44
.
Given that primitive Earth was high in inorganic molecules, but low in oxygen, which of the following organisms would we expect to appear first in the fossil record?
-
archaea
-
fish
-
protists
-
plants
45
.
Why is it challenging to study the biochemistry of bacterial fossils and determine if the fossils are members of the domain archaea, rather than bacteria?
-
Bacteria lack rigid structures, thus make the study of fossils difficult.
-
Bacteria have rigid structures, but their fossil impression is scarce.
-
Fossils of bacteria are rarely found because bacteria were not abundant in the past.
-
A fossil of bacteria changes overtime due to the presence of new bacteria living on them.
46
.
Pictured are two cells along with their radius. What does cell B likely have when compared to cell A?
-
smaller surface area and larger volume
-
larger surface area and smaller volume
-
smaller surface area-to-volume ratio
-
larger surface area-to-volume ratio
47
.
Consider the shapes. The diameter of the sphere is equal to 1mm and the side of the cube is also equal to 1mm. Which has a greater volume? Which has a greater surface area?
-
The cube has the greater volume and greater surface area.
-
The sphere has greater surface area and the cube has the greater volume.
-
The sphere has the greater surface area and greater volume
-
The cube has the greater volume, and they have the same surface area.
48
.
Which of the following is true regarding the surface-to-volume ratios of the cube and the sphere when the diameter of the sphere is equal to the side of the cube?
-
The sphere will have a higher surface area than the cube.
-
The cube will have twice the surface area of the sphere.
-
The sphere will have a higher surface area-to-volume ratio than the cube.
-
The surface area to volume ratios will be equal
-
The sphere will have a lower surface area-to-volume ratio than the cube.
49
.
This figure shows the relative sizes of microbes on a logarithmic scale. What is the major consideration in setting the lower limit of cell size?
-
The cell must be large enough to fight the pathogens
-
The cell must be large enough to attach to a substrate.
-
The lower limit should be small enough, for the cell to move in the fluid efficiently.
-
The cell size must be large enough to fit all the processes and structures to support life.
50
.
Which of the following structures has the same general structure in Archaea, Bacteria, and Eukarya, pointing to a common origin?
-
centriole
-
cytoplasmic membrane
-
Golgi apparatus
-
nucleus
51
.
Why does the structure of the cytoplasmic membrane point to a common ancestor of all life?
-
All living cells use ATP.
-
There is a similar arrangement of phospholipids and proteins in all branches of life.
-
The lipid nature of the membrane makes it the most primitive trait because lipids are the most basic macromolecule.
-
It does not. Archaea broke off first from all other life as evidenced by their lack of a cytoplasmic membrane.
52
.
Which organelles would be present in high numbers in the leg muscles of a marathon runner?
-
centrioles
-
chloroplasts
-
mitochondria
-
peroxisome
53
.
Macrophages ingest and digest many pathogens. Which organelle plays a major role in the activity of macrophages?
-
chloroplast
-
lysosome
-
nucleus
-
peroxisome
54
.
You are looking at a sample under a light microscope and observe a new type of cell. You come to the conclusion that it is a bacterium and not a eukaryotic cell. What would you observe to come to this conclusion?
-
The cell has a cell wall.
-
The cell has a flagellum.
-
The cell does not have a nucleus.
-
The cell has a negative gram stain.
55
.
Thiomargarita namibiensis is a large single cell organism, which can reach lengths of 700μm. The cell is classified as a bacterium. What is the main argument to justify the classification?
-
This organism shows simple diffusion for the uptake of nutrients, and is thus classified as a bacterium.
-
This organism does not show presence of any membranous cell organelles, and thus is classified as a bacterium.
-
The existence of these organisms in long chains and pearl appearance classifies them as bacteria.
-
The organism has chloroplasts but lacks mitochondria, and therefore is classified as a bacterium.
56
.
Radioactive amino acids are fed to a cell in culture for a short amount of time. This is called a pulse. You follow the appearance of radioactive proteins in the cell compartments. In which organelles and in what order does radioactivity appear?
-
endoplasmic reticulum - lysosomes - Golgi body - vesicle - extracellular region
-
endoplasmic reticulum - vesicles - Golgi body - vesicles - extracellular region
-
Golgi Body - vesicles - endoplasmic reticulum - vesicles - extracellular region
-
nucleus - endoplasmic reticulum - Golgi body - vesicle - extracellular region
57
.
With which cellular structure does the extracellular matrix interact?
-
cytoskeleton
-
nucleus
-
smooth endoplasmic reticulum
58
.
Which structure or structures allow bacteria to move about?
-
fimbriae only
-
flagella only
-
flagella and fimbriae
-
plasmid and capsule
59
.
Cells lining the intestine absorb a lot of nutrients. How did those cells adapt to their function?
-
Cells use cilia to move nutrients to their surface.
-
Cells grow much larger than adjacent cells to increase intake
-
Cells are flat and thin to absorb more nutrients.
-
Membrane folds called microvilli increase the surface area.