Holoblastic Cleavage vs Meroblastic Cleavage – What is the Difference?

Holoblastic Cleavage and Meroblastic Cleavage – What is the Difference?

When we are studying embryology, it becomes confusing sometimes if we don’t clearly remember what holoblastic and meroblastic means! So in this video we will see holoblastic and meroblastic cleavage and different type of eggs which come under these two categories. And at the end as always I will give you my trick which helps me remember this concept in super easy way. So let us begin 🙂
To read blog post on this topic which can be your quick short note 🙂 visit http://nowiknow.co.in/2017/01/25/holoblastic-cleavage-vs-meroblastic-cleavage/

Totipotent, Pluripotent and Multipotent Stem Cells – What is the Difference?

Totipotent, Pluripotent and Multipotent Stem Cells – What is the Difference?

In this video let us talk about few terms that we frequently use when we talk about stem cells and they can be really confusing sometimes. I am talking about totipotent, pluripotent and multipotent stem cells. Like always first thing first. What are stem cells? Stem cells are undifferentiated, unspecialized cells which mean stem cells can differentiate into any type of cell present in our body and we have around 200+ cell types in our body and stem cell can give rise to any of them.

To understand these three terms we should know the categories of stem cells. Stem cells are classified under two categories, embryonic stem cells – found in embryo and adult stem cells – found in many organs. Embryonic stem cells can be either totipotent or pluripotent and adult stem cells are multipotent.

  1. Totipotent – “totus” means “whole”. The ability of zygote that it can differentiate into any type of cell (making a complete organism) is called totipotency. That is why a zygote is totipotent.
  2.  Pluripotent – “pluri” means “several”. The inner cell mass of the blastocyst has the ability to produce all the cell types of our body except for what trophoblast can form e.g., placenta, amniotic sac etc. So this means we have around 200+ cell types in our body and inner cell mass can differentiated into any of them, e.g., it can give rise to all the blood cells, cardiac muscles, neural cells. This ability of inner cell mass is called pluripotency. That is why inner cell mass is pluripotent.
  3. Multipotent – “multi” in this case means “few”. Pluripotent cells, as we already establish can differentiate in any of the cell type but multipotent cell would be more specified for one or more cell lines e.g., mesenchymal stem cell differentiates to form bone, cartilage, connective tissue, adipose tissue etc. So mesenchymal stem cell is multipotent.

Watch the video for better explanation.


Read short notes on this topic here

Read more about stem cells.