Answer:
The type of mutation that occurs when in the DNA strand there is a change from guanine to cytosine is a nonsense mutation, since the triplet that should encode the amino acid encodes a stop codon and the protein cannot be completely synthesized.
Explanation:
The nonsense mutation consists of a change in one of the bases of the stranded DNA, which is transcribed into an altered mRNA, producing a stop codon, instead of an amino acid.
In the table it is observed that the CCA codon is a stop codon that cuts off the protein synthesis prematurely, leaving it incomplete and probably non-functional.
Sometimes this type of mutation can alter the sequence of amino acids but the protein may be complete enough to partially fulfill its function.
1. Answer: A
Explanation: For a cell to form proteins, the specific types of proteins are coded for by the genes in DNA (found in the chromosomes of the nucleus). To produce proteins, the genes are first transcribed by RNA polymerase to form messenger-RNA. The mRNA is then translated into proteins by ribosomes in the cytoplasm of the cell.
2. Answer: B
Explanation: Translation of genes into proteins is dependent on the sequence of nucleotides. They are translated in sequences of 3 nucleotides known as codons. Therefore adding a nucleotide on a piece of DNA causes what is referred to as a frame-shift mutation. The 3 sequences (of codons) is interrupted and shifted by one nucleotide. Therefore, the codons change and the amino acids translated will also change.
3. Answer: A
Expanation: Producers are significant in a food chain because they incorporate the energy of the sun into the food chain. This is why they are at the base of the food chain and have the largest biomass. They are consumed by primary consumers which are consumed by secondary consumers which are consumed by tertiary consumers and so on.
4. Answer: D
Explanation: Plants are consumed by herbivores. Therefore, a decrease in plant population due to drought was resulted to decrease in herbivore population. This is due to stiff competition by the herbivores for the scarce plant population. Carnivores consume herbivores. Due to a decrease in the herbivore population, then the carnivore population would also decrease.
5. Answer: A
Explanation: Burning of fossil fuels emits carbon dioxide gas which is a greenhouse gas. Greenhouse gas traps infrared wavelength of lights hence warming up the atmosphere, causing global warming. Reduction in use of fossil fuels will hence alleviate an increase in global temperature hence protect coral in the oceans from bleaching.
False. I don't know how to explain it but they don't classify as living.
The hawk would feed on secondary consumers
