Which macromolecule did the majority of scientists favor as the "first" to be found in protobionts?
A. DNA.
B. RNA.
C. Amino acids.
D. Proteins.
B. RNA.
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The scientific work that established DNA, rather than protein, as the molecule of heredity was performed prior to
A) Mendel's work on heredity. B) the elucidation of the double helix structure of DNA. C) Antonie van Leeuwenhoek's observation of internal cell structures. D) the description of the enzymatic steps of glycolysis. E) the formation of the chromosome theory of heredity.
The first human genetic disease to be successfully treated by gene therapy was ________
A) cystic fibrosis B) sickle cell anemia C) chronic myelogenous leukemia D) adenosine deaminase deficiency E) albinism
What is the mechanism by which binding of testosterone to the testosterone receptor leads to upregulated gene transcription?
A. Binding of testosterone to the testosterone receptor leads to the activation of a G protein that stimulates the activation of enzymes that promote gene transcription. B. Binding of testosterone to the testosterone receptor leads to the opening of an ion channel that leads to an increase in calcium in the cytoplasm. The increased calcium levels activate calmodulin, which can go on to activate other proteins that promote gene transcription. C. Binding of testosterone to the testosterone receptor leads to the increase in second messengers that activate a kinase cascade, ultimately leading to the activation of transcription factors that promote gene transcription. D. Binding of testosterone to the testosterone receptor activates guanylyl cyclase, and the resulting cGMP promotes gene transcription. E. Binding of testosterone to the testosterone receptor leads to a conformational change that allows the receptor to enter the nucleus where it can bind to DNA and promote gene transcription.
Ecological efficiency is usually higher in aquatic ecosystems than on land, in part because photosynthetic protists do not make ____, as most land plants do.
A. chlorophyll B. ATP C. lignin D. cellulose E. organic material