Biology  5/e   Raven/Johnson
	Student   Online Learning Center

Nature of scientific experiments: The scientific method is the formulation of hypotheses based on a systematic collection of data and the experimental testing of the hypotheses. The process is not mechanical, but involves creative insight and critical thinking.

Structure of DNA: DNA is a complex molecule coding for amino acid sequences in proteins with triplets of nucleotides in the DNA.

Nucleotides: A nucleotide is a segment of a nucleic acid. A nucleotide is composed of a five-carbon sugar, a phosphate group, and an organic nitrogen-containing base.

Structure of proteins: A protein is a long polymer chain of amino acid subunits linked end to end.

The structure of chromosomes: A chromosome is a single, long, double stranded DNA fiber that is often coiled to occupy less space. The typical chromosome contains about 60% protein and 40% DNA. Somewhere on the chromosome is a constriction called the centromere.

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