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Flashcards in Chapter 3 Deck (13):
1

What is the basic unit of life?

A cell

2

Why is the cell the smallest example of a living entity?

There is no smaller entity that can meet the criteria for life.
• Is able to reproduce and grow
• Responds to stimuli
• Remains homeostatic
• Takes in and uses materials from the environment
• Adapts to its environment

3

T or F: All living organisms are made up of cells.

True

4

In what units are cells measured?

Micrometers (µm)

5

What is the average diameter of the human cell?

100 micrometers (µm)

6

What is a zygote?

The first cell of a new multicellular organism. It is created when a sperm cell fertilizes an egg cell

7

What are the two broad classifications of cells?

■ Prokaryotes
■ Eukaryotes

8

What is included in the Prokaryotic group?

Two groups of bacteria:
■ Eubacteria
■ Archaebacteria

9

What is included in the Eukaryotic group?

■ Animals
■ Plants
■ Fungi
■ Some single-celled organisms called protists

10

What is a plasma membrane?

An outer membrane that regulates what enters and exits a cell. The membrane is a phospholipid bilayer.

11

Selectively permeable

A plasma membrane of a cell allows only certain molecules to enter the cell.

12

Cytoplasm

A semifluid medium that contains water and various types of molecules suspended or dissolved in the medium. The presence of proteins accounts for the semifluid nature of the cytoplasm. Cytoplasm contains organelles.

13

Organelles

Membranous structures and any well-defined subcellular structure.