The central dogma describes the flow of genetic information: DNA → RNA → Protein.

Indirectly; DNA is first transcribed into mRNA, which is then translated into protein.

Messenger RNA, a transcript of DNA that carries coding information to ribosomes.

RNA polymerase reads the DNA template strand and synthesizes a complementary RNA molecule.

Ribosomes read the mRNA sequence and assemble amino acids into a polypeptide chain.

The genetic makeup of an organism; the set of alleles it carries.

The observable traits or characteristics of an organism, resulting from genotype and environment.

The combination of alleles at a gene locus defines an organism’s genotype.

Dominant or recessive expression of alleles determines the phenotype.

Three bases (a codon) code for one amino acid.

Reverse transcription (RNA → DNA) as in HIV, RNA viruses, and certain noncoding RNAs with regulatory functions.

HIV converts its RNA genome back into DNA to integrate into the host genome.

tRNA, rRNA, and other noncoding RNAs.

20 unique amino acids; codon redundancy allows 64 possible codons.

A, U, G, C; Uracil (U) replaces Thymine (T) found in DNA; sugar is ribose vs deoxyribose in DNA.

Multiple codons can code for the same amino acid.

A sequence of three mRNA nucleotides that specifies one amino acid.

Start codon: AUG, codes for Methionine.

Stop codons: UAA, UAG, UGA; signal termination of translation.

1. Triplet codons
2. Redundant/degenerate
3. Universal (mostly)
4. Non-overlapping

DNA template is transcribed to mRNA (T→U), then read in codons to synthesize corresponding amino acids via tRNA at the ribosome.

Mutations are changes in DNA sequence, can arise from errors in replication, chemicals, or radiation, and create genetic diversity.

Point mutation: single nucleotide change; Chromosome-level: large-scale changes in structure or number of chromosomes.

A nucleotide is replaced by another, may change amino acid coded.

Mutation that does not change the amino acid sequence.

Most are neutral or deleterious; few are beneficial.

Structural (inversion, translocation) and numerical (polyploidy, aneuploidy).

Polyploidy: extra full sets of chromosomes.
Aneuploidy: extra/missing individual chromosomes.
Inversion: segment of chromosome reversed.
Translocation: segment moved to a different chromosome.