Select the elements that have 4 valence electrons. hydrogen (H)

krypton (Kr)

strontium (Sr)

carbon (C)

oxygen (O)

tin (Sn)

List two new traits (structural or behavioral) that each new species of rat might demonstrate as it adapts to the conditions on two of the four islands. choose only two islands that are described in the lesson. record the island latter and the major habitat feature of the island. then list two new traits each rat subspecies might demonstrate in order to survive the habitat on that island. note: new traits should be unique to that island and be in response to that island’s habitat feature. i cannot remember islands that were names in the lesson so only answer if you have done the lesson (5.13 life science 7b) choose 2 of the islands and describe a structural and a behavioral trait for a rat on each island so 4 total answers, 2 different structurals and 2 different behaviorals, one for each rat for each island

How do tides affect the organisms living in intertidal zones? a. no organisms live in intertidal zones due to the tumultuous environment. b. the mechanical forces of the waves keeps the organisms clean. c. only plants live in intertidal zones because the animals float away with the waves and never return. d. the mechanical forces of the waves can dislodge the organisms from their habitat.

Giraffes with short necks tend to be unable to access enough food, while giraffes with long necks can reach more food at the tops of trees. this causes an advantage for giraffes with long necks. how would you explain this? a. this is an example of a stabilizing selection in which the intermediate form of a trait is advantageous compared to the extreme forms of the trait. b. this is an example of a disruptive selection in which the population of cacti is divided and well-defined. c. this is an example of directional selection in which one end of the bell curve is better adapted to its environment than the other end. d. this is an example of bidirectional selection in which evolutionary pressures from multiple sources encourage an organism to adapt