Video Notes: Graphing and Structure of DNA (Biology 150)

Practice flashcards covering graphing concepts (axes, data types, and graph choices) and the structure and properties of DNA (primary/secondary structure, nucleotides, base pairing, and historical discoveries) derived from the lecture notes.

List the graph types mentioned in the notes on Page 1.

Bar chart, histogram, scatter plot, line chart, boxplot, and pie chart.

In graphing data, what does the X-axis (independent variable) represent?

The variable being tested or controlled—the input.

Which data type is typically graphed with a line graph or scatter plot?

Continuous data.

Which graph type is used for percentages of a whole (though uncommon)?

Pie chart.

Which graph types are appropriate for categorical data?

Bar graph or box & whisker.

Define the primary structure of DNA.

A directional sugar-phosphate backbone; nucleotides linked by phosphodiester bonds with 5' and 3' ends.

What is the secondary structure of DNA?

Antiparallel double helix.

State the base pairing rule for DNA and which bases pair.

Purines pair with pyrimidines; A pairs with T (or U in RNA) and G pairs with C.

What holds the base pairs together in DNA?

Hydrogen bonds.

State Chargaff's rule.

%A = %T and %C = %G in double-stranded DNA.

What did Hershey & Chase determine about genetic material?

Genetic material is nucleic acids.

What are the sugar components of DNA vs RNA?

DNA contains deoxyribose; RNA contains ribose.

What are the three components of a nucleotide?

Phosphate group, five-carbon sugar, and nitrogenous base.

What bond links nucleotides to form the DNA backbone?

Phosphodiester bond.

Where are chromosomes located in eukaryotic vs prokaryotic cells?

Eukaryotes: in the nucleus; Prokaryotes: in the cytoplasm (no nucleus).

Why is DNA an effective storage molecule?

It is stable over long periods, can be accurately replicated into new cells and gametes, and can evolve.

What is the relationship between nucleotides and DNA as a polymer?

DNA is a polymer made of nucleotides; nucleotides are the monomers.

Name the two main types of nucleic acids and how their sugars differ.

DNA with deoxyribose; RNA with ribose.

Where does the nitrogenous base attach on the sugar in a nucleotide?

To the 1' carbon of the sugar.

Where does the phosphate group attach on the sugar in a nucleotide's backbone?

To the 5' carbon of the sugar.

What does the 5' to 3' directionality signify in DNA's backbone?

Direction of growth and connectivity; the 5' end carries the phosphate and the 3' end has a free hydroxyl group.

What term describes two DNA strands running in opposite directions?

Antiparallel.

Which scientists contributed to understanding DNA structure?

Maurice Wilkins, Rosalind Franklin, Francis Crick, and James Watson.

What is the observed width and key features of the DNA double helix from X-ray crystallography?

Double helix shape with a sugar-phosphate backbone; bases arranged inside roughly 2.0 nm wide.

What is the role of base pairing in DNA regarding nucleotide composition in the two strands?

In a double-stranded DNA sample, %A = %T and %C = %G.