Which of the following statements is not true of nitrogen-fixing bacteria? they provide an important way for biologically available nitrogen to enter ecosystems. they live in root nodules. they are very common in symbioses in all plant families. some are free-living in the soil. they are very common in symbioses with plants from the legume family.

Because of its structure the cell membrane is known as a phospholipid ? a. bilayer b. molecule c. fluid d. barrier

Ry was studying two populations of the same species of lizards. one population lived on an island and the other lived on the mainland. both populations were affected by a hurricane that hit the island and the mainland with equal force. a year later, henry was testing the gene frequency and saw a decrease in genetic variation in the island species, but not in the mainland species. which best describes a conclusion he might have reached? gene flow greatly affects small populations, but large populations can recover. genetic drift greatly affects small populations, but large populations can recover. gene flow greatly affects large populations, but small populations can recover. genetic drift greatly affects large populations, but small populations can recover.

Melting glaciers is a serious threat to the environment what is the possible consequence of melting glaciers on polar bears?