The G20 is a worldwide conference that brings together the European Union and the 19 largest economies in the world, which together account for 85% of the world’s economic output. This conference was created in 1999 to advance global economic cooperation, sustainable growth, and stable international finance.
G20: Definition, Themes 2023, Logos, Objectives, History, Agenda and Importance Read More »
Question: Define Immunity. Name its types.
Answer: Immunity is the ability of the body to protect itself from foreign substances, organisms, or toxins.
The three types of immunity are innate immunity, adaptive immunity, and passive immunity.
Zoology: Solved Previous Year Question Paper for NCERT/ CBSE Class 12th Zoology Read More »
Question: Define Fertilization. Briefly enlist the events that take place during Fertilization.
Answer: Fertilization is the fusion of a sperm cell and an egg cell to form a single cell that has genetic material from both the egg and the sperm.
Events that take place during Fertilization:
1. Sperm binds to the egg and penetrates its outer layer.
2. The sperm and egg nuclei fuse, forming a single nucleus.
3. The egg is activated and begins the process of cell division.
4. The zygote begins to divide into two cells, then four cells, and so on.
5. The zygote starts to travel down the fallopian tube towards the uterus.
Question: (i)What is primary productivity ?
(ii) Why does it vary in different ecosystems ?
(ii) State the relationship between gross and primary productivity.
Answer: (i) Primary productivity is the rate at which energy is converted into organic matter by living organisms such as plants within an ecosystem.
(ii) It varies in different ecosystems due to the availability of resources, environmental factors such as temperature and light intensity, and the presence of other organisms.
(iii) The relationship between gross and primary productivity is that gross productivity is the total amount of energy produced by an ecosystem, while primary productivity is the amount of energy converted into organic matter. Gross productivity is the sum of all primary production, as well as respiration processes such as decomposition and consumption.
Question: With the help of a flow diagram explain the flow of energy in an Ecosystem.
Ans: → Solar Energy from Sun → Plants (Photosynthesis) → Consumers (Herbivores) → Consumers (Carnivores) → Decomposers (Bacteria and Fungi) → Nutrients (Carbon Dioxide, Nitrogen, etc.) → Plants (Respiration) → Consumers (Herbivores) → Consumers (Carnivores) → Decomposers (Bacteria and Fungi) → Nutrients (Carbon Dioxide, Nitrogen, etc.) → Solar Energy from Sun
Question: Do you think microbes can also be used as a source of energy? If yes, how?
Ans: Yes, microbes can serve as a source of energy. Biomass may be used by microbes to produce biofuels like ethanol and biodiesel that can replace fossil fuels.
Point out any three advantages of the tissue culture technique
Ans: 1. Rapid Multiplication: Tissue culture is a method for the quick growth of plants and can quickly multiply thousands of plants.
2. Disease-Free Plants: Tissue culture also aids in the production of disease-free, highly pest- and disease-resistant plants.
3. Quality Control: Tissue culture can be used to control plant quality. It assists in preserving the plants’ intended traits.
Define Allogamy
Ans: Allogamy is the process of fertilization between two individuals with different genetic backgrounds.
