Which of the following is exchanged between two or more atoms that undergo ionic bonding?
a. transitory electrons
b .neutrons
c. electrical charges
d .valence electrons
Ans: d .valence electrons
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Which of the following would be used by a chemoorganotroph for energy?
A) C2H3O2- B) H2 C) CO2 D) H+
If the wild type DNA sequence reads THE CAT ATE THE BIG RAT, what type of mutation would change the sequence to THE CAT ATE (stop)?
A. Insertion B. Silent C. Deletion D. Missense E. Nonsense
G protein-linked receptors are transmembrane proteins that convert an extracellular hormone signal
into an intracellular signal that affects certain cell processes. ____________________ Indicate whether the statement is true or false.
In 1971, Dr Judah Folkman published the "angiogenic hypothesis" suggesting that a tumor cannot grow beyond 1–2 millimeters without the development (angiogenesis) of new blood vessels that provide access to oxygen and nutrients
During the 1990s, it was discovered that vascular endothelial growth factor (VEGF) stimulates the proliferation and migration of the cells that form blood vessels, leading to the formation of new blood vessels. VEGF binds to receptor tyrosine kinases (RTKs) on the cell surface and causes the RTKs to dimerize and become active, thereby initiating an intracellular signaling cascade that stimulates cell division and inhibits apoptosis. Many cancer cells secrete high levels of VEGF. Increased VEGF expression in a tumor is correlated with a poor medical outcome for the patient. Some evidence suggests that blocking VEGF-dependent signaling may prevent the formation of new blood vessels and lead to the death of immature blood vessels without disturbing mature blood vessels. You work for a biotechnology company that seeks to create anticancer drugs that prevent the growth of tumors and/or cause tumors to shrink, while leaving normal cells relatively untouched. After learning about VEGF, you have a bright idea for a new mechanism of action for a potential anticancer drug. What is your idea?