DNA/RNA Review Quiz

1. DNA takes on the shape of a double helix.

True

False

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.

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.

2. What does DNA stand for?

Dyribose acid

Digestive nucleic acid

Dioxyribosenucleic acid

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.

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.

3. RNA is a double stranded structure.

True

False

correct answer: Single stranded- looks like 1/2 of a zipper

Explanation

correct answer: Single stranded- looks like 1/2 of a zipper

4. RNA and DNA contain a nitrogenous base called uracil.

True

False

correct answer: RNA does but DNA contains thymine

Explanation

correct answer: RNA does but DNA contains thymine

5. For what reason is DNA replicated within a cell?

To add more traits to a living organism as it ages.

To fill increased space within the nucleus of a growing cell.

To change the traits of a living organism to meet its needs in a new environment.

To provide new cells with a complete and identical copy of genetic material.

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.

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.

6. What are the building blocks of DNA?

Genes

Nucleotides

Amino acids

Ribosomes

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.

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.

7. Which of the following nucleotides bonds with cytosine?

Guanine only

Cytosine and guanine

Adenine only

Adenine and thymine

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.

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.

8. If one side of the DNA molecule reads ATGCCGT, what would the complementary side read?

TACGCCU

UACGGCA

TACGGCA

TAGCCGA

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.

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.

9. What are the 3 parts of a nucleotide?

Fat, carbohydrate, a phosphate group

Simple sugar, a phosphate group, nitrogenous base

Lipid, a phosphate group, nitrogenous base

Carbohydrate, nitrogenous base, a phosphate group

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.

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.

10. The closer the relationship between two organisms, the more similar their DNA nucleotide sequence will be.

True

False

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.

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.

11. Transcription is the process of DNA acting as a template for creating a mRNA molecule. Where does this occur?

In the cell membrane

In the cytoplasm

In the nucleus

In the ribosomes

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.

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.

12. The sequence of mRNA is AGUACA. What is the sequence of tRNA?

UCAUGU

AGTACA

AGUACA

TCATGT

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.

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.

13. What happens when DNA replicates?

One molecule forms with two original strands

Two molecules form with two new strands

Two molecules form with two original strands

Two molecules form with one original strand and one new strand

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.

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.

14. The nucleus contains all of the organism's DNA in long, tangled strings called organelles.

True

False

correct answer: Chromatin

Explanation

correct answer: Chromatin

15. What did the original DNA that produced an mRNA strand with a sequence of AGUACA look like?

UCAUGU

ACTACA

AGUACA

TCATGT

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.

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.

16. In a chain of nucleotides, the sugar of one nucleotide would join to the:

Phosphate group of the next nucleotide

Sugar of the next nucleotide

Nitrogenous base of the next nucleotide

Next hydrogen bond

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.

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.

17. Which is the best meaning for the term transcription?

Joining together

Writing out

Changing from one language to another

Erasing

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".

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".

18. Which organism does not contain DNA?

Bacteria

Animals

Plants

Fungi

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.

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.

19. 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?

Replication

Transcription

Translation

Protein synthesis

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.

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.

20. DNA is a strand of genetic material that carries the code for:

Proteins

Eye color

Enzymes

Carbohydrates

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.

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.