Biology: Protein Synthesis and The Cell Cycle

Cancer affects

• Humans only

• Unicellular organisms only

• Multicellular organisms only

• Unicellular and multicellular organisms

Cyclins carefully control the timing of the _______

What are the phases phases of the cell cycle and what happens in each?

Answer explanation

Interphase:

G1 - the cell grows

S- DNA replicates

G2 - cell prepares to divide/prepares for mitosis

M phase: consists of mitosis and cytokinesis

Mitosis = division of the nucleus (4 phases: prophase, metaphase, anaphase, telophase)

Cytokinesis= division of the cytoplasm

Cancer cells differ from normal cells in their _______.

What part of the harmless was transformed in Griffith's experiment?

Answer explanation

Griffith performed an experiment in which he learned that harmless bacteria could be transformed when mixed together. He called the transforming factor a gene. We now know that genes are made of DNA.

How does the ratio of surface area to volume relate to cell growth and division?

Answer explanation

As cells grow bigger, their surface area to volume ratio decreases. This makes it harder for them to transport materials. Eventually when cells grow large enough, they have such difficulty moving materials in/out of the cell that they start to divide.

How does the lac repressor turn OFF the expression of the lac genes?

• Binding to the promoter

• DNA polymerase

• Binding to the operator

• Binding to the lac genes

What does the lac operon control?

• The breakdown of glucose

• The production of glucose

• The breakdown of lactose

• The production of lactose

Explain the central dogma of molecular biology.

Answer explanation

DNA is made into mRNA in a process called transcription. This happens in the nucleus.

mRNA is made into protein in a process called translation. This happens on the ribosome.

How many copies of DNA remain after replication?

• 11

• 2

• 3

• 4