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Question
After how many weeks of pregnancy, a developing embryo inside the mother’s womb is called a foetus?
After how many weeks of pregnancy, a developing embryo inside the mother’s womb is called a foetus?
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Solution
The correct option is B After 8th week
The haploid nuclei of sperm and ovum fuse to form a single-celled diploid zygote. The division starts as the zygote moves through the isthmus part of the oviduct.
The process by which the zygote divides is called cleavage, a rapid special type of mitosis. These rapid mitotic divisions convert the single-celled zygote into a multicellular structure called a blastula.
Cells of the cleavage stage are called blastomeres. Cleavage in a fertilized egg of a human starts in the fallopian tube forming 2, 4, 8, 16 daughter blastomeres.
An embryo with 8-16 blastomeres is known as a morula. The embryo keeps on multiplying by mitotic division and forms a cavity within the cell mass. The cavity is called blastocoel and the embryo is termed the blastocyst. Blastocyst gets implanted into the endometrium and the further development process starts.
The developing embryo has different names in different stages of development, especially in the first few weeks of the pregnancy.
Generally, the stages before implantation is called embryo i.e. from conception until the eighth week of development. After the 8th week, the baby is called a foetus until parturition.
The haploid nuclei of sperm and ovum fuse to form a single-celled diploid zygote. The division starts as the zygote moves through the isthmus part of the oviduct.
The process by which the zygote divides is called cleavage, a rapid special type of mitosis. These rapid mitotic divisions convert the single-celled zygote into a multicellular structure called a blastula.
Cells of the cleavage stage are called blastomeres. Cleavage in a fertilized egg of a human starts in the fallopian tube forming 2, 4, 8, 16 daughter blastomeres.
An embryo with 8-16 blastomeres is known as a morula. The embryo keeps on multiplying by mitotic division and forms a cavity within the cell mass. The cavity is called blastocoel and the embryo is termed the blastocyst. Blastocyst gets implanted into the endometrium and the further development process starts.
The developing embryo has different names in different stages of development, especially in the first few weeks of the pregnancy.
Generally, the stages before implantation is called embryo i.e. from conception until the eighth week of development. After the 8th week, the baby is called a foetus until parturition.
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