Answer:
1. Earth's temperature is maintained by re radiated infra red radiation by green green house gases and slightly by water vapors in atmosphere. These gases prevent heat from escaping to outer space, so are functionally comparable to glass panel of green house. Thus, this heating effect is referred to as green house effect. Carbon dioxide is a green house gas so increased amount of this gas in the atmosphere will result in increased atmospheric temperature and global warming.
2. Three sources of atmospheric carbon dioxide are:
- Volcanic eruption
- Respiration by plants and animals
- Decomposition of organic substance.
Explanation:
- <u>Overall rise in temperature </u>of the Earth due to excessive amount of green house gases in atmosphere that trap heat radiating from Earth's surface is called Global warming.
- Global warming can cause melting of ice caps, alteration of seasons, destruction of forest and increase in deserts.
- Green house gases include carbon dioxide, methane, ozone, nitrous oxide, and nitrogen dioxide etc.
- Among all these gases Carbon dioxide is the major component that is responsible for global warming.
- Carbon dioxide is added to the atmosphere by burning of fossil fuels, volcanic eruption and respiration. But Burning of fossil fuels itself adds about 18 X 10¹² tonnes of CO₂ anually.
- Global warming has become a major environmental concern now and needs to be controlled immediately.
Answer:
According to the diagram and the interaction of the structures to express information in the cell, it is true that:
- Molecule B can be used to produce molecule A.
- Molecule A can be used to produce molecule C.
Explanation:
Molecule A is a double stranded DNA, molecule B is a strand of RNA and molecule C is an amino acid encoded by a codon.
The DNA is capable of splitting and from one strand producing the messenger RNA, in the process of transcription.
Messenger RNA contains a sequence of bases, and the set of 3 bases of RNA form a triplet or codon. A specific amino acid can be formed from a codon. This process is called translation.
The way in which molecules A, B and C interact is through the processes of transcription and translation, making it possible to use genetic information for protein synthesis.
The other options are not possible because:
- <em>Only DNA can replicate, RNA needs the transcription to be synthesized.
</em>
- <em>Molecule B and C do not interact so that the amino acids are together, but this depends on the sequence of bases in the RNA.</em>
The rate-limiting step for the secretion of secretory proteins or the appearance at the plasma membrane for membrane protein is generally thought to be the rate of exit from the ER. Biosynthesis in or at the ER, including folding, modifications, and assembly, hence is the most crucial step for efficient secretion.
It is most likely P, I'm not 100% certain though
