True or false: somatic hypermutation can increase affinity without changing antigen specificity.

Which characteristic best describes all eukaryotic cells? They reproduce by binary fission. They have nuclei with DNA. They lack cellular organelles. They are the simplest organisms.

As people become more concentrated in cities, some pressure on eco-systems in areas that are now less populated eases. Why do you think this is the case

A gene is defined as A gene is defined as a sequence of nucleotides in DNA that codes for a functional product. a sequence of nucleotides in RNA that codes for a functional product. three nucleotides that code for an amino acid.

The very first effect of even a small amount of alcohol on a person's safe driving ability is to reduce his or her:

Listed below are four adaptations of terrestrial vertebrates. Which is a characteristic only of truly terrestrial animals with no need to return to water at any stage of the life cycle? 1. tetrapod locomotion 2. hearts with more than two chambers 3.

Which statement is NOT true of genetic drift? A) genetic drift creates greater diversity within a population B) population bottleneck and founder effect are two types of genetic drift C) the smaller the population, the greater the impact genetic

Which of the following statements about biodiversity is true? a. Changes to biodiversity always positively affect an ecosystem. b. Changes to biodiversity always negatively affect an ecosystem. c.

Which eras ended with a mass extinction? O A. Paleozoic and Precambrian O B. Mesozoic and Paleozoic OC. Mesozoic and Cenozoic O D. Cenozoic and Paleozoic

Why are the maximum winds inside a tornado so high

Which of the following has a strong, positive inotropic effect, meaning it increases the strength of each contraction of the heart?