1.
What does DNA stand for?
Correct Answer
C. Dioxyribosenucleic acid
Explanation
DNA stands for Dioxyribosenucleic acid. This is the correct answer because DNA is a molecule that contains the genetic instructions for the development and functioning of all known living organisms. It is composed of two strands of nucleotides, each containing a sugar molecule called deoxyribose, a phosphate group, and one of four nitrogenous bases (adenine, thymine, cytosine, or guanine). The presence of two deoxyribose molecules in DNA gives it the name Dioxyribosenucleic acid.
2.
What are the building blocks of DNA?
Correct Answer
B. Nucleotides
Explanation
Nucleotides are the building blocks of DNA. DNA is made up of a long chain of nucleotides, which are composed of a sugar molecule, a phosphate group, and a nitrogenous base. The sequence of these nucleotides forms the genetic code that determines the characteristics and functions of an organism. Genes, amino acids, and ribosomes are all important components in the process of protein synthesis, but they are not the basic units that make up DNA.
3.
Which of the following nucleotides bonds with cytosine?
Correct Answer
A. Guanine only
Explanation
Guanine is the nucleotide that bonds with cytosine. This is because guanine and cytosine form a complementary base pair in DNA. The bonding between guanine and cytosine is known as a hydrogen bond, which helps to stabilize the DNA double helix structure. Adenine only bonds with thymine, forming another complementary base pair. Therefore, the correct answer is guanine only.
4.
For what reason is DNA replicated within a cell?
Correct Answer
D. To provide new cells with a complete and identical copy of genetic material.
Explanation
DNA is replicated within a cell to provide new cells with a complete and identical copy of genetic material. This ensures that each new cell receives all the necessary genetic information to perform its functions and maintain the characteristics of the organism. Replication is essential for growth, development, and the replacement of damaged or old cells. It allows for the transmission of genetic traits from one generation to the next, ensuring the continuity of the species.
5.
If one side of the DNA molecule reads ATGCCGT, what would the complementary side read?
Correct Answer
C. TACGGCA
Explanation
The DNA molecule consists of two strands that are complementary to each other. In DNA, adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C). Therefore, if one side of the DNA molecule reads ATGCCGT, the complementary side would read TACGGCA. This is because A pairs with T, T pairs with A, G pairs with C, and C pairs with G.
6.
Which is the best meaning for the term transcription?
Correct Answer
C. Changing from one language to another
Explanation
Transcription refers to the process of converting spoken language or audio recordings into written form. This involves accurately representing the words and sounds of one language into another language, making it the best meaning for the term "transcription".
7.
What did the original DNA that produced an mRNA strand with a sequence of AGUACA look like?
Correct Answer
D. TCATGT
Explanation
The original DNA that produced an mRNA strand with a sequence of AGUACA would have the complementary sequence TCATGT. In DNA, adenine (A) pairs with thymine (T) and guanine (G) pairs with cytosine (C). Therefore, the original DNA sequence would have T instead of A, C instead of G, G instead of C, T instead of A, G instead of C, and T instead of A.
8.
Transcription is the process of DNA acting as a template for creating a mRNA molecule. Where does this occur?
Correct Answer
C. In the nucleus
Explanation
Transcription occurs in the nucleus. This is where the DNA is located, and it acts as a template for creating mRNA molecules. The process of transcription involves the enzyme RNA polymerase binding to the DNA and synthesizing a complementary mRNA strand. The mRNA molecule then carries the genetic information from the nucleus to the ribosomes in the cytoplasm, where translation takes place to produce proteins.
9.
The sequence of mRNA is AGUACA. What is the sequence of tRNA?
Correct Answer
A. UCAUGU
Explanation
The sequence of tRNA is UCAUGU because tRNA molecules have anticodons that are complementary to the codons on mRNA. In this case, the codon AGU on the mRNA corresponds to the anticodon UCA on the tRNA. The remaining codons and anticodons in the answer choices do not match the given mRNA sequence.
10.
A strand of DNA with the sequence ACTTG serves as a template to form a corresponding sequence with a TGAAC pattern. During which process would this activity occur?
Correct Answer
A. Replication
Explanation
During replication, the DNA molecule is copied to form an identical strand. The template strand, in this case, with the sequence ACTTG, would be used to create a complementary strand with the pattern TGAAC. This process occurs during the S phase of the cell cycle, where the DNA is replicated before cell division. Transcription, translation, and protein synthesis involve the conversion of DNA information into RNA and then into proteins, which is not the case in this scenario. Therefore, replication is the correct process for this activity to occur.
11.
RNA is a double stranded structure.
Correct Answer
B. False
Explanation
correct answer: Single stranded- looks like 1/2 of a zipper
12.
RNA and DNA contain a nitrogenous base called uracil.
Correct Answer
B. False
Explanation
correct answer: RNA does but DNA contains thymine
13.
DNA is a strand of genetic material that carries the code for:
Correct Answer
B. Eye color
Explanation
DNA carries the code for eye color. Eye color is determined by the combination of genes inherited from both parents, and these genes are encoded in the DNA. The specific variations in the DNA sequence determine the production of pigments that give rise to different eye colors. Therefore, DNA plays a crucial role in determining an individual's eye color.
14.
What are the 3 parts of a nucleotide?
Correct Answer
B. Simple sugar, a pHospHate group, nitrogenous base
Explanation
A nucleotide is composed of three parts: a simple sugar, a phosphate group, and a nitrogenous base. The simple sugar provides the backbone of the nucleotide, the phosphate group is attached to the sugar, and the nitrogenous base is connected to the sugar as well. These three components together form the basic building blocks of nucleic acids, such as DNA and RNA.
15.
Which organism does not contain DNA?
Correct Answer
A. Bacteria
Explanation
Bacteria do contain DNA. Bacteria are single-celled organisms that have a simple structure and lack a nucleus. However, they still have DNA, which is organized in a circular chromosome within the cytoplasm. This DNA contains the genetic information necessary for the bacteria to carry out their functions and reproduce. Therefore, the statement that bacteria do not contain DNA is incorrect.
16.
DNA takes on the shape of a double helix.
Correct Answer
A. True
Explanation
DNA takes on the shape of a double helix because it consists of two strands of nucleotides that are twisted together in a spiral formation. The structure of the double helix allows for the efficient packing of genetic information and provides stability to the DNA molecule. The two strands are held together by hydrogen bonds between complementary base pairs (adenine with thymine, and guanine with cytosine), forming the characteristic twisted ladder shape. This structure is essential for DNA replication and transcription, as it allows for the accurate copying and reading of genetic information.
17.
The nucleus contains all of the organism's DNA in long, tangled strings called organelles.
Correct Answer
B. False
Explanation
correct answer: Chromatin
18.
What happens when DNA replicates?
Correct Answer
D. Two molecules form with one original strand and one new strand
Explanation
When DNA replicates, two molecules are formed with one original strand and one new strand. This process is known as semi-conservative replication, where each new DNA molecule contains one strand from the original DNA molecule and one newly synthesized complementary strand. This ensures that the genetic information is accurately passed on to the daughter cells during cell division.
19.
The closer the relationship between two organisms, the more similar their DNA nucleotide sequence will be.
Correct Answer
A. True
Explanation
The statement is true because DNA nucleotide sequences are used to determine the genetic relatedness between organisms. As organisms evolve and diverge from a common ancestor, their DNA sequences accumulate changes over time. Therefore, organisms that are closely related will have more similar DNA nucleotide sequences compared to those that are distantly related. This similarity in DNA sequences reflects the shared ancestry and evolutionary history between organisms.
20.
In a chain of nucleotides, the sugar of one nucleotide would join to the:
Correct Answer
A. pHospHate group of the next nucleotide
Explanation
In a chain of nucleotides, the sugar of one nucleotide joins to the phosphate group of the next nucleotide. This linkage forms the backbone of the DNA molecule, with the phosphate group connecting the sugars together. The nitrogenous base of each nucleotide is attached to the sugar molecule, and the hydrogen bonds form between the nitrogenous bases of complementary nucleotides on the opposite strands of DNA. However, the sugar-phosphate backbone provides the structural stability and support for the DNA molecule.