1. Answer;
There is not enough information to answer;
Explanation;
- According to Chargaff’s rule the concentration for each base in a base pair is always equal to its mate. This means that the concentration of adenine will always equal the concentration of its pair thymine, and the concentrations of guanine and cytosine will be equal, too.
- Therefore, the concentration of a given base in a DNA sample can be determined such that if a sample has 20% thymine, then it’s automatic that it has 20% Adenine. Also the percentage of Adenine can be determined when given the concentration of guanine or cytosine, since all the four bases together must be equal to 100%.
2. Answer;
B enzymes unwind the DNA molecule in two strands
Explanation;
- DNA replication is the process by which DNA molecule duplicates itself to produce two DNA molecules. The process occurs before the cell division begins, so as to ensure that each new cell receives the correct number of chromosomes.
- The process of DNA replication is catalyzed by DNA polymerase enzyme. It is a vital process for cellular growth, repair and reproduction in organisms. The process occurs in the S phase of interphase among plants and animal cells.
- The process begins with formation of replication fork, where an enzyme DNA helicase unwinds the DNA molecule into two strands forming a Y shape known as replication fork.
3. Answer;
A DNA is transcribed to RNA then translated into proteins
Explanation;
- Central Dogma describes how the genetic information in the DNA sequence becomes the proteins that provide the structure and perform the essential chemical reactions of a living cell.
- The double stranded DNA molecules are transcribed by RNA polymerase molecules in conjunction with repressor and activator proteins into single stranded RNA molecules via a process called transcription. These RNA molecules interact with ribosomes and activated transfer RNAs to produce proteins via a process called translation. The four base code of the single stranded RNA molecule is translated into the amino acid sequence of a protein.
4. Answer;
D carry the code of DNA to ribosomes.
The function of RNA is to carry the code of DNA to ribosomes
Explanation;
- During the process of gene expression the double stranded DNA molecules are transcribed by RNA polymerase molecules in conjunction with repressor and activator proteins into single stranded RNA molecules via a process called transcription.
- The RNA molecules interact with ribosomes and activated transfer RNAs to produce proteins via a process called translation. The four base code of the single stranded RNA molecule is translated into the amino acid sequence of a protein.
5. Answer;
B to add complementary bases to the new DNA strand
Explanation;
- DNA polymerase is the enzyme that catalyzes the process of DNA replication. DNA replication is the process by which DNA molecule duplicates itself to produce two DNA molecules.
- DNA polymerase makes a DNA molecule from nucleotides which are the building blocks of DNA. There are several types of DNA polymerase which help in the synthesis of a new DNA molecule during the process of replication. DNA polymerase I; which takes the role of DNA repair and part of replication, DNA polymerase II, which undertakes the role of DNA repair and DNA polymerase III, which adds DNA nucleotides on to the 3’ primer.
6. Answer;
B mitosis and cell division
Explanation;
- DNA replication is the process by which DNA molecule duplicates itself to produce two DNA molecules. The process occurs before mitosis and cell division begins, so as to ensure that each new cell receives the correct number of chromosomes.
- The process of DNA replication is catalyzed by DNA polymerase enzyme. It is a vital process for cellular growth, repair and reproduction in organisms. The process occurs in the S phase of interphase among plants and animal cells.