Which of the following gases were present in the atmosphere of 4 billion years ago?

A) water

B) methane

C) ammonia

D) all of the above

Many bivalves, like scallops, live in salt water. The scallop captures food particles from water that flows over its gills. Which of these is the best classification of the scallop? a. a chunk feeder b. a decomposer c. a filter feeder d. a grazer

Explain how the amount of available energy changes as energy moves up a food chain.

A. The variety of organisms within an ecosystem is characteristic of which type of diversity? Genetic diversity b. Ecosystem diversity Species diversity d Regional diversity С.

Based on the above tree, which statement is NOT correct? Group of answer choices Salamanders are a sister group to the group containing lizards, goats, and humans The salamander lineage is a basal taxon Salamanders are as closely related to goats as

What is the mass number of an ion with 109 electrons 159 neutrons and a + 1 charge? Express your answer as an integer

Favorable changes in species get passed down through the generations because of

The most common form of aggression seen in animal hospitals is

What is the term referring to the type of reaction occuring when complex molecules are formed from simpler molecules and water is removed

Which of the following factors does NOT limit population growth? a. species c. space b. carrying capacity d. food

What happens if a mutation is in a gamete