Cell Growth, Division, and Reproduction

Multiple Select

Which of the following limit cell size? Select all of the answers that apply.

• ratio of surface area to volume

• rate of moving materials across the cell's membrane

• efficiency of using the information in a cell's DNA

• efficiency of DNA replication and cell division

Multiple Select

Why are cells generally so small? Select all of the answers that apply.

• Moving nutrients across their cell membranes is more efficient.

• As they grow, their surface area increases faster than their volume.

• As they grow, their volume increases faster than their surface area.

• Moving waste materials across their cell membranes is more efficient.

Multiple Choice

Which describes sexual reproduction, and not asexual reproduction?

• produces offspring that are genetically identical to a single parent

• produces offspring that inherit half of their genetic information from each parent

• ensures all members of a population have equal fitness in their environment

• can occur very quickly, allowing a population to expand into new territory

Multiple Choice

Hydras may reproduce by budding. In this process, a small polyp forms on an adult hydra, and then it leaves to become a new organism. Which observation would support the conclusion that budding is an example of asexual reproduction?

• The polyp that buds off the hydra has different DNA from the parent.

• The polyp that buds off the hydra is significantly smaller than its parent.

• Budding may occur in a hydra that has been completely isolated from others of its kind.

• Budding may occur in a hydra that has been raised with many others of its kind.

Multiple Choice

Which of these events happens immediately before cell division occurs?

• The cell's genetic material is copied.

• The cell's surface-area-to-volume ratio increases.

• The cell's volume decreases more than its surface area.

• The cell's DNA is distributed evenly throughout the cell.

Multiple Choice

What advantage do chromosomes provide the cell?

• They ensure equal division of genetic material when a cell divides.

• They allow random distribution of genetic material when a cell divides.

• They allow all genes to be expressed at the same time.

• They eliminate the need for a nuclear membrane.

Multiple Select

As a result of mitosis, the cells of a multicellular organism share which of these properties? Select TWO correct answers.

• All cells have the same number of chromosomes.

• The number of chromosomes varies among cells.

• All cells have identical genetic information.

• Genetic information varies among the cells.

Multiple Choice

The drug colchicine inhibits the formation of spindle fibers during mitosis. If you treat dividing plant cells with colchicine, what would you expect the result to be?

• The chromosomes are halved during cell division. The result is a cell that has half the number of chromosomes than it would normally have.

• The chromosomes do not pull apart in an orderly fashion during cell division. The result is two cells with unequal numbers of chromosomes.

• The chromosomes are separated during prophase. Each of the four daughter cells receives a haploid number of chromosomes.

• The chromosomes do not pull apart during cell division. The result is a cell that has double the number of chromosomes than it would normally have.

Multiple Choice

Humans and other animals regulate cell growth and cell division. In humans, which of these types of cells generally do not divide after they have developed?

• skin cells

• cells of the lining of the digestive tract

• cells in the bone marrow that generate blood cells

• muscle cells and nerve cells

Multiple Select

By regulating the cell cycle, multicellular organisms gain which of these benefits? Select all that apply.

• eliminating unnecessary gene

• healing wounds effectively

• replacing lost cells, such as shed skin cells

• preventing communication among cells

Multiple Choice

How does apoptosis relate to cancer cells?

• In cancer cells, too much apoptosis occurs, resulting in malignant cells that will not undergo programmed cell death.

• In cancer cells, too little apoptosis occurs, resulting in malignant cells that will not undergo programmed cell death.

• In cancer cells, apoptosis occurs only when cells grow without proper regulation.

• In cancer cells, apoptosis occurs only when the cells receive the proper hormones.

Multiple Select

What is the relationship between mutation, the cell cycle, and and cancer? Select all that apply.

• Mutated, defective genes may cause cells to become unable to respond to signals that regulate the cell cycle.

• As a result of unregulated cell cycles, cells may become cancerous, meaning that the cells grow and divide uncontrollably.

• Mutated genes typically allow cells to respond to checkpoint proteins that halt the cell cycle, thus avoiding formation of tumors.

• Cancerous cells may form malignant tumors that invade and destroy surrounding healthy tissue.

Multiple Choice

An embryo grows into a multicellular organism made of a wide variety of cell types. How does the variation in cell types occur?

• Each type of specialized cell produces another type in an ordered sequence.

• Muscle and connective tissue in the embryo produce the other types of specialized cells.

• Embryonic stem cells divide to produce all types of specialized cells.

• Embryonic stem cells divide to produce nerve cells, which produce all types of specialized cells.

Multiple Choice

During the development of a multicellular organism, which cells are totipotent?

• the fertilized egg and the cells produced by the first few cell divisions

• all cells of the blastocyst, which is a hollow ball of cells and an early embryonic stage

• the germ layers of later embryonic stages

• certain cells in the growing regions of the adult organism

Multiple Choice

Which is the most likely application of stem cell research?

• a cure for cancer, a disease in which cells divide rapidly and without proper control

• a treatment for viral infections, in which viruses invade cells

• a treatment for macular degeneration, in which cells of the eye are damaged or killed

• a cure for genetic disorders, which are inherited from either or both parents