One of the major differences between plants and animals is t

One of the major differences between plants and animals is the former’s ability to grow throughout its life time. Read the following article about stem cells in plants: Tiny molecules preserve stem cells:(https://www.sciencedaily.com/releases/2013/01/130122101445.htm) Research shows what makes constant plant growth possible, and then answer the questions that follow.(USE YOUR OWN WORDS)

(3) What is a micro-RNA? (See Chapter 18.3, p. 374, if you would like to know more about micro-RNAs.) What is the role of the “stem cell preserver” micro-RNA the investigators found in Arabidopsis?

(4) What features (structural or otherwise) of the micro-RNA do you think were important for its selection by nature as the stem cell preserver?

Please use your own words!

Solution

What are micro RNA?

Micro RNAs are molecules of RNA that are very small in size. They are a class of RNA molecules that do not code for a protein. They are single stranded RNA molecules approximately 22 nucleotides in length.

What is the role of the “stem cell preserver” micro-RNA the investigators found in Arabidopsis?

            The meristems in plants are a group of cells capable of continuous division over the lifecycle of the plant and therefore continually give rise to new shoots and roots. While the main meristematic cell keeps dividing and remains meristematic, other cells formed from the meristematic cell differentiate and form different types of cells and do different functions. The meristems – which continually divide without undergoing differentiation are believed to be stem cells in plants.

            Scientists have discovered a micro- RNA that signals divided meristematic cells to differentiate into other type of cells. The “Stem cell preserver” microRNA prevents the stem cells from differentiating into other type of cells. It does this by neutralizing the other microRNA promoting cell differentiation in all the cells where the meristematic cell should not differentiate.

What features (structural or otherwise) of the micro-RNA do you think were important for its selection by nature as the stem cell preserver?