What problem may have caused the vikings to stop coming to north america?
a) battles with native americans
b) lack of food
c) inability to build houses
d) bad weather

Which of the following are causes of coastal erosion? check all that apply. beach grasses and other plants trap windblown sand. wave action carves away the coastline. groundwater under pressure is forced to earth’s surface. artificial structures stop the natural flow of sand along the coast. underground caves collapse as bedrock is dissolved.

How do chloroplasts set plants apart from other living things

You have just sequenced a new protein found in mice and observe that sulfur-containing cysteine residues occur at regular intervals. what is the significance of this finding? it will be important to include cysteine in the diet of the mice. cysteine residues are required for the formation of α helices and β pleated sheets. cysteine residues are involved in disulfide bridges that form tertiary structure. cysteine causes bends, or angles, to occur in the tertiary structure of proteins.