Question

1a.

A spliceosome will be found in

	a.	prokaryotic cells only
	b.	eukaryotic cells only
	c.	both eukaryotic and prokaryotic cells

1b.

Which type of RNA is found only in eukaryotes?

	a.	mRNA
	b.	tRNA
	c.	rRNA
	d.	none of the above
	e.	all of the above

Answer 1

1a. Spliceosome is a protein complex involved in the removal of intron from pre-mRNA.

these spliceosomes are like-

U1, U2, U4, U5 and U6 found in eukaryote.

Eukaryote have intron I n their genome hence when pre-mRNA are processed then these introns are removed from the pre-mRNA with the help of spliceosome.

These spliceosome recognizes splicing site and cleave mRNA from splicing site and removes intron.

Because Prokaryote lacks intron in their genome, hence there are no need of spliceosome in Prokaryote.

Option b is correct.

1b.

mRNA is messenger RNA transcribed from the DNA which has non overlapping coding sequence termed as codon.

Means this carry genetic information in the form of codon.

These codons are recognized by tRNA (transfer RNA) which transfers amino acids to the synthesizing polypeptide chain on the ribosome.

rRNA is a part of ribosome ( present in ribosome) .

It performs binding of ribosome to the mRNA on specific position (translation start site) and also has peptidal transferase activity.

Hence All three RNAs mRNA, tRNA, and rRNA are present in eukaryote.

Option e  is correct.