A scientist is studying an organism and has classified it as an animal. Which statement must be true about the organism?

A) It is multicellular.

B) It displays radial symmetry.

C) It has a backbone.

D) It contains cells without nuclei.

Lesions that are a different color than the color of the skin are which type?

What's the difference between alleles that are codominant and those that are incompletely dominant?

Why would individuals with hiv possibly contract a pneumonia infection that is rare in the rest of the population

Which of the following is not a freshwater ecosystem? a. lakes b. rivers c. seas d. springs

Which of the following scenarios would be least likely to result in a fossil?

In what ways are index fossils and layers of volcanic ash found in ice cores similar?

The percentage of silt in silty clay loam is what? a. 60% to 70% b. 80% to 90% c. 90% to 100% d. 10% to 20%

Which of the following would cause an error in DNA replication? A. DNA ligase taking apart chunks of DNA B. Helicase making a replication fork C. DNA polymerase pairing new Cs with Gs D. DNA polymerase checking the DNA

Which of the following about Dalton's theory of matter is true? A Atoms of the same element have the same mass. B Compounds formed from two elements will not always have the same proportions. C Atoms cannot be divided into smaller parts.

What would cause a particular polygenic trait, like tall stature in humans, to become more frequent in a population over time?