What benefit do nitrogen-fixing organisms provide in an ecosystem?

a nitrogen atom has 7 protons, and the most common isotope of nitrogen has 7 neutrons. A radioactive isotope has 9 neutrons. What are the atomic numbers and mass numbers of the stable and radioactive forms of nitrogen?

Genetic diversity in Kingdom Plantae?

A vaccine a. can be harmful because it contains pathogens such as viruses. b. contains a changed pathogen, so the pathogen is no longer harmful. c. provokes a response from the viral immune system. d. all of the above

What's test for oil. List at least three and explain. I will mark brainliest.

Why is it significant that pollen contains a multicellular male gametophyte instead of just male gametes? The non-gamete cells of the male gametophyte provide protection from desiccation and UV radiation.

What is true about telomerase?

Lewis is exercising and his muscles need oxygen. Which best describes how systems interact to bring his body into homeostasis? The circulatory system brings oxygen to the respiratory system, which delivers oxygen to the muscular system.

Match the term to its description. Match Term Definition Elliptical galaxy A) Does not have a distinct regular shape Galaxy B) Forms a perfect sphere or an ellipse and is flattened to some degree Irregular galaxy C) Is a collection of several

The outer edge of the nostril is called the

A desert area has many species of cactus and brush as well as birds, snakes, lizards, and rodents. This desert is an example of a what: climax community, pioneer species, disturbance, secondary succession.