Why is the phospholipid bilayer considered semipermeable?
A. The hydrophobic tails act as a barrier to nonpolar molecules.
B. The bilayer is a barrier to some, but not all, substances on either side of it.
C. Large molecules can only pass through the layer of hydrophilic phospholipids.
D. The bilayer is completely nonpolar, which prevents some molecules from passing.
E. Small, nonpolar molecules do not pass through the phospholipid bilayer.
Answer: B. The bilayer is a barrier to some, but not all, substances on either side of it.
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Biomes are broad regional areas with defined flora and fauna. Which one of the following choices correctly identifies the biomes shown plotted in the graph of precipitation versus temperature?
A. Tropical Rain forest = 1; Desert = 2; Tundra = 3; Grassland = 4
B. Tropical Rain forest = 1; Desert = 3; Tundra = 4; Grassland = 2
C. Tropical Rain forest = 3; Desert = 4; Tundra = 1; Grassland = 2
D. Tropical Rain forest = 3; Desert = 1; Tundra = 2; Grassland = 3
Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
Gather Content
· What do you already know about biomes?
Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
In his monohybrid crosses, Mendel deduced that one trait was recessive because that trait was ____
a. not present in the F1 and did not reappear in the F2 b. present in the F1 and in the F2 c. not present in the F1 and reappeared in the F2 d. present only in the parents e. present only in the F2
Group living allows transmission of cultural traits among in wild chimpanzees, such as ________
a. the capacity to make and use simple tools such as sticks to extract termites from a mound b. the strong pair-bond relationships formed between males and females well before sexual maturity c. a crude form of writing where male chimps scratch markings in the dirt d. the tradition of chimps frequently leaving one social group to join another
What is the consequence of methylation of DNA sequences called CpG islands?
A. insulator sequence formation B. transcriptional stalling C. transcription repression D. active transcription E. recruitment of chromosome-remodeling complex