Which partly explains why the domestication of animals tended to increase the human food supply?
[a] domesticated animals provided food and labor for cultivation.
[b] domesticated animals were playful companions.
[c] the fur, skin, and feathers of domesticated animals could be used for trade.
[d] domesticated animals had to be fed as well.

Dr. bad has developed a way to damage the atp-binding cassette transporter (abc transporter) on a cell. the cell's abc transporter can no longer bind and use atp when it's transporting substances. which of the following statements best describes how this damage would effect the transport of substances in the affected cell? (choice a) substances at a low concentration outside the cell would be more rapidly transported into the cell, where there is a high concentration. (choice b) substances at a high concentration outside the cell would not be transported into the cell, where there is a low concentration. (choice c) equilibrium would be established between all substances inside and outside of the cell. (choice d) substances at a low concentration outside the cell would not be transported into the cell, where there is a high concentration.

Aresearcher has developed two stains for use with seed plants. one stains sporophyte tissue blue; the other stains gametophyte tissue red. if the researcher exposes pollen grains to both stains, and then rinses away the excess stain, what should occur? a) the pollen grains will be pure red. b) the pollen grains will be pure blue. c) the pollen grains will have red interiors and blue exteriors. d) the pollen grains will have blue interiors and red exteriors.

Which are characteristics of flukes? check all that apply. a they are free living. b they are a type of flatworm. c they reproduce sexually. d they have eyespots. e they are segmented.