Answer:
a. True
Explanation:
Ribosomes are ribonucleoprotein complexes composed of RNA and proteins, which have two main roles 1-decode the message of the messenger RNA (mRNA) molecule and the formation of peptide bonds in the protein. For this purpose, each triplet of nucleotide bases or 'codon' in the mRNA sequence is used to assemble specific amino acids in the nascent polypeptide chain. Although different, both prokaryotic ribosomes and eukaryotic ribosomes are composed of two subunits: one small subunit that decodes the mRNA into a specific amino acid chain, and one large subunit that forms the peptide bonds in the polypeptide chain. Each ribosomal subunit is in turn composed of ribosomal RNAs and proteins. These ribosomal RNAs act as scaffolds by combining with proteins that assemble into ribosomes (i.e., small and large ribosome subunits).
Carbon cycle, one of the most important elements that make up the structure of living things in an ecosystem carbon. Carbon is found in the structure of all organic compounds in living things.
Earth is important warehouses;
Atmospheric CO2In the waters of CO2 and HCO3-Land, usually coal, is the structure of the oil and limestone.<span>Photosynthesis by plants using airborne CO2 and O2 is converted to organic compounds. By participating in CO2 carbon all live in the structure of the building is used as a raw organic food energy and structure. In respiratory events again returned to the atmosphere as CO2. If a portion of the carbon is deposited on the ground layer mineral or dead plants and animals through the soil into the organic waste. Here are separated by saprophytes live or coal goes back into the atmosphere through the use of fossil fuels such as oil. However, excessive use of fossil fuels in the atmosphere the CO2 greenhouse effect climate change will bring about in the world, raises a few degrees increase and the consequent danger of melting glaciers at the poles of the temperature.</span><span />
Answer:
c. A bacterial cell that lacked receptors on its surface for that antibiotic
Explanation:
If the bacteria lacks the receptors on its surface meant for that antibiotic then it will be best defense for the survival of that bacteria. It is receptors which interact with the antibiotic so as to permit it inside the cell. Therefore, in the absence of receptors, it doesn't matter how much antibiotic is lying in the external environment of that bacteria, the antibiotic will not be able to enter the bacterial cell to kill it. Hence, the bacteria will be able to survive easily.
Answer:
they form long chain-like molecules.
Explanation:
they combine using covalent bonds, and give off water molecules.
Answer:
B) There is an increase in the number of giraffes with long necks in areas of Africa where low-growing trees have died
Explanation:
The directional selection is one of the ways of the natural selection in which the natural selection selects or favours the most extreme trait of the species and the extreme trait show higher fitness than the normal or average trait.
In the given question, the case of Giraffe necks shows directional selection as the normal length of the neck is not favoured by the environment but the extreme trait that is long neck is favoured by the environment and the selection shifted to that level.
Thus, Option-B is the correct answer.
