1.
DNA is a duoble stranded helix that is held together by...
Correct Answer
B. Hydrogen Bond
Explanation
DNA is a double-stranded helix that is held together by hydrogen bonds. Hydrogen bonds form between the nitrogenous bases of the two DNA strands. Specifically, adenine (A) forms two hydrogen bonds with thymine (T), while guanine (G) forms three hydrogen bonds with cytosine (C). These hydrogen bonds provide stability to the DNA molecule and allow for the separation of the two strands during replication and transcription processes. Covalent bonds and ionic bonds are not involved in holding the DNA strands together.
2.
What are the four base pairs used as a template model when DNA synthesis occurrs?
Correct Answer
B. Thymine, Cytosine, Guanine, Adenine
Explanation
The four base pairs used as a template model when DNA synthesis occurs are Thymine, Cytosine, Guanine, and Adenine.
3.
DNA + Protein=
Correct Answer
D. Chromosome
Explanation
DNA and protein are both components of a chromosome. A chromosome is a structure found in the nucleus of a cell that contains DNA wrapped around proteins called histones. The DNA in a chromosome carries genetic information, while the proteins provide structural support and help regulate gene expression. Therefore, the correct answer is chromosome.
4.
RNA is a...
Correct Answer
A. Single Strand
Explanation
RNA is a single strand because it is composed of a single chain of nucleotides. Unlike DNA, which is double-stranded, RNA does not have a complementary strand. It is formed by a process called transcription, where a single DNA strand is used as a template to synthesize a complementary RNA molecule. This single-stranded structure allows RNA to fold into various shapes and perform diverse functions in the cell, including protein synthesis, gene regulation, and catalysis.
5.
What is the purpose of the enzyme DNA ligase?
Correct Answer
C. Forms a bond and puts together segments
Explanation
DNA ligase is an enzyme responsible for forming a bond between DNA segments. It plays a crucial role in DNA replication and repair by joining the Okazaki fragments on the lagging strand during replication and sealing any nicks or gaps in the DNA backbone. This process ensures the continuity of the DNA strand and maintains the integrity of the genetic material. Therefore, the purpose of DNA ligase is to form a bond and put together segments of DNA.
6.
What is the purpose of the enzyme DNA polymerase?
Correct Answer
B. Adds new nucleotides
Explanation
The purpose of the enzyme DNA polymerase is to add new nucleotides to the growing DNA strand during replication. This enzyme is responsible for synthesizing a complementary strand of DNA using the existing template strand as a guide. It catalyzes the formation of phosphodiester bonds between the incoming nucleotides, resulting in the elongation of the DNA molecule. DNA polymerase plays a crucial role in DNA replication and ensures the accurate copying of genetic information.
7.
What is the purpose of the enzyme DNA helicase?
Correct Answer
B. Seperates the double helix into two seperate strands
Explanation
The purpose of the enzyme DNA helicase is to separate the double helix into two separate strands. This process is essential for DNA replication and transcription, as it allows the DNA strands to be accessed and used as templates for the synthesis of new DNA or RNA molecules. DNA helicase accomplishes this by breaking the hydrogen bonds between the base pairs, unwinding the double helix and creating two single strands that can be used for further processes in DNA metabolism.
8.
Match up the following... TAGCCATAC
Correct Answer
C. ATCGGTAG
Explanation
The given answer "ATCGGTAG" matches the sequence "TAGCCATAC" by pairing each nucleotide with its complementary base. In DNA, adenine (A) pairs with thymine (T) and cytosine (C) pairs with guanine (G). By pairing the bases in the given sequence, we get "ATCGGTAG", which matches the given answer.
9.
In RNA synthesis, Adenine pairs up with _____ instead of Thymine.
Correct Answer
C. Uracil
Explanation
In RNA synthesis, Adenine pairs up with Uracil instead of Thymine. This is because RNA uses Uracil as one of its four nucleotide bases, while DNA uses Thymine. Adenine and Uracil form a complementary base pair, allowing for the accurate replication and transcription of RNA molecules.
10.
Whats the main purpose in gene regulation?
Correct Answer
A. Conserve enegy
Explanation
The main purpose of gene regulation is to conserve energy. Gene regulation allows an organism to control the expression of its genes, ensuring that only necessary genes are activated at a given time. By conserving energy and resources, the organism can allocate them efficiently to other important cellular processes. This regulation helps maintain homeostasis and adapt to changing environments, optimizing energy usage for survival and growth.
11.
Gene mutatons occur when....
Correct Answer
D. Both B and C
Explanation
Gene mutations occur when the gene sequence changes shape or is cut off, and when the gene sequence removes or adds nucleotides. This means that both options B and C are correct.
12.
When mutation occurs but it does not change the protein its referred to as______ mutation.
Correct Answer
D. Silent
Explanation
Silent mutation refers to a type of mutation that occurs in the DNA sequence but does not result in a change in the corresponding protein. This means that even though the nucleotide sequence may be altered, the amino acid sequence remains the same, and therefore, the protein's function is unaffected. Silent mutations are often considered neutral since they do not cause any noticeable phenotypic changes.
13.
_______ ________ causes sever damage if it happens at the beginning of the sequence due to it changing the entire protein produced.
Correct Answer
B. Frameshift insertion
Explanation
Frameshift insertion causes severe damage if it happens at the beginning of the sequence because it changes the reading frame of the genetic code, resulting in a completely different protein being produced. This type of mutation occurs when an extra nucleotide is inserted into the DNA sequence, shifting the triplet codon reading frame. As a result, all subsequent codons are read incorrectly, leading to a non-functional or truncated protein. This can have significant effects on the structure and function of the protein, often resulting in detrimental consequences for the organism.
14.
When this type of mutation occurs it changes the protein produced and is most likely not functional.
Correct Answer
C. Missense
Explanation
A missense mutation is a type of mutation that occurs when a single nucleotide change in the DNA sequence results in a different amino acid being incorporated into the protein. This change in the protein's composition can alter its structure and function, potentially leading to a loss of function or a malfunctioning protein. Therefore, when a missense mutation occurs, it is most likely that the protein produced will not be functional.
15.
Nonsense mutation stops the _____ from producing the protein.
Correct Answer
D. Codon
Explanation
A nonsense mutation is a type of genetic mutation that introduces a premature stop codon in the DNA sequence. This stop codon signals the end of protein synthesis and prevents the production of a functional protein. Therefore, the correct answer is "codon" as it is the specific sequence of three nucleotides that determines the incorporation of a specific amino acid during protein synthesis.