DNA/RNA Review Quiz

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.

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.

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

correct answer: RNA does but DNA contains thymine

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

correct answer: Chromatin

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.

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".

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.

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.

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.