Answer:
complement is a system of plasma protiens that can be activated directly by pathogens
2. The endosymbiotic theory suggests that a eukaryotic cell is the result of one prokaryotic cell eating another.
Answer:
Bacteria play a central role
Explanation:
Nitrogen-fixing bacteria, which convert atmospheric nitrogen to nitrates. Bacteria of decay, which convert decaying nitrogen waste to ammonia. Nitrifying bacteria, which convert ammonia to nitrates/nitrites.
<span>blood, lungs and blood vessels that make up the circulatory system.
... The network of veins, arteries and blood vessels transports
oxygenated blood from the heart, delivers oxygen and nutrients to the
body's cells and then returns deoxygenated blood back to the heart</span>
Answers:
A(n) operon is a stretch of DNA consisting of an operator, a promoter, and genes for a related set of proteins, usually making up an entire metabolic pathway.
The Gene of an operon is arranged sequentially after the promoter
A(n) promoter is a specific nucleotide sequence in DNA that binds RNA polymerase, positioning it to start transcribing RNA at the appropriate place.
A(n) regulatory gene codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes.
Regulatory proteins bind to the operator to control expression of the operon.
A(n) repressor is a protein that inhibits gene transcription. In prokaryotes, this protein binds to the DNA in or near the promoter.
A(n) inducer is a specific small molecule that binds to a bacterial regulatory protein and changes its shape so that it cannot bind to an operator, thus switching an operon on.
