Here are some reasons why reproduction is important for an organism:

1. Reproduction ensures the continuity of the species
2. Reproduction allows for genetic variation
3. Reproduction can be a source of pleasure

Meiosis is characteristically different from mitosis in the following ways:

1. Meiosis produces haploid cells, while mitosis produces diploid cells.
2. Meiosis involves two rounds of cell division, while mitosis only involves one round.
3. Meiosis is involved in sexual reproduction, while mitosis is involved in asexual reproduction.

Here are five processes of asexual reproduction with one suitable example for each:

1. Binary fission: A single cell divides into two identical cells. This is the most common form of asexual reproduction and is found in bacteria, amoebas, and many other organisms. [Example: E. coli bacteria reproduce by binary fission.]
2. Budding: A small outgrowth, or bud, develops on the parent cell and eventually separates to form a new organism. This type of reproduction is found in yeast, hydras, and some plants. [Example: Yeast reproduce by budding.]
3. Fragmentation: The parent organism breaks into multiple pieces, each of which can develop into a new organism. This type of reproduction is found in many marine organisms, such as sea stars and planarians. [Example: Planarians reproduce by fragmentation.]
4. Spore formation: The parent organism produces spores, which are small, reproductive units that can develop into new organisms. This type of reproduction is found in fungi, algae, and some plants. [Example: Molds reproduce by spore formation.]
5. Vegetative propagation: New plants are produced from parts of the parent plant, such as stems, leaves, or roots. This type of reproduction is found in many plants, such as strawberries, potatoes, and cacti. [Example: Strawberries reproduce by vegetative propagation.]

F2 Phenotypes:

• Black, Coarse-haired (BBRR, BBRr, BbRR, BbRr): 9/16
• Black, Smooth-haired (BBrr, Bbrr): 3/16
• White, Coarse-haired (bbRR, bbRr): 3/16
• White, Smooth-haired (bbrr): 1/16

Conclusion:

The hybridization experiment shows that black color (B) and coarse hair (R) are dominant traits, while white color (b) and smooth hair (r) are recessive traits. The F2 generation exhibits a typical 9:3:3:1 ratio of phenotypes, illustrating Mendel's law of independent assortment.

Symptoms expressed in a child affected with Thalassae:

1. Less formation of Hemoglobin
2. Anaemia
3. Excessive deposition of iron
4. Unusual formation of bones
5. Stunted growth
6. Cardiac problems.

Suggestions to be given at the time of genetic counselling in case of Thalassaemia.

• Carrier couples should not take any child.
• To undergo proper blood lest prior to pregnancy.
• They should be aware of the possible complications of the baby.

Here is a brief outline of the chemical origin of life mentioning Miller and Urey's experiment:

• The chemical origin of life is the study of how life on Earth first arose from non-living matter.
• The Miller-Urey experiment simulated the conditions of the early Earth and showed that organic molecules could form from non-living matter.
• These organic molecules could have been the building blocks of the first living cells.
• There is still much that we do not know about the chemical origin of life, but the Miller-Urey experiment was a major step forward in our understanding.

Here are two major tenets of Lamarck's evolutionary theory:

• Use and disuse: Lamarck believed that organisms could change over time in response to their environment. If an organism used an organ more, it would become stronger and larger. If an organism did not use an organ, it would become weaker and smaller.
• Inheritance of acquired characteristics: Lamarck also believed that these acquired characteristics could be passed on to offspring. For example, if a giraffe's neck became longer because it was constantly reaching for leaves, its offspring would also have longer necks.

Here are the roles of bacteria in three steps of the nitrogen cycle:

Nitrogen fixation: Bacteria are responsible for converting atmospheric nitrogen gas (N₂) into forms that plants can use, such as ammonia (NH₃). This process is called nitrogen fixation.

• Free-living bacteria: Some bacteria, such as Azotobacter and Clostridium, can fix nitrogen in the soil.
• Symbiotic bacteria: Other bacteria, such as Rhizobium, form symbiotic relationships with plants. These bacteria live in nodules on the roots of legumes, such as peas and beans.

Nitrification: Bacteria convert ammonia into nitrites (NO₂^-) and then into nitrates (NO₃^-). This process is called nitrification.

• Nitrosomonas: Bacteria in the genus Nitrosomonas convert ammonia into nitrites.
• Nitrobacter: Bacteria in the genus Nitrobacter convert nitrites into nitrates.

Denitrification: Bacteria convert nitrates back into nitrogen gas. This process is called denitrification.

• Pseudomonas: Bacteria in the genus Pseudomonas can denitrify.
• Thiobacillus denitrificans: Bacteria in the genus Thiobacillus can denitrify.

A luxurious and comfortable lifestyle is one of the major reasons for air pollution. This is because many of the activities that we associate with a luxurious and comfortable lifestyle, such as driving cars, using air conditioners, and burning fossil fuels, produce air pollutants.

Two examples of animal biodiversity endangered by the pollution of the river Ganga

1. Gangetic dolphin
2. Gharial

Here are three incidences which occurred as a result of the disruption of the nitrogen cycle:

• Algal blooms: When the nitrogen cycle is disrupted, it can lead to algal blooms. These are large growths of algae that can occur in water bodies. Algal blooms can be harmful to aquatic life and can also produce toxins that can be harmful to humans.
• Eutrophication: Eutrophication is a process by which water bodies become enriched with nutrients. This can lead to the growth of algae and other aquatic plants, which can eventually deplete the oxygen levels in the water, leading to the death of fish and other aquatic life.
• Nitrate contamination: Nitrates are a form of nitrogen that can be found in groundwater and surface water. When nitrates are present at high levels, they can be harmful to human health. Nitrates can also contribute to the formation of smog.

Due to anthropogenic activity, these are pollution, deforestation and other degradation in the environment. These changes in atmospheric conditions, cause natural changes and global warming. Greenhouse gases are increased. Melting of ice and rise of sea level are occurring. Loss of biodiversity, acid rain, heavy rainfall etc. are other impacts on the environment due to changes in climate and global warming resulting from the increasing human population.

(i) Asthma:

Symptoms can include wheezing, shortness of breath, chest tightness, and coughing.

(ii) Bronchitis-

Symptoms include a productive cough (coughing up mucus), wheezing, shortness of breath, and chest pain.

Disbalance in prey-predator number - The shrinking of mangrove vegetation has resulted in a reduction in the number of herbivores and as a result of which they carni- vores are becoming endangered in this case the number of tigers is going down and moreover they are getting killed. Gradually the ecosystem will be unbalanced.

Destruction of Mangrove plants due to urbanization- Due to urbanization the mangrove plants are destroyed. The destruction of the Mangrove forest and the progressing human settlement has resulted in the loss of habitat for the animals, making them endangered and vulnerable. As a result, they may get extinct in future.

Submergence of Islands Due to rising sea level:-

An increased number of islands are getting submerged due to increasing water levels as a result of which the habitat is getting shrunk and that has reduced the habitat. In want of habitat and food the species of various tropic levels will be lost.

Location of sundaland hotspot:- It is a biogeographical region of South Eastern Asia.

Important species:- Elephant