DAT PAT flashcards

30 cards. Read the term and the definition here. The deck at the top of this page is optional.

Hardy-Weinberg allele equation

For a locus with two alleles, p + q = 1, where p and q are allele frequencies. Genotype frequencies follow p² + 2pq + q² = 1 under no mutation, migration, selection, or drift with random mating.

Km and enzyme affinity

Km is the substrate concentration giving half of Vmax. A low Km means the enzyme reaches half-maximal velocity at low substrate, indicating high affinity for substrate.

Semiconservative replication

Each new DNA double helix contains one original parental strand and one newly synthesized strand. DNA polymerase adds nucleotides only to a 3' end, so strands grow 5' to 3'.

Dihybrid cross ratio

Crossing two individuals heterozygous at two independently assorting loci produces a 9:3:3:1 phenotypic ratio in offspring, assuming complete dominance at both loci.

Cellular osmosis direction

Water diffuses across a semipermeable membrane from lower solute concentration to higher solute concentration. Animal cells shrink in hypertonic solutions; plant cells plasmolyze as the membrane pulls from the wall.

ATP yield per glucose

Aerobic respiration of one glucose yields about 2 net ATP from glycolysis, 2 from the citric acid cycle, and roughly 26 to 28 from oxidative phosphorylation, totaling about 30 to 32.

Hemoglobin oxygen dissociation curve

The sigmoidal curve reflects cooperative binding: oxygen affinity rises as more O2 binds. Rightward shifts (higher CO2, lower pH, higher temperature) release oxygen more readily to tissues.

Newton's second law

Net force equals mass times acceleration, F = ma. Acceleration is proportional to net force and inversely proportional to mass, and points in the direction of the net force.

Angle ranking strategy

Judge the size of the opening between the two rays, not the length of the drawn lines. Short line segments make angles look larger, so mentally extend both rays before comparing.

Cube counting rule

Count every exposed face, including faces on the bottom of cubes that overhang edges or rest on the ground. Tally face by face across the whole structure to avoid double counting.

Paper folding hole count

Each punch through n layers creates n holes. Unfold step by step in reverse order, reflecting each hole across the crease line of the fold that covered it.

Hole on a fold line

A punch centered exactly on a crease produces a single merged hole when unfolded, because the reflected copy coincides with the original rather than forming a separate hole.

Aperture passing test

A solid figure passes through an opening only if its cross-section fits at every depth. Compare the widest cross-section of the solid with the narrowest part of the aperture.

Hidden edges in views

In top, front, and end views, edges not directly visible are drawn as dashed lines. Every feature in one view must align with its projected position in the other two views.

Cube opposite faces

On a cube net, faces separated by exactly one face in a straight row become opposite faces. Opposite faces never share an edge and cannot appear adjacent on the assembled cube.

Main idea question

The correct answer states the passage's central claim and covers the whole passage. Choices that are accurate but limited to one detail do not capture the main idea.

Tone answer trap

Extreme qualifiers such as always, never, or completely usually misrepresent an author's measured tone. Match the intensity of the answer to the actual language used in the passage.

Valid inference standard

An inference must follow necessarily from stated evidence. Answers that are merely plausible, or that require outside knowledge or unstated assumptions, are incorrect even if true.

EXCEPT question method

Three choices are directly supported by the passage and one is not. Verify each choice against a specific line, then select the single unsupported statement.

Vocabulary in context

Substitute each answer choice into the original sentence and keep the option that preserves the passage's meaning. The most common dictionary definition is often wrong.

Function of a paragraph

Structure questions ask what a paragraph does, such as giving an example, raising a counterargument, or conceding a point, not merely what topic it discusses.

Narrow scope preference

When two answers seem correct, choose the one with narrower scope and direct textual support. Reject the choice that depends on an assumption the passage never states.

Successive percent change

Percent changes multiply as factors rather than adding. A 20 percent increase followed by a 20 percent decrease gives 1.2 times 0.8, or 0.96, a net 4 percent decrease.

Weighted average

Multiply each group mean by its count, sum the products, and divide by the total count. The combined mean always lies between the two original group means.

Probability addition rule

For overlapping events, P(A or B) equals P(A) plus P(B) minus P(A and B). For mutually exclusive events the intersection is zero, so probabilities simply add.

Combinations versus permutations

Combinations nCr = n!/(r!(n−r)!) ignore order and suit committee or handshake problems. Permutations nPr = n!/(n−r)! count arrangements where order matters, such as rankings.

Perpendicular slope rule

Two nonvertical lines are perpendicular when their slopes are negative reciprocals, so the product of the slopes equals negative one. Parallel lines have equal slopes.

Average speed round trip

For equal distances traveled at speeds a and b, average speed is the harmonic mean 2ab/(a + b). Averaging the two speeds arithmetically overstates the true average.

Scaling of area and volume

If all linear dimensions scale by factor k, surface area scales by k squared and volume by k cubed. Doubling a cube's edge multiplies volume by eight.

Logarithm product rule

The log of a product equals the sum of the logs, and the log of a power equals the exponent times the log. Change of base: log base b of x equals ln x divided by ln b.