DAT Exam Questions & Answers 2026 (11–20)

✓ Correct answer: E. Slower

While succession is a relatively fast process, evolution is a much slower one.<br/><br/><b>Key Takeaway: </b>In general, succession is a much faster process than evolution. While succession proceeds in a relatively ordered fashion, evolution is depended on random changes. Succession does proceed until a fixed point, whereas evolution is constantly taking place.

✓ Correct answer: D. ribosome.

Ribosomes produce proteins in both prokaryotes and eukaryotes.<br/><br/>Choice A is incorrect because prokaryotes do not have Golgi bodies—they lack membrane-bound organelles.<br/><br/>Choice B is incorrect because the nucleoid is not the site of protein synthesis in prokaryotes.<br/><br/>Choice C is incorrect because prokaryotes do not have nuclei.<br/><br/>Choice D is incorrect because the plasma membrane is not the site of protein synthesis in prokaryotes; the ribosome is.

✓ Correct answer: C. These plants have a mutualistic relationship with nitrogen-fixing bacteria

Legume plants are able to live in nitrogen-poor soil because they obtain nitrogen from nitrogen-fixing bacteria. These plants cannot make their own proteins without nitrogen from nitrogen-fixing bacteria.

✓ Correct answer: E. A

Adenine (A) and uracil pair up in RNA.<br/><br/>Choices B and C are incorrect because C (cytosine) and G (guanine) pair up in DNA and RNA.<br/><br/>Choice D (T; thymine) is incorrect because T is found only in DNA and does not pair up with U.<br/><br/>Choice E is incorrect because U (uracil) is not complementary with itself.

✓ Correct answer: C. milfoil evolved from North American plant species

Because its evolutionary history is elsewhere, milfoil has adapted to an environment that lacks the natural predators and pathogens of North America, making it less susceptible to them and therefore more competitive than native plants in North America.

✓ Correct answer: A. all individuals are potential partners for breeding.

A panmictic population is one where all individuals are potential partners. This assumes that there are no mating restrictions, neither genetic nor behavioral, upon the population, and that therefore all recombination is possible. The Wahlund effect assumes that the overall population is panmictic.<br/><br/>A panmictic population is one where all individuals are potential partners. This assumes that there are no mating restrictions, neither genetic nor behavioral, upon the population, and that therefore all recombination is possible. The Wahlund effect assumes that the overall population is panmictic.<br/>In genetics, random mating involves the mating of individuals regardless of any physical, genetic, or social preference. In other words, the mating between two organisms is not influenced by any environmental, hereditary, or social interaction. Hence, potential mates have an equal chance of being selected. Random mating is a factor assumed in the Hardy-Weinberg principle and is distinct from lack of natural selection: in viability selection, for instance, selection occurs before mating.<br/><br/>In a panmictic species, all of the individuals of a single species are potential partners, and the species gives no mating restrictions throughout the population. Panmixia can also be referred to as random mating, referring to a population that randomly chooses their mate, rather than sorting between the adults of the population.<br/><br/>Panmixia allows for species to reach genetic diversity through gene flow more efficiently than monandry species. However, outside population factors, like drought and limited food sources, can affect the way any species will mate. When scientists examine species mating to understand their mating style, they look at factors like genetic markers, genetic differentiation, and gene pool.<br/><br/><img src="asset:assets/questions/a2ef9defaa4e2719.png"/>

✓ Correct answer: D. Y-linked traits can only be inherited from the father.

The statement that is true about sex-linked traits is that Y-linked traits can only be inherited from the father. Since the father is the only parent with a copy of the Y-chromosome, only he can pass that trait on to offspring.<br/><br/><b>Key Takeaway: </b>Sex linkage is the phenotypic expression of an allele (i.e. trait) that is related to the chromosomal sex of an individual. Sex-linked traits are not equally inherited by the sexes, which is the opposite of autosomal traits. In humans, X-linked traits are more common, as the X-chromosome is bigger and has more genes. X-linked traits can be inherited from either parent and inherited by offspring of either sex, but Y-linked traits are only inherited from the father and can only be inherited by males.

✓ Correct answer: B. ATP and NADPH

The light reactions of photosynthesis convert solar energy to usable energy in the form of ATP (choices C and E are eliminated) and NADPH (a reduced electron carrier). The ATP and NADPH (i.e., energy) produced during these reactions are used later during the Calvin cycle to fix carbon dioxide into carbohydrates, like glucose. Because glucose is a product of the light-independent reactions, choice B could be eliminated. Remember that NADPH belongs with photosynthesis to eliminate choice D.

✓ Correct answer: A. active site

The other choices do not describe substrate binding sites on an enzyme.

✓ Correct answer: E. glucose; pyruvic acid

Glycolysis is the first step of respiration, converting a glucose molecule into two pyruvic acid molecules.<br/><br/>Choices A and B are incorrect because acetyl CoA is the molecule that enters the Krebs cycle during aerobic respiration.<br/><br/>Choice D is incorrect because pyruvic acid is the product, not the input, for glycolysis, and glucose is the input, not the product.<br/><br/>Choice E is incorrect because pyruvic acid is converted to acetyl CoA during the linking reaction between glycolysis and the Krebs cycle, though not in a 2:1 ratio.