Tag: zoology

Questions Related to zoology

Cellular totipotency was for the first time demonstrated by  _____________.

zoology biotechnology and its applications stem cell stem cells and applications stem cells organ donation and body donation blood and organ donation

  1. F.C. Steward

  2. P. Maheshwari

  3. W.H. Muir

  4. Y.P.S. Bajaj

Show answer
Correct Option: A
Explanation:

A- The capacity to generate a whole plant from any cell or explant is called totipotency. The first evidence of totipotency was given by F.C.Steward et al in 1950 in USA.

The inherent capacity of a cell to regenerate a new whole organism or plant is called as

zoology biotechnology and its applications stem cell stem cells and applications stem cells organ donation and body donation blood and organ donation

  1. Ontogeny

  2. Totipotency

  3. Differentiation

  4. Homeostasis

Show answer
Correct Option: B
Explanation:
The inherent potentiality of a plant cell to give rise to a whole plant is described as cellular totipotency. This is a capacity which is retained even after a cell has undergone final differentiation in the plant body. In plants, even highly mature and differentiated cells retain the ability to regenerate to a meristematic state as long as they have an intact membrane
system and a viable nucleus. This is contradicting to animals, where differentiation is generally irreversible. Totipotent cells can form all the cell types in a body, plus the extra embryonic, or placental, cells. Embryonic cells within the first couple of cell divisions after fertilization are the only cells that are totipotent in animals.
Therefore, the correct answer is option B.

Which one of the following is the true definition of totipotent cell? 

zoology biotechnology and its applications stem cell stem cells and applications stem cells organ donation and body donation blood and organ donation

  1. An undifferentiated cell capable of developing into an organ.

  2. An undifferentiated cell capable of developing into a system or entire plant.

  3. Cells that lack the capability of differentiating into an organ or system.

  4. Undifferentiated cells capable of developing into complete embryo.

Show answer
Correct Option: B
Explanation:
Totipotency is defined as the ability of a single cell to get differentiated, including extraembryonic tissues. Totipotent cells formed during sexual and asexual reproduction include spores and zygotes. Thus, each totipotent cell is a self-contained entity that can give rise to the whole organism. 
So, the correct answer is option B.

The term 'totipotency' means

zoology biotechnology and its applications stem cell stem cells and applications stem cells organ donation and body donation blood and organ donation

  1. A group of animals of unrelated characters

  2. The capacity of a cell to regenerate into a whole plant

  3. Hybrids formed as a result of somatic hybridization

  4. Sexually produced offsprings

Show answer
Correct Option: B
Explanation:

Totipotency is the ability of cells such as an embryonic stem cell to differentiate into any type of body cell. Plant cells are also totipotent, which helps to explain why a graft of a plant can generate a whole new individual out of just a small branch cutting.

What are stem cells?

zoology biotechnology and its applications stem cell stem cells and applications stem cells organ donation and body donation blood and organ donation

  1. Ability of renew themselves

  2. Do not have a ability of renewal

  3. Totipotent

  4. Both A and C

Show answer
Correct Option: D
Explanation:
  • Stem cells are cells found in most, if not all, multicellular organisms.
  • They are characterized by the ability to renewing themselves through mitotic cell division and differentiation into the diverse range of specialized cell types. Example: bone marrow cells.
    Hence, option D is correct.

Stem cell therapy was first done by

zoology biotechnology and its applications stem cell stem cells and applications stem cells organ donation and body donation blood and organ donation

  1. James E. Till.

  2. Ernest A. McCulloch.

  3. Eva Engvall.

  4. Both A and B.

Show answer
Correct Option: D
Explanation:

The technique in which the stem cells are transplanted from donor into the patient for production of the new cells is known as the stem cell therapy. This technique was performed by James E. Till and Ernest A. Mc Culloch. These scientists were performing experiments on the bone marrow of the mice using radiations. They discovered the existence of the stem cells in the bone marrow.

Thus, the correct answer is option D. 

Hematopoietic stem cell transplantation can be

zoology biotechnology and its applications stem cell stem cells and applications stem cells organ donation and body donation blood and organ donation

  1. Autologous.

  2. Allogeneic.

  3. Syngeneic.

  4. All of the above.

Show answer
Correct Option: D
Explanation:

Hematopoietic stem cells are obtained from the bone marrow and used for transplantation. There are different types of transplantations in which the donor from which the stem cells are received differs. In the case of the autologous stem cell transplantation, the stem cells are obtained from the same individual. In an allogeneic system, the stem cells can be obtained from any related or non-related person who is compatible with the patient. In the syngeneic stem cell transplantation, the stem cells are obtained from the identical twin.

Thus, the correct answer is option D. 

Stem cells can be

zoology biotechnology and its applications stem cell stem cells and applications stem cells organ donation and body donation blood and organ donation

  1. Pluripotent.

  2. Multipotent.

  3. Totipotent.

  4. All of the above.

Show answer
Correct Option: D
Explanation:

Stem cells are the cells which can form different cells which can differentiate and perform different functions. The pluripotent stem cells are the cells which can generate all the cells in the body of an organism. The multipotent stem cells are cells which can form more than one type of cell. The totipotent cells are the cells which can differentiate to form all the type of cells in the body as well as the extraembryonic structures like the placenta. 

Thus, the correct answer is option D. 

The stem cells required for embryonic stem cell culture is obtained from the

zoology biotechnology and its applications stem cell stem cells and applications stem cells organ donation and body donation blood and organ donation

  1. Blastocyst.

  2. Liver.

  3. Umbilical cord.

  4. None of the above.

Show answer
Correct Option: A
Explanation:

The inner cells present in the blastocyst are the embryonic stem cells. When the embryonic culture is performed for obtaining the stem cells, the embryo is cultured till the blastocyst stage. The cells present as the inner cell mass are removed which act as a source of pluripotent stem cells which can differentiate into cells of the complete body.

Thus, the correct answer is option A. 

Which of the following is a cryoprotectant?

zoology biotechnology and its applications stem cell stem cells and applications stem cells organ donation and body donation blood and organ donation

  1. Mannitol

  2. DMSO

  3. Ethylene oxide

  4. All of the above

Show answer
Correct Option: B
Explanation:

The cells, tissues, semen and embryo can be preserved for longer periods at lower temperatures using cryopreservation. When the cells are frozen, there is formation of ice crystals in the cells which will rupture the cells. The cryoprotectants like DMSO (dimethylsulphoxide) prevents the formation of these crystals when the cells are stored in liquid nitrogen. 

Thus, the correct answer is option B.