CELL DIFFERENTIATION 4-4 Notes

Differentiation Cells not only divide by mitosis to make 2 daughter cells, but they also differentiate. Differentiation is the process by which cells change in structure and become capable of carrying out special functions. In other words, cell become different cells so they can do different jobs. Cells then form specialized groups of cells, which form tissues, and then organs.

Specialized Cells Plants have undifferentiated cells in their stems and roots that can give rise to different kinds of cells. Undifferentiated plant cell Leaf cell Transport cell Root cell

Why do cells differentiate? If all of our cells did the same thing, we would not be able to function. We have skin cells for protection. We have white blood cells to fight infections. We have red blood cells to carry oxygen to our organs. We have nerve cells so we can feel. Etc….

How do cells differentiate? DNA provides the instructions to tell the cells what to differentiate into during development. Certain sections of the DNA get turned off, and the ones that are turned on guides how the cell develops. This process is different in different types of organisms. Let’s talk about the differences in plants and animals!

Cell differentiation in Animals Once most human cells differentiate, they can no longer become other types of cells. For example, a red blood cell will never become a skin cell. BUT humans have stem cells throughout their bodies that can differentiate into other cells, based on what the body needs. For example, your body always needs to make new red blood cells to replace old ones that die.

Here are some examples of stem cell differentiation.

Cells at the point of injury can differentiate to form new muscle, bone, blood, and nerves. This is why some lizards and insects can grow new tails or limbs.

Cell differentiation in Plants Unlike animals, plants continue to grow throughout their lives. They have special cells that can undergo rapid cell division and differentiation, thus constantly increasing the size of their roots and stems. This may also lead to the growth of new roots, stems, and leaves. For example, you can cut off the leaves of certain plants, plant them, its stem will grow roots, and a new plant will grow. ALL BECAUSE OF DIFFERENTIATION!!

YUMMY!! You can grow your own pineapple!