Botany: Solved Previous Year’s Question Paper for   NCERT/ CBSE  Class 12th Botany Paper Code (SEIIKPJXII-34019-A)

 (Long Answer Type Questions) 

Question: (a) Draw a labelled diagram of an albuminous seed (L.S.). 

Ans: The following elements make up an average albuminous seed:

1. The outer seed coat, is a thick coating of cells-based protection on the outside of the seed.

2. Endosperm – A tissue used for storage that has a lot of carbohydrates, proteins, and oils.

3. Embryo: A little object that includes the embryo itself, the hypocotyl, the cotyledons, and the radicle.

4. Cotyledons – The first structures to form in the embryo, these are the main nourishment sources for the growing plant.

5. Radicle: The embryonic plant’s first root.

Question: (b) How are seeds advantageous to flowering plants? 

Ans: The benefits of seeds for flowering plants are numerous.

1. They give the plant a means of reproduction, enabling it to disperse its genetic material and raise its chances of survival.

2. They serve as a food source and a type of protection for the plant’s embryos and sprouting seedlings.

3. The plant can travel to new locations and colonise new environments through the use of seeds, which is another method of dissemination.

4.  The plant may tolerate harsh conditions till it can blossom and multiply once again thanks to the seeds it stores.

Question: Briefly describe the chromosomal basis of inheritance. 

Ans: The concept that chromosomes serve as carriers of genetic material from parents to offspring is known as the chromosomal basis of inheritance. Genes, the genetic building blocks that pass on information from one generation to the next, are found on chromosomes. The arrangement of genes on chromosomes, in particular their order and structure, is what enables the inheritance of traits from one generation to the next.

 (Short Answer Type Questions) 

Question: What are the essential requirements of genetic material?

Ans: 1. It needs to have the ability to duplicate or create duplicates of itself.

2. It should have the capacity to transmit and store genetic data.

3. It must be capable of mutations to serve as the starting point for evolution.

4. For genetic information to have phenotypic effects, it must be expressed in some way, such as through proteins.

5. It should be transferable from one generation to the next.

Question: Write a note on Biopiracy. 

Ans: Biopiracy is the act of appropriating naturally occurring biological resources (such as plants, animals, microbes, and genetic material) without the community’s or the country’s agreement or payment to the source. With the development of biotechnology, it has grown to be a contentious problem and is a type of intellectual property theft. When conventional knowledge, such as medical procedures, is used without authorization to profit financially, this is known as biopiracy. This procedure frequently entails taking advantage of Indigenous peoples’ intellectual property rights, which they have developed over many generations as they have utilised and improved their traditional knowledge. Patenting genetic resources and traditional knowledge to use them for financial advantage is another aspect of biopiracy. Local communities may be displaced as a result, and their traditional knowledge may be lost. As the world’s biodiversity resources are being quickly depleted, biopiracy has grown to be a significant issue. Biopiracy undercuts Indigenous communities’ rights and jeopardises their access to natural resources by allowing businesses to patent and profit from their traditional knowledge. The value of indigenous peoples’ traditional wisdom in preserving and restoring biodiversity must be understood.

Question: Describe the various applications of Tissue Culture in brief.

Ans: Cells and tissues can be grown in a lab setting using the technique known as tissue culture. It is employed in numerous fields of study and application, such as:

1. Plant propagation: Plant clones can be made using tissue culture to multiply a particular kind of plant.

2. Pharmaceuticals: Human or animal cells are produced for therapeutic purposes via tissue culture, which is also used to test the efficacy of novel medications.

3. Agriculture: Crop plants’ traits, such as increased yields and disease resistance, can be improved through tissue culture.

4. Animals: Tissue culture is used to create new animal types, such as those with certain traits or qualities.

5. Biotechnology: Tissue culture is used to create transgenic organisms and vaccines, among other biotechnology-related goods.

Question:  Give an account of Ecological Succession. 

Ans: The process of a biological community’s species makeup changing through time is known as ecological succession. When new species are introduced to an existing environment, whether through natural processes or human influence, it is a natural process that takes place. The environment will alter as a result of the new species’ competition with already existing species, including changes to soil composition, plant and animal populations, and the physical environment. Primary succession happens in freshly created habitats, such as when islands are created or life is introduced to an arid area. Pioneer species, or species that are well adapted to severe settings and are the first to colonise a new ecosystem, are what drives this sort of succession. More species can establish themselves as these pioneer species start to change their habitat, and starts to become more friendly. The recolonization of species that have adapted to the new environment is what causes secondary succession in ecosystems that have been disturbed, such as by fire or flooding. Since the ecosystem has already undergone some change and the species that colonise it are better adapted to the new conditions, secondary succession in this situation typically occurs much faster than primary succession. A mature ecosystem, also known as a climax community, is the result of succession and is characterised by stable species composition and physical environment. Many species depend on succession to survive and this is a crucial mechanism in maintaining the harmony of nature.

(Very Short Answer Type Questions) 

Question: What is Double fertilisation? 

Ans: When two sperm cells and two egg cells combine to generate a zygote and a triploid endosperm in plants, this process is known as double fertilisation. It is a crucial stage in the reproduction of angiosperms since it starts the embryonic and endospermic development, both of which are necessary for the seed’s growth.

Question: Explain predation with an example. 

Ans: Predation is a sort of connection where one living thing (the predator) catches and consumes the other (the prey). A lion killing and eating an antelope is an illustration of predation. The antelope is the prey in this scenario, and the lion is the predator.

Question: Why a need is felt to conserve biodiversity? 

Ans: The preservation of biodiversity is crucial for the survival of our planet and the well-being of our environment, our economy, and ourselves. Clean air, clean water, and a stable climate are all made possible by biodiversity, which is the variety of life that exists within ecosystems. Additionally, it offers us other necessities for our survival, such as food, medication, and other resources. By protecting species and habitats that are necessary for a healthy world and ecosystem, we are guaranteeing that future generations can continue to take advantage of these crucial resources.

Question: List the effect of Ozone depletion. 

Ans: 1. Enhanced Skin Cancer Risk: Ozone depletion increases the quantity of ultraviolet radiation (UV-B) that reaches the Earth’s surface, enhancing the risk of skin cancer and other health issues.

2. Crop Damage: Because certain plants are harmed by UV-B radiation, ozone depletion can result in crop damage and a reduction in agricultural production.

3. Global Warming: Ozone depletion increases atmospheric carbon dioxide concentrations, which in turn causes global warming.

4. Damage to Marine Life: Because increasing UV-B radiation hurts marine organisms, ozone depletion might cause their demise.

5. Ozone Layer Damage: Ozone depletion can cause the ozone layer to become damaged, which will cause more ozone depletion.

(Objective Type Questions) 

Question: Removal of Anthers from a bisexual flower to make it a female flower 

Ans: Emasculation.

Question: The flow of energy in an ecosystem is unidirectional. 

 (Give the technical one word) 


Ans: False

Question: Green house effect is due to: 

(a) SO2 

(b) CO2 

(c) CO 

(d) O2 

Ans: (b) CO2

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