Molecular Basis of Inheritance Mind Map

DNA and RNA are polynucleotides made of nucleotide units; DNA usually forms a double helix with two antiparallel complementary strands, while RNA is usually single-stranded and contains ribose sugar and uracil.

In structure questions, mention nucleotide components, phosphodiester bonds, complementary base pairing, antiparallel polarity, and Chargaff's rule.

DNA packaging is the folding of long DNA molecules with histone proteins into nucleosomes and higher-order chromatin so that DNA fits inside the nucleus and remains functionally organized.

Mention histone octamer, nucleosome, linker DNA, chromatin, and euchromatin-heterochromatin difference when writing a complete answer.

The search for genetic material refers to experimental evidence showing that DNA carries hereditary information in most organisms, mainly through transformation and bacteriophage experiments.

Write experiments in chronological logic: Griffith observed transformation, Avery identified DNA, Hershey-Chase confirmed DNA entry in phage infection.

DNA replication is the semi-conservative process by which one DNA molecule produces two identical DNA molecules, each containing one parental strand and one newly synthesized strand.

For replication fork answers, include template strand, primer, DNA polymerase, leading strand, lagging strand, Okazaki fragments, and ligase.

Transcription is the synthesis of RNA from a DNA template strand by RNA polymerase, using a transcription unit made of promoter, structural gene, and terminator regions.

For transcription unit questions, always label promoter upstream, structural gene in the middle, terminator downstream, and identify template versus coding strand.

The genetic code is the set of triplet codons in mRNA that specify amino acids, and translation is the ribosome-mediated synthesis of a polypeptide using mRNA, tRNA, and amino acids.

For translation answers, mention mRNA codon, tRNA anticodon, aminoacylation, ribosome, initiation, elongation, termination, and peptide bond formation.

The lac operon is an inducible gene-regulation system in bacteria where lactose or its isomer acts as an inducer, allowing transcription of genes needed for lactose metabolism.

Draw the operon in order and explain separately what happens in absence and presence of inducer.

The Human Genome Project was an international effort to sequence and map the human genome, while DNA fingerprinting identifies individuals by analyzing variable DNA regions such as VNTRs.

Separate HGP goals from DNA fingerprinting steps. Use terms like VNTR, probe, autoradiogram or banding pattern, and application.