Chapter 10 Flash Cards

For ch.10 test freeee

What are some of the difficulties a cell faces as it increases in size?

1. As a cell grows, it places increasing demands on its DNA. Eventually, the cell's DNA would no longer be able to serve the increasing needs of the growing cell.

2. The larger a cell becomes, the less efficient it is in moving nutrients and waste materials across its cell membrane.

3. As a cell grows, its ratio of surface area to volume decreases. This makes it harder for the cell to move enough nutrients and wastes across the cell membrane to support its increasing volume.

What is asexual reproduction?

A type of reproduction that involves a single parent producing genetically identical offspring

What is sexual reproduction?

A type of reproduction in which two parents produce offspring that inherit some genetic information from each parent.

How does surface area relate to cell volume?

As a cell increases in size, its volume increases faster than its surface area. This is because the volume is calculated by length x width x height, while the surface area is calculated by (length x width) x 6 sides.

What is the role of chromosomes in cell division?

Chromosomes make it possible to separate DNA precisely during cell division.

What are the main events of the cell cycle?

The cell cycle is a series of events that cells go through as they grow and divide. The four phases of the cell cycle are:

G1 phase: Cell growth

S phase: DNA replication

G2 phase: Preparation for mitosis

M phase: Cell division (mitosis and cytokinesis)

What are the four phases of mitosis, in order?

Prophase, Metaphase, Anaphase, Telophase

What are the main events of prophase?

1. Genetic material condenses into chromosomes.

2. The centrioles separate, and a spindle begins to form.

3. The nuclear envelope breaks down.

What are the main events of metaphase?

1. The centromeres of duplicated chromosomes line up across the center of the cell.

2. Spindle fibers connect to each chromosome's centromere and to the two poles of the spindle.

What are the main events of anaphase?

1. Sister chromatids suddenly separate and begin to move apart.

2. Each sister chromatid is considered an individual chromosome.

3. The chromosomes separate and move along spindle fibers to opposite ends of the cell.

What are the main events of telophase?

1. Chromosomes begin to spread out into a tangle of chromatin.

2. A nuclear envelope reforms around each cluster of chromosomes.

3. The spindle breaks apart.

4. A nucleolus becomes visible in each daughter nucleus

What is cytokinesis?

The division of the cytoplasm.

How does cytokinesis differ in animal and plant cells?

1. Animal cells: The cell membrane draws inward, eventually pinching off to form two daughter cells.

2. Plant cells: A structure called the cell plate forms midway between the divided nuclei, creating a new cell wall.

How is the cell cycle regulated?

1. Internal regulators respond to events inside the cell, such as the replication of chromosomes.

2. External regulators respond to events outside the cell and direct cells to speed up or slow down the cell cycle.

What are cyclins?

A family of proteins that regulate the cell cycle in eukaryotic cells. Cyclin production signals cells to enter mitosis, while cyclin destruction signals cells to stop dividing.

Why is cancer considered a disease of the cell cycle?

Cancer cells lose the ability to control their growth. They do not respond to the signals that regulate the growth of most cells. As a result, cancer cells divide uncontrollably and can form tumors.

How do cells become specialized for different functions?

Through the process of differentiation, cells become specialized in structure and function. During the development of an organism, cells differentiate into many types of cells.

What are stem cells?

Unspecialized cells from which differentiated cells develop.

What are the three types of stem cells and what is their potential for differentiation?

1. Totipotent: Can develop into any type of cell in the body. Only the fertilized egg and the cells produced by the first few cell divisions of embryonic development are truly totipotent.

2. Pluripotent: Can develop into nearly any cell type in the body. Cells of the inner cell mass are pluripotent.

3. Multipotent: Can develop into many, but not all, types of cells. Adult stem cells are multipotent.

What are some possible benefits and issues associated with stem cell research?

Potential benefits:

1. Stem cells offer the potential benefit of using undifferentiated cells to repair or replace badly damaged cells and tissues.

2. Stem cell research could lead to new ways to treat diseases like diabetes and spinal cord injuries.

Potential issues:

1. Human embryonic stem cell research is controversial because the arguments for it and against it both involve ethical issues of life and death.

2. Much more research is needed to understand the risks and benefits of stem cell therapies.