Slide 1
DNA carries information in its base sequence
Deoxyribonucleic acid, or DNA, carries genetic information in the order of four kinds of bases. The sequence matters as well as the molecule’s chemical composition.
More to Read
DNA is the usual abbreviation. Two DNA molecules can contain the same total numbers of each base yet have different sequences. Like rearranging letters, changing order can alter information without changing the inventory of building blocks.
Slide 2
The two strands use complementary base pairs
In the usual DNA double helix, adenine pairs with thymine and cytosine pairs with guanine. The strands have complementary sequences.
More to Read
Their sugar-phosphate backbones run in opposite directions. This antiparallel arrangement matters to enzymes that copy or read DNA, because those enzymes work with a defined molecular direction.
Slide 3
Genes can produce functional RNA or protein
A gene is a DNA region used to produce functional ribonucleic acid (RNA) or a protein product. Not every stretch of DNA is a protein recipe.
More to Read
Regulatory regions influence when and where genes are used. Other sequences contribute to chromosome structure or have roles still being investigated, so the genome cannot be reduced to a list of protein-coding segments.
Slide 4
Chromosomes package DNA and help control access
DNA is organized into chromosomes rather than left as a loose unreadable tangle. In eukaryotes, organisms whose cells have nuclei, proteins help package it and regulate access.
More to Read
Histone proteins form structures around which DNA wraps. Changes in packaging can influence which regions are accessible to molecular machinery, linking physical organization with gene regulation.
Slide 5
A sequence influences traits through its cellular setting
DNA influences biological function through interactions with cellular machinery and environment. Reading a sequence alone does not reveal every resulting trait.
More to Read
Many traits involve numerous genes and developmental processes. Even a known sequence change may have different effects in different contexts, so predicting phenotype requires more than locating a difference in letters.
Sources
- Deoxyribonucleic Acid DNA
National Human Genome Research Institute
- Gene Expression
National Human Genome Research Institute