of cel...

In human beings , the hollow ball of cells called a , about b days after fertilisation , burrows into the lining of uterus event called implantation. Blanks a , b respectively are

A

Morula, six

B

Blastula , seven

C

Blastocyst seven

D

Gastrula , seven

Text Solution

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The correct Answer is:
To solve the question, we need to identify the correct terms that fit into the blanks labeled as A and B. 1. **Understanding the Question**: The question states that in human beings, a hollow ball of cells called A, about B days after fertilization, burrows into the lining of the uterus in a process called implantation. 2. **Identifying Blank A**: - The hollow ball of cells that forms after fertilization is known as a **blastocyst**. - Before the blastocyst stage, the fertilized egg goes through several stages, including the morula stage, but it is the blastocyst that is specifically referred to as the hollow ball of cells. 3. **Identifying Blank B**: - Implantation occurs typically around 5 to 9 days after fertilization. - The most common reference point is around **7 days** after fertilization when the blastocyst implants into the uterine lining. 4. **Final Answer**: - Therefore, the correct terms for the blanks are: - A = **Blastocyst** - B = **7** Thus, the complete statement would read: "In human beings, the hollow ball of cells called a **blastocyst**, about **7** days after fertilization, burrows into the lining of the uterus in an event called implantation."
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