Differentiation Study Guide

DIFFERENTIATION OF THE CELL

Bio.2.5 Levels of Organization

Construct an explanation about the role of mitosis in the production, growth, and maintenance of systems within complex organisms. Emphasize the major events of the cell cycle including cell growth and DNA replication, separation of chromosomes, and separation of cell contents. (LS1.B)

Complex organisms are made of interacting systems, which are made up of cells. Use the information in this chapter to determine the role that cell division plays in the maintenance of systems in an organism.

How do cells become different types of cells?  How do the stem cells of an embryo become skin cells, nerve cells and blood cells?

Differentiation

Every cell in the body originates from a single fertilized egg called a zygote. The zygote divides repeatedly to produce an embryo. These embryonic cells continue to divide. If the DNA is replicated and every daughter cell has the same DNA as the parent cell, how is it possible to have so many different cell types?

Differentiation- is the process by which an unspecialized cell, such as a fertilized egg cell, divides many times to produce specialized cells.

During differentiation, certain genes are turned on, or become activated, while other genes are switched off, becoming inactivated. This process is regulated by the cell. A differentiated cell will develop specific structures and perform certain functions.

Different types of cells in the human body are specialized for specific jobs. Do you know the functions of any of the cell types shown here?

Levels of Organization

Cells are the most basic units of life in your body, and each cell is specialized, with a specific function. Nerve cells transmit electrical messages around the body, and white blood cells attack invading bacteria throughout the body. Other cells include specialized cells in the kidney (such as kidney glomerulus parietal cells), brain (such as astrocytes), stomach (such as parietal cells), and muscles (such as red and white skeletal muscle fibers). Specialized cells that work together form tissues. Different tissues work together to form organs, and organs work together in organ systems. For example, the heart, lungs, and blood vessels are some of the organs that work together in the cardiovascular system.

An individual mouse is made up of several organ systems.  The system shown here is the digestive system, which breaks down food into a form that cells can use.  One of the organs of the digestive system is the stomach.  The stomach, in turn, consists of different types of tissues.  Each type of tissue is made of cells of the same types. 

Cell division and differentiation make and maintain specialized cells, which are needed to create the tissues, organs, and organ systems that carry out necessary functions for life. organisms. Thanks to cell division and differentiation, organisms have systems of tissues and organs that work together to meet its needs.

Biological Levels of organization:

Organelle

Cell

Tissue

Organ

Organ System

Organism

Population

Community

Ecosystem

Biosphere

Watch this video on Cell differentiation:

https://www.youtube.com/watch?v=gwAz_BtVuLA

Axolotls are amphibians that can regenerate almost any body part. If they lose a limb, it will grow back. The new limb will have the same structure and function as the original.

1. Revisit your original ideas about how an axolotl can regenerate a lost limb. Use your understanding of cell division and differentiation to revise your explanation.
2. What might be different in the cell cycle and differentiation of axolotl cells that allow them to regenerate limbs?