True, though the Hadean period is one exception.
Answer:
Which of the following mechanisms is used by gram-negative bacteria to cross the blood-brain barrier? D) Inducing TNF
Explanation:
The blood brain barrier is a barrier formed by brain microvascular endothelial cells, astrocytes and pericytes. Pathogens can cross this barrier by using different mechanisms. The Tumor Necrosis Factor (TNF) is the way gram-negative bacteria cross this mentioned blood-brain barrier.
Phospholipids are typically made up of two fatty acids,a glycerol molecule and a phosphate group that is modified by an alcohol.The phosphate group is negatively charged, it is hydrophilic and it is describes as the polar HEAD of the phospholipid. The fatty acid chains have no charge [neutral], they are hydophobic and they are describe as the non-polar TAIL of the phospholipid.
Option C. the larger A pairs with the smaller T, and the larger G pairs with the smaller C.