1. A cardiac muscle cell has approximately 5,000 mitochondria, while an epithelial cell has approximately 1,000 mitochondria. What is the reason for the difference in the number of mitochondria?
А.
The cardiac muscle cell contracts nonstop, requiring more energy.
С.
B. The cardiac muscle cell acts as a barrier to protect the organism, requiring more energy.
The cardiac muscle cell is responsible for multiple functions, requiring more energy.
D. The cardiac muscle cell attaches to other cells to line body surfaces, requiring more energy.
2. The maturation of red blood cells takes place in the bone marrow over the course of three weeks. During this time, the cells lose their nuclei in a process known as enucleation.
What benefit does the lack of nuclei provide for red blood cells?
A. It leaves more space for the molecule responsible for carrying oxygen.
B. It allows the red blood cells to contain more DNA than other cell types.
C.
D.
It allows the red blood cells to create new DNA that is unique for each blood cell.
It leaves more space for mitochondria that are needed for the active transport of materials.
3. A researcher analyzes two different cell samples, A and B, by first using a mild detergent to rupture the cell membrane in each sample and release the contents of the cells. Next, the researcher uses a centrifuge to spin and separate the contents of each sample by density, then records and analyzes the results in a data table.
Contents of Cells nuclear materials mitochondria chloroplasts
cytoplasm
Percentage in Sample A
30
24
0
46
Percentage in Sample B
22
25
28
25
What can be interpreted from an analysis of the data about Sample A and Sample B?
A. Sample A contains plant cells, and Sample B contains animal cells.
B. Sample A contains animal cells, and Sample B contains plant cells.
C. Sample A contains bacterial cells, and Sample B contains plant cells.
Sample A contains animal cells, and Sample B contains bacterial cells