Cells and the cell Cycle

What is the nitrogenous base that pairs with Adenine when an mRNA is made during transcription?

• Uracil

• Guanine

• Cytosine

• Thymine

Motor proteins

• Transport substances within the cell along the cytoskeleton.

• Modify the shape and structure of DNA.

• Produce ATP molecules.

• Generate electrical signals.

Oncogenes are mutated forms of genes. Oncogenes can transform a cell into a tumor cell. Some tumor cells are benign, while others are malignant. How does the presence of an oncogene lead to the formation of a tumor?

• ATP Production is inhibited.

• Cell division is unregulated

• Somatic Cell Growth in size.

• Antibody activity is unregulated.

Which of the following explains why cells that contain the same genetic material do not develop into the same kind of cells?

• Because internal and external stimuli can trigger the activation of specific genes in the DNA of the cell.

• The cell DNA is mutating and creating different cells.

• Cells are expressing the same genes but producing different proteins.

• Cells are activating different enzymes, resulting in different proteins.

Which of these is MOST LIKELY an indication that cells may have become cancerous?

• The cell does not respond to the checkpoints

• The cell divides rapidly

• The cell produces more proteins

• The cell is resistant to antibiotics

A student studying mitosis captures an image of cells from an onion root tip with a camera mounted on a microscope.

Which events occur after the phase circled in the student's image?

• Paired chromosomes separate.

• Chromosomes condense

• Chromosomes replicate

• Cell membrane begins to form around the two daughter cells

What is the optimal temperature for the enzyme illustrated in the graph?

• 47 °C

• 65 °C

• 25 °C

• 35 °C

In animal cells, the spindle fibers that emerge from the centrioles help the chromosomes separate during

• Anaphase

• G1

• S

• Cytokinesis

A diagram of the DNA double helix is provided. Which of the following components of DNA is indicated by the arrow?

• Sugar-phosphate backbone

• RNA

• Histones

• Nucleotides

Passive transport, such as diffusion, facilitated diffusion and osmosis, work as long as there is a __ moving molecules from high concentration to low concentration.

• Concentration gradient

• Temperature gradient

• Pressure gradient

• Electric current