Question

Define the term tissue and explain the concept of tissue culture?

Answer 1

Groups of cells performing the same function are known as tissues.

Plant tissue culture is the production of new plants from small amounts of plant tissue under carefully controlled laboratory conditions. In this method, some plant tissues are taken under sterile conditions and are kept in test tubes containing culture medium, which allows these cells to grow fast and form an unorganised mass of cells called callus. This callus is transferred into another medium containing proper growth hormones for differentiation and organ formation. As a result, small plantlets are formed in the test tubes. These can be later placed in soil where they can grow into mature plants. This technique is called micro-propagation.

Tissue culture has various applications like:

(i) It is used to produce disease resistant and high yielding varieties of plants.

(ii) Tissue culture is helpful to produce new varieties of plants by fusing two different cells through a technique called germplasm hybridisation and then growing the fused cells through tissue culture. For example: Pomato.

(iii) Tissue culture along with recombinant DNA technology has made it possible to transfer nitrogen fixing genes from bacteria into plants. This has helped these plants to fix atmospheric nitrogen.

(iv) It helps to produce large number of plants in short duration of time and in limited space.

(v) It has made it possible to preserve characteristics of the parent plants.

Answer 2

In biology, a tissue is a group or collection of similar cells that perform a specific function. These cells work together as a unit to carry out particular tasks within an organism. Tissues are organized into various types based on their structure, function, and location in the body. The four primary types of tissues in multicellular organisms are epithelial tissue, connective tissue, muscle tissue, and nervous tissue.

Concept of Tissue Culture:

Tissue culture, also known as cell culture or in vitro culture, is a technique used in biology and biotechnology to grow and maintain cells or tissues outside the organism's body in a controlled environment. This technique involves isolating cells or tissues from a plant or animal source and providing them with suitable nutrients, growth factors, and conditions necessary for their growth and proliferation.

The process of tissue culture typically involves the following steps:

1. Cell or Tissue Isolation: Cells or tissues are isolated from the organism of interest using sterile techniques.

2. Culture Medium Preparation: A culture medium is prepared, which contains essential nutrients, vitamins, minerals, growth factors, and hormones required for cell growth and proliferation. The medium is sterilized to prevent contamination.

3. Cell or Tissue Culture: The isolated cells or tissues are placed onto the culture medium in sterile containers such as Petri dishes, flasks, or culture plates. The containers are then placed in a controlled environment, typically an incubator, where temperature, humidity, and other conditions are carefully regulated to mimic the physiological conditions necessary for cell growth.

4. Cell Growth and Maintenance: Over time, the cells or tissues grow and multiply, forming a mass of cells called a cell line or tissue culture. During this process, the culture medium may need to be replenished periodically to provide fresh nutrients and remove waste products.

Tissue culture techniques have various applications in scientific research, biotechnology, medicine, and agriculture. They are used to study cell biology, develop new drugs and therapies, produce vaccines and recombinant proteins, propagate plants, and preserve endangered species, among other purposes. Tissue culture allows researchers to manipulate and study cells and tissues in a controlled environment, providing valuable insights into their behavior, function, and potential applications.