In which situations is the principle of cross-cutting relationships useful in determining relative age? Select three options.

A fault breaks through sedimentary layers.
The formation of an intrusion in the Earth’s surface.
Igneous rock forms between sedimentary layers.
Sedimentary layers form over millions of years in a lake bottom.
Lava flows form on top of one another from several eruptions over time.

Which best describes an adaptation that could be found in a fish that lives in a slow-flowing stream? the ability to attract prey by glowingextra gills, for oxygen extractionthe ability to grow largerextra fat, for warmth

What is an endocrine function? (apex) a.esophageal glands release mucus into the esophagus b.salivary glands release saliva into mouth c.swear glands release sweat to the skin d.the pineal gland releases melatonin into the bloodstream

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?