1.1. Cells Are The Basic Unit Of Life

Question 1

Define cell

Answer 1

The basic unit for all living organisms; it is surrounded by cell surface membrane and contains genetic material (DNA) and cytoplasm containing organelles

Question 2

Define organelle

Answer 2

A functionally and structurally distinct
part of a cell.

Question 3

All cells come from

Answer 3

Pre-existing cells by the process of cell division

Question 4

Define nucleus

Answer 4

A relatively large organelle found in eukaryotic cells, but absent from prokaryotic cells. The nucleus contains cell’s DNA and therefore controls the activities of the cells.

Question 5

What are the two fundamentally different types of cells?

Answer 5

Prokaryotic cells and eukaryotic cells

Question 6

Describe prokaryotic cells

Answer 6

These cells are simpler with the DNA, not surrounded by any membranes, but free in the cytoplasm. They also don’t have any membrane bound organelles.

Question 7

Describe eukaryotic cells

Answer 7

These cells are much larger and more complex and contain a nucleus surrounded by two membranes. The genetic material DNA is in the nucleus. They also have membrane bound organelles.

Question 8

Eukaryotes are said to have evolved from prokaryotes ___________ years ago

Answer 8

More than 2 billion

Question 9

Define eukaryotes

Answer 9

An organism whose cells contain a nucleus and other membrane bound organelles

Question 10

Define prokaryotes

Answer 10

An organism whose cells do not contain a nucleus or other membrane bound organelles

Question 11

Prokaryotes include

Answer 11

Bacteria

Question 12

Eukaryotes include

Answer 12

Animals, plants, fungi and some other organisms.

Question 13

A cell can be thought of as a bag in which

Answer 13

the chemistry of life takes place

Question 14

The membrane is an essential feature of the cell because

Answer 14

It controls the exchange between cell and it’s environment

Question 15

How does the cell surface membrane control the exchange between a cell and it’s environment

Answer 15

By acting as a barrier and controlling the movement of materials across the membrane in both directions.
The membrane is therefore partially permeable.

Question 16

If the membrane were freely permeable, then why couldn’t life exist

Answer 16

Because the chemicals of the cell would simply mix with the surrounding chemicals by diffusion and inside of the cell would be the same as outside the cell. This means some vital conditions for reactions to take place such as a specific concentration of the solution and pH will not be present due the mixing of the chemicals from outside the cell with the chemicals from inside the cell.