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From a newly fertilized mouse egg, maternal pronucleus was removed and replaced with a second paternal pronucleus. Following observations/statements w
Question

From a newly fertilized mouse egg, maternal pronucleus was removed and replaced with a second paternal pronucleus. Following observations/statements were made:
A. This will result in formation of an androgenetic embryo.
B. This will result in formation of a gynogenetic embryo.
C. The embryo will not survive beyond mid-gestation since parental genomes serve distinct complementary functions due to variable imprinting pattern.
D. The adult originating from the embryo will be a clone of the father.
E. The embryo will develop as adult but will die early due to rapid shortening of the telomeres.

Which one of the following represents the correct combination of above statements?

A.

A, B, C

B.

B, C, E

C.

A and C only

D.

A and E only

Correct option is C

Explanation-

Statement A - This will result in formation of an androgenetic embryo  - CORRECT
An androgenetic embryo contains only paternal genomes, which is exactly what happens when you remove the maternal pronucleus and insert another paternal pronucleus.
Statement B - This will result in formation of a gynogenetic embryo  - INCORRECT
 A gynogenetic embryo contains only maternal genomes. This situation has no maternal genome, so this cannot be correct.
Statement C - The embryo will not survive beyond mid-gestation since parental genomes serve distinct complementary functions due to variable imprinting pattern   - CORRECT
 This reflects a key concept in genomic imprinting. Both maternal and paternal genomes are required for normal development because certain genes are only expressed from one parental allele. Embryos with only paternal (androgenetic) or only maternal (gynogenetic) genomes typically fail mid-gestation due to imprinting defects.
Statement D -  The adult originating from the embryo will be a clone of the father  -  INCORRECT
While the genome is paternal, development fails mid-gestation, so no adult will form. Also, imprinting and epigenetic states complicate true "cloning."
Statement E -  The embryo will develop as adult but will die early due to rapid shortening of the telomeres   - INCORRECT
Telomere shortening isn't the cause of embryonic failure here. The embryo won't reach full development because imprinting imbalance causes early lethality.

 Correct Answer: A and C only (Option c)

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