NEET BIOLOGY

Detailed explanation-1: -The endoplasmic reticulum (ER) is a membranous organelle that shares part of its membrane with that of the nucleus. Some portions of the ER, known as the rough ER, are studded with ribosomes and are involved with protein manufacture.

Detailed explanation-2: -In eukaryotes, ribosomes get their orders for protein synthesis from the nucleus, where portions of DNA (genes) are transcribed to make messenger RNAs (mRNAs). An mRNA travels to the ribosome, which uses the information it contains to build a protein with a specific amino acid sequence.

Detailed explanation-3: -Ribosomes are the sites in a cell in which protein synthesis takes place.

Detailed explanation-4: -RNA has three main roles in the cell: It carries the instructions from the DNA in the nucleus to the ribosomes where proteins are made in the cytoplasm of the cell. RNA picks up specific amino acids from the cytoplasm of the cell and delivers them to the ribosomes where protein synthesis takes place.

Detailed explanation-5: -At the nucleolus, a long ribosomal RNA (rRNA) precursor molecule is transcribed from DNA, processed into three mature RNAs, and packaged together with specific proteins to make the large and small ribosomal subunits.