Maharashtra Board Class 10 Science Part 2 Chapter 8 Cell Biology and Biotechnology PDF Download

Cell Biology And Biotechnology

Can You Recall

1. What is cell?

2. What is tissue? Which are the functions of tissue?

3. Which technique in relation to tissues have you studied in earlier classes?

4. Which are the various processes in tissue culture?

We have studied the plant production by technique of tissue culture in the last class. Stem cells are used for that purpose. Whether such stem cells are present in animals?

Assign names in the figure given below. Explain the various stages those are kept blank.

Cytology

Earlier, we have studied the structure, types and organelles of the cell. This is called as cell biology or cytology. Besides above mentioned points, it includes the study of cell division and many other aspects of the cell.

There are revolutionary changes in the field of human health due to cell biology. Research institutes specially dedicated for research on cells are established at Pune and Bengaluru, India. National Center for Cell Science at Pune and Instem at Bengaluru are involved in valuable research.

Visit both the websites mentioned above and with the help of your teacher, try to understand the research undergoing in those institutes.

Teacher's Note

Cell biology helps doctors cure many diseases. Just like we visit a doctor when we are sick, scientists study cells to find new medicines.

Exam Trick

Remember: Cytology = Study of cells. Cyto means cell, and logy means study. Just like biology is the study of life!

Points to Remember

Cell biology studies cell structure, types, and organelles.
It also includes the study of cell division.
Research institutes in Pune and Bengaluru work on cell science.
Cell biology has brought big changes in human health.

Stem Cells

These are special types of cells present in the body of multicellular organisms. These cells give rise to all other types of cells present in the body of multicellular organisms. Similarly, these cells play an important role in wound healing.

We had studied the stem cells of plants in the previous class. Now, we shall study the stem cells in animals, particularly in human beings.

New organism is formed from the zygote that is formed by union of male and female gamete. At the earliest stage of development, organism is in the form of a mass of cells. All the cells in that mass are almost alike. Those cells are called as stem cells.

Use Your Brain

Stem cells are present in the umbilical cord by which the fetus is joined to the uterus of the mother. Stem cells are also present in the blastocyst stage of embryonic development. Stem cells are present in red bone marrow and adipose connective tissue of adult human beings. It has become possible to produce different types of tissues and the degenerated part of any organ with the help of these stem cells.

Stem Cell Preservation

For the purpose of preservation, stem cell samples are carefully collected from sources like cord blood, red bone marrow or embryo (blastocyst) and are kept in small, sterile vials. Those vials are kept in liquid nitrogen at -1350C to -1900C.

Teacher's Note

Stem cells are like magic cells that can become any cell in our body. In India, doctors are now using stem cells to help people with broken bones and wounds.

Exam Trick

Remember: Stem cells = Future cells. They can change into any cell type you need. Like a new student who can learn any subject!

Points to Remember

Stem cells can become any type of cell in the body.
They are found in umbilical cord, bone marrow, and embryos.
Stem cells are kept very cold in liquid nitrogen.
They help in healing wounds and growing new organs.
One type of stem cell can make 220 different cells.

Adult Stem Cells

Stem cells can be obtained from the body of adult person too. There are three main sources of stem cells in the body of adult persons. Stem cells can be obtained from red bone marrow, adipose connective tissue and blood. Besides, stem cells can be obtained from cord blood immediate after birth.

Uses of Stem Cells

1. Regenerative Therapy

A. Cell Therapy: Stem cells are used to replace the dead cells in case of conditions like diabetes, myocardial infarction, Alzheimer's disease, Parkinson's disease, etc.

B. To produce blood cells required in conditions like anemia, thalassaemia, leukemia, etc.

2. Organ Transplantation: In case of failure of organs like kidney and liver, those can be produced with the help of stem cells and transplanted.

During further development, these cells form any type of cell, different types of tissues and perform different functions in the body. This is the differentiation of stem cells. However, once the tissues are formed, the cells in those tissues, at the most, can form same types of cells only. This is the case in each part of the body. However, stem cells are present for longer duration in some parts of the body.

Stem Cell Research

In biotechnology, stem cell research is a revolutionary event after cloning. This technique has the potential of bringing about the fundamental changes in the medical science.

Depending upon source, stem cells are of two types as embryonic stem cells and adult stem cells.

Embryonic Stem Cells

Division of the zygote starts and thereby it is converted into embryo. Cells of embryo undergo repeated mitotic divisions. Cell differentiation starts from 14th day of conception. Cells of different organs like osteocytes (bone cells), hepatocytes (liver cells), and neurons are formed due to differentiation. Embryonic cells before differentiation are called as embryonic stem cells.

220 different types of cells in human body are formed from single type cells i.e. embryonic stem cells. Thus, stem cells are primary type of undifferentiated cells with self-multiplying ability and they are parent cells of all types of human cells. This property of stem cells is called as pleuripotency. It has been found that if these stem cells are collected well before the beginning of differentiation on 14th day i.e. during 5th – 7th day and cultured with certain biochemical stimulus in laboratory, as per the stimulus, they can transform themselves into desired type of cells, thereby tissues and finally into organs.

Teacher's Note

Embryonic stem cells are the youngest cells. They can grow into any body part like the way a small seed grows into a big tree with many branches.

Exam Trick

Remember: Embryonic = Baby cells. They are very special because they can become any cell. Adult stem cells can only become a few types of cells.

Points to Remember

Embryonic stem cells come from newly formed embryos.
These cells can change into any type of body cell.
This ability is called pleuripotency.
Cell differentiation starts on the 14th day of conception.
Scientists collect these cells between 5th to 7th day for research.

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