HELPP IMA GIVE YOU 20 PONTS PLI The mass extinction of the dinosaurs, approximately 65.5 million years ago, is inferred by most scientists to have been caused by

A)
a large energy surge from the surface of the Sun

B)
the occurrence of a major ice age

C)
an impact event occurring on Earth's surface

D)
earthquakes occurring along crustal plate boundaries

q: compare the parts of a cell and the cell as a whole to another common nonliving system (i.e., a car, a city,

a:

comparing this to the inside of a food building/company.

all cells are surrounded by a plasma membrane, which protects the cell from its environment, keeping toxic substances out of the cell. it regulates which molecules are allowed to enter and exit the cell.

regulates all cell activity such as cellular metabolism, and growth in addition to storing and maintaining the cell's dna for transcription and replication. determines what proteins to make.

contains the organelles; site of most cell activity

the place where ribosomes do their working activity.

builds the proteins.

prepares proteins for use or export.

responsible for breaking down and absorbing materials taken in by the cell.

maintains cell shape.

transforms one form of energy into another.

who knows

explanation: