The channels in cell membranes that help substances to move in and out 20 poll of cells during active transport are made of
A. protein.
B. chlorophyll.
C. cytoplasm
D. carbohydrates
NEED ASAP

What initially causes a nerve impulse? release of enzymes out of the neuron movement of chemicals into the dendrites of the neuron pathogens attacking the dendrites of the neuron red blood cells bathing the neuron

Getting out of bed is the first goal i tackle each day. 2several small goals are achieved by me as the day progresses. 3when i am riding the bus home or walking the dog, i think about the bigger goals i have for my life. which statement correctly describes the verb tense, aspect, and voice in this paragraph? a.sentences 1 and 2 contain present progressive verbs. sentence 3 contains both present progressive and simple present verbs. sentence 2 uses passive voice. b.sentences 1 and 2 contain simple present verbs. sentence 3 contains present progressive verbs. all three sentences use active voice. c.sentences 1 and 2 contain present progressive verbs. sentence 3 contains simple present verbs. all three sentences use active voice. d.sentences 1 and 2 contain simple present verbs. sentence 3 contains both present progressive and simple present verbs. sentence 2 uses passive voice.

How does natural selection change thephenotypes within a population over time?