<span>Natural selection is when species learn to adapt to
their environment. They could (1) differential reproduction, that is, not all
organisms are able to reproduce to their fullest capacity because nature cannot
simply sustain it and (2) acquire genes, that is heredity. Certain
characteristics of organisms tend to survive if it continues to strive. If it
survives, this trait is passed down to the next generations forgetting the
other traits but only the one who could survive the environment. Therefore it
is true that <span>natural
selection is when ‘organisms inherit advantageous traits, and tend to reproduce
more successfully than other organisms’. One best example is the extinction of
other animals and some with the same species retains.</span></span>
DNA polymerase is an enzyme with a specific active site complementary to the 3' OH end of the DNA strand in terms of charge, size, orientation and shape thus can only bind to 3' end and cannot bind to 5' end for replication to occur
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.
Hypothalamus is a part of the brain that links the nervous system to the endocrine system via the pituitary gland. It helps maintain the internal environment constant by regulating major processes in the body such as the heart rate and the body temperature. It is therefore, both a neural and endocrine organ.
