BT403 Final Term Past Papers Fall 2020 by Amaan Khan

BT 403 Final terms Current Fall 2020

Qno1: Define Inoculation and their function. 2 marks

Transfer of explant (root, stem, leaf, etc.) on to a culture medium is called inoculation. The inoculation is carried out under aseptic condition for which an apparatus called laminar air flow chamber is used. Flamed and cooled forceps are used for transfer of plant materials to different culture media kept in glasswares.

Qno2: What is Bio compost? 2 marks

It is one of the Eco-friendly products composed of waste material released from sugar industries which are decomposed. It is magnified with human-friendly bacteria, fungi, and various plants.

Qno3: Targets of ROS? 2 marks

ROS is known to cause damages to biomolecules such as lipids, proteins and DNA.

Qno4: What is Biopesticides? 2 marks

Biopesticide is a formulation made from naturally occurring substances that controls pests by non toxic mechanisms and in ecofriendly manner. Biopesticides may be derived from animals (e.g. nematodes), plants (Chrysanthemum, Azadirachta) and micro-organisms (e.g. Bacillus thuringiensis, Trichoderma, nucleopolyhedrosis virus), and include living organisms (natural enemies) etc.

Qno5: What is need germplasm preservation? 2 marks

Germplasm Preservation

• Germplasm is living tissue from which new plants can be grown. It can be a seed or another plant part a leaf, a piece of stem, pollen or even just a few cells that can be turned into a whole plant.
• Germplasm contains the information for a species' genetic makeup, a valuable natural resource of plant diversity.

Qno6: Role of auxin in plants. 3 marks

Role of auxins

• Auxins stimulate cell elongation
• Influence a host of other developmental responses,
• Root initiation, vascular differentiation, tropic responses, apical dominance
• Development of auxiliary buds, flowers and fruits
• Auxins in plant tissue culture are used to induce callus from explants, and cause root and shoot morphogenesis and parthenocarpy.

Qno7: Environmental conditions that causes stress in plants. 3 marks

Environmental conditions that can cause stress

• Water-logging
• Drought
• High or low temperatures
• Excessive soil salinity
• Inadequate mineral in the soil
• Too much or too little light

Qno8: Characteristics of DNA based marker. 3 marks

• The sequence of nucleotides in DNA of an individual is unique and thus determines its identity.
• The ultimate difference between individuals lies in the nucleotide sequence of their DNA.
• These can be used to diagnose the presence of the gene without having to wait for gene effect to be seen.

Qno9: Explain Herbicides action. 3 marks

A herbicide’s effectiveness is strongly influenced by its toxic mode of action and the application method. Herbicides can act by inhibiting a plant’s amino acid production, growth, photosynthesis, cell division, or by mimicking natural auxin hormones to cause deformities. Most modern herbicides are synthetic mimics of a natural plant’s hormones that obstruct the target plant’s growth.

Qno10: Define Herbicides. 2 marks

A herbicide is a chemical substance used to control or manipulate undesirable vegetation, especially weeds. Herbicides are extensively used in gardening, farming, and landscape turf management.

Qno11: What are Somaclonal variations? 3 marks

• In addition to the variants/mutants (cell lines and plants) obtained as a result of the application of a selective agent in the presence or absence of a mutagen, many variants have been obtained through the tissue culture cycle itself.
• These somaclonal variants, which are dependent on the natural variation in a population of cells, may be genetic or epigenetic, and are usually observed in the regenerated plantlets.

Qno12: Why kids are mostly affected by pesticides is compared to adults? 3 marks

Effects of Pesticides on Kids

• Children are especially susceptible to harmful effects of pesticides.
• They can easily become exposed to pesticides (via inhalation or skin contact) in schools, daycare, playgrounds, hospitals, and any other public areas, no matter how careful you are.

Qno13: How can you justify cell suspension? 2 marks

A cell suspension culture consists of cell aggregates dispersed and growing in a moving liquid media.

• It is normally initiated by transferring pieces of undifferentiated and friable callus to a liquid medium, which is continuously agitated by a suitable device.

Qno14: What are the side effects of pesticides to environment? 5 marks

Environmental effects

• Widespread use of pesticides in agriculture has experts worried due to their longterm environmental damage.
• Some pesticides can stick around for years, posing a very real threat to the ecological system and hence human health.
• Excessive and careless use of pesticides can contaminate water sources and soil, make fruits and vegetables less nutritious, and reduce biodiversity.