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Tamil Nadu Board 12th Standard Bio-Botany - Chapter 5: Book Back Answers and Solutions

This post covers the book back answers and solutions for Chapter 5 – Bio-Botany from the Tamil Nadu State Board 12th Standard Bio-Botany textbook. These detailed answers have been carefully prepared by our expert teachers at KalviTips.com.

We have explained each answer in a simple, easy-to-understand format, highlighting important points step by step under the relevant subtopics. Students are advised to read and memorize these subtopics thoroughly. Once you understand the main concepts, you’ll be able to connect other related points with real-life examples and confidently present them in your tests and exams.

By going through this material, you’ll gain a strong understanding of Bio-Botany Chapter 5 along with the corresponding book back questions and answers (PDF format).

Question Types Covered:

1 Mark Questions: Choose the correct answer, Fill in the blanks, Identify the correct statement, Match the following
2 Mark Questions: Answer briefly
3, 4, and 5 Mark Questions: Answer in detail

All answers are presented in a clear and student-friendly manner, focusing on key points to help you score full marks.

All the best, Class 12 students! Prepare well and aim for top scores. Thank you!

Unit 5 - Plant Tissue Culture

I. Multiple Choice Questions

1. Totipotency refers to
a) capacity to generate genetically identical plants.
b) capacity to generate a whole plant from any plant cell / explant.
c) capacity to generate hybrid protoplasts.
d) recovery of healthy plants from diseased plants.
Answer Key:
b) capacity to generate a whole plant from any plant cell / explant.

2. Micro propagation involves
a) vegetative multiplication of plants by using micro-organisms.
b) vegetative multiplication of plants by using small explants.
c) vegetative multiplication of plants by using microspores.
d) Non-vegetative multiplication of plants by using microspores and megaspores.
Answer Key:
b) vegetative multiplication of plants by using small explants.

3. Match the following :

Column A	Column B
1) Totipotency	A) Reversion of mature cells into meristerm
2) Dedifferentiation	B) Biochemical and structural changes of cells
3) Explant	C) Properties of living cells develops into entire plant
4) Differentiation	D) Selected plant tissue transferred to culture medium

1 2 3 4
a) C A D B
b) A C B D
c) B A D C
d) D B C A
Answer Key:
a) C A D B

4. The time duration for sterilization process by using autoclave is ______ minutes and the temperature is _______
a) 10 to 30 minutes and 125° C
b) 15 to 30 minutes and 121° C
c) 15 to 20 minutes and 125° C
d) 10 to 20 minutes and 121° C
Answer Key:
b) 15 to 30 minutes and 121° C

5. Which of the following statement is correct
a) Agar is not extracted from marine algae such as seaweeds.
b) Callus undergoes differentiation and produces somatic embryoids.
c) Surface sterilization of explants is done by using mercuric bromide
d) PH of the culture medium is 5.0 to 6.0
Answer Key:
b) Callus undergoes differentiation and produces somatic embryoids.

6. Select the incorrect statement from given statement
a) A tonic used for cardiac arrest is obtained from Digitalis purpuria
b) Medicine used to treat Rheumatic pain is extracted from Capsicum annum
c) An anti malarial drug is isolated from Cinchona officinalis.
d) Anti-cancinogenic property is not seen in Catharanthus roseus.
Answer Key:
d) Anti-cancinogenic property is not seen in Catharanthus roseus.

7. Virus free plants are developed from
a) Organ culture
b) Meristem culture
c) Protoplast culture
d) Cell suspension culture
Answer Key:
b) Meristem culture

8. The prevention of large scale loss of biological interity
a) Biopatent
b) Bioethics
c) Biosafety
d) Biofuel
Answer Key:
c) Biosafety

9. Cryopreservation means it is a process to preserve plant cells, tissues or organs
a) at very low temperature by using ether.
b) at very high temperature by using liquid nitrogen
c) at very low temperature of -196 by using liquid nitrogen
d) at very low temperature by using liquid nitrogen
Answer Key:
c) at very low temperature of -196 by using liquid nitrogen

10. Solidifying agent used in plant tissue culture is
a) Nicotinic acid
b) Cobaltous chloride
c) EDTA
d) Agar
Answer Key:
d) Agar

II. Short Answer Questions

1. What is the name of the process given belaw? Write its 4 types.

The name of the process given below is basic steps in plant tissue culture technology.
1. Isolation of cells 2. Culture condition 3. Induction of callus 4. Embryogenesis.

2. How will you avold the growing of microbes in nutrient medium during culture process? What are the techniques used to remove the microbes?

Sterilization is a process to avoid the growing of microbes in nutrient medium during culture process.
The techniques used to remove the microbes in nutrient medium
Culture media are dispensed in glass containers, plugged with non-absorbent cotton or sealed with plastic closures.
Then sterilized using autoclave at 15 psi (121°C) for 15 to 30 minutes.
The plant extracts, vitamins, amino acids and hormones are sterilized by passing through Millipore filter with 0.2 mm pore diameter.
Then added to sterilized culture medium inside Larminar Airflow Chamber under sterile condition

3. Write the various steps involved in cell suspension culture.

The culture of single cells or aggregates of cells in vitro in liquid medium is known as cell suspension culture.
The cell suspension is prepared by transferring a portion of callus to the liquid medium and agitated using rotary shaker instrument.
The cells are separated from the callus tissue and used for cell suspension culture.

4.What do you mean Embryoids? Write its application.

The formation of embryos from the callus tissue directly are called somatic embryogenesis.
These embryos are called Embryoids.
Appilcations of somatic embryogenesis
It provides potential plantiets which after hardening period can establish into plants.
Somatic embryoids can be used for the production of synthetic seeds.
Somatic embryogenesis is now reported in many plants.
Example: Allium sativum, Hordeum vulgare, Oryza sativa, Zea mays.
Synthetic seeds are produced by encapsulation of embryoids in agarose gel or calcium alginate.

5. Give the examples for micro propagation performed
plants.

Pineapple, banana, strawberry and potato are the examples for micro propagation performed plants.

6. Explain the basic concepts Involved in plant tissue culture.

Basic concepts of plant tissue culture are totipotency, differentiation, dedifferentiation and redifferentiation.
Totipotency
The property of live plant cells that they have the genetic potential when cultured in nutrient medium to give rise to a complete individual plant.
Differentiation
The process of biochemical and structural changes by which cells become specialized in form & function. (Meristematic tissue into mature cells i.e simple or complex tissue).
Dedifferentiation
The reversion of mature cells to the meristematic state leading to the formation of callus is called dedifferentiation.
Mature cells into the meristematic i.e formation of callus
Redifferentiation
The component cells of callus have the ability to form a whole plant in a nutrient medium is called redifferentiation. (Callus into whole plant)

7. Based on the material used, how will you classify the
culture technology? Explain it.

Based on the explants the culture technology types are
1. Organ culture 2. Meristem culture 3. Protoplast culture i). Isolation ii). Fusion iii). Culture iv). Selection of somatic hybrid cells 4. Cell culture.
1. Organ culture:
The culture of embryos, anthers, ovaries, roots, shoots ar other organs of plants on culture media is called organ
Culture.
2. Meristem Culture:
The culture of any plant meristematic tissue on culture media is called meristem culture.
3. Protoplast Culture:
Protoplasts are cells without a cell wall but bounded by a plasma membrane.
The fusion product of two protoplasts without nucleus of different cells is called a cybrid.
Following this nuclear fusion happen. This process is called somatic hybridization.
4. Cell Suspension Culture
The culture of single cells or aggregates of cells in vitro in liquid medium is known as cell suspension culture.

8. Give an account on Cryopreservation.

The protoplasts, cells, tissues, organelles, organs, extracellular matrix, enzymes or any other biological materials are preserved by-196°C using liquid nitrogen are called cryopreservation,
It also known as Cryo-conservation.
At this extreme low temperature any enzymatic or chemical activity of the biological material will be totally stopped.
This leads to preservation of material in dormant status.
Later these materials can be activated by bringing to room temperature slowly for any experimental work.
Protective agents like dimethyl sulphoxide, glycerol or sucrose are added before cryopreservation process.
Protective agents are protect the cells, or tissues from the stress of freezing temperature.

9.What do you know about Germplasm conservation.
Describe it.

The conservation of living genetic resources like pollen, seeds or tissue of plant material are called germplasm conservation
It maintained for the purpose of selective plant breeding, preservation in live condition.
It is used for many research works.
It is a part of collection of seeds and pollen that are stored in seed or pollen banks.
So as to maintain their viability and fertility for any later use. Example. Hybridization and crop improvement.
It may also involve a gene bank, DNA bank of elite breeding lines of plant resources for the maintenance of biological diversity and also for food security.

10. Write the protocol for artificial seed preparation.

Artificial seeds or synthetic seeds (synseeds) are produced by using embryoids (somatic embryos).
This is obtained through in vitro culture.
They may even be derived from single cells from any part of the plant,
Later divide to form cell mass containing dense cytoplasm,
large nucleus, starch grains, proteins, and oils etc.,
To prepare the artificial seeds different inert materials are used for coating the somatic embryoids like agrose and sodium alginate.

III. Long Answer Questions

12th bio botany

IV. Exercise

12thbio botany