Section 24.1 (Exam 1)

Question 1

What did the first split in the tree of life yield?

Answer 1

Bacteria and Archaea

Question 2

Bacterial cell walls contain ________________, a polymer of amino sugars. Archaeal cell walls don’t have this polymer of amino sugars.

Answer 2

peptidoglycan

Question 3

How do antibiotics target bacteria?

Answer 3

Antibiotics interfere with synthesis of peptidoglycan-containing cell walls.

Question 4

Gram-positive bacteria retain which color dye?

Answer 4

violet (crystal violet)

Question 5

Gram-negative bacteria retain which color dye?

Answer 5

red (safranin)

Question 6

This type of bacteria has a thick external layer of peptidoglycan outside of the cell membrane.

Answer 6

Gram-positive bacteria

Question 7

This type of bacteria has a thin layer of peptidoglycan within its periplasmic space, which is encased within an inner and outer membrane.

Answer 7

Gram-negative bacteria

Question 8

Coccus (cocci)

Answer 8

spherical shape

Question 9

Bacillus (bacilli)

Answer 9

rod shape

Question 10

Spirillum (spirilli)

Answer 10

spiral shape

Question 11

Which shapes of bacteria form chains or clusters?

Answer 11

Bacilli and spirilli

Question 12

This type of organism can come in many shapes. Some are cocci, bacilli, triangular, square, and flattened.

Answer 12

Archaea

Question 13

rRNA is present in all ___________.

Answer 13

free-living organisms

Question 14

Why is lateral gene transfer unlikely for rRNA?

Answer 14

Its role is crucial, and lateral gene transfer could lead to potentially harmful mutations.

Question 15

Because rRNA evolves slowly…

Answer 15

It is easy to find similarities in DNA sequences.

Question 16

rRNA is evolutionarily ___________.

Answer 16

ancient