Exam 5 Review

A polymer is a large molecule or macromolecule consisting of many repeated subunits. The correct answer describes the specific type of polymer known as a polynucleotide, which consists of nucleotides covalently bonded together.

The backbone of DNA is made up of alternating phosphates and the 5-carbon sugar molecules, forming the structure of the double helix.

The correct answer describes the specific structure of DNA, while the incorrect answers provide unrelated or incorrect definitions.

Purines are the two-ring nitrogenous bases found in DNA. Adenine and Guanine are the purines, while Cytosine, Thymine, and Uracil are pyrimidines.

Pyrimidines are one of the two types of nitrogenous bases found in DNA, along with purines. Thymine and Cytosine are pyrimidines that have a single-ring structure compared to the double-ring structure of purines like Adenine and Guanine.

Hydrogen bonds in DNA play a crucial role in maintaining the overall structure of the molecule and ensuring complementary base pairing for accurate replication and transcription processes.

The four nitrogen bases that make up the structure of DNA are Adenosine (A), Cytosine (C), Thymine (T), and Guanine (G).

In DNA structure, adenine always pairs with thymine and guanine pairs with cytosine. Adenosine will never pair with guanine or cytosine, while cytosine will never pair with adenosine or thymine.

DNA and RNA have distinct characteristics related to sugar composition, nitrogenous bases, and the number of strands they possess. The distinctions lie in their fundamental structures and functions within cells.

Watson and Crick are credited with discovering the double helix structure of DNA in 1953. Mendel is known for his work in genetics with pea plants, while Darwin proposed the theory of evolution. Curie was a pioneering scientist in the field of radioactivity.

DNA polymerase is the enzyme that plays a crucial role in DNA replication by assembling new DNA strands.

During transcription, RNA polymerase is the enzyme responsible for constructing RNA by catalyzing the formation of phosphodiester bonds between ribonucleotides. DNA polymerase is involved in DNA replication, ligase is important for sealing nicks in DNA strands, and helicase is responsible for unwinding the DNA double helix.

Transcription is the first step in gene expression and involves the synthesis of mRNA from DNA. It takes place in the nucleus of eukaryotic cells. The incorrect answers provided describe different processes involving other molecules and locations, highlighting the importance of understanding the specific details of transcription.

Translation is the process of converting the genetic information encoded in mRNA into a sequence of amino acids, which is essential for protein synthesis. It involves mRNA as the template, rRNA (ribosomes) as the machinery, and tRNA carrying specific amino acids. Translation takes place in the cytoplasm where ribosomes are located.

Genotype refers to the specific genetic makeup of an organism, which is determined by the combination of alleles inherited from its parents.

A phenotype refers to the observable characteristics or traits of an organism resulting from the interaction between its genetic makeup (genotype) and the environment.

There are 20 standard amino acids that are commonly found in proteins, each with its own unique properties and functions in the body.

mRNA is specifically involved in genetic information transfer and protein synthesis, not in lipid molecules, carbohydrates, or structural proteins.

tRNA, or transfer RNA, plays a crucial role in protein synthesis by binding to specific amino acids and conveying them to the ribosome during translation. It is not a type of DNA, protein, or enzyme.

rRNA, or ribosomal RNA, is a crucial component of ribosomes, which are protein-making factories within cells. It is the most abundant type of RNA and plays a key role in the synthesis of proteins.

Correct answer: Codons are specific sequences in mRNA, not in the cell nucleus, cytoplasm, or ribosomes. These sequences play a key role in protein synthesis.

Transcription is the process of making RNA from a DNA template. The three major stages are initiation (where RNA polymerase binds to the promoter region), elongation (where RNA is synthesized), and termination (where RNA polymerase detaches from the DNA template). The incorrect answers provide different or incorrect stages that are not part of the transcription process.

A promoter is a specific nucleotide sequence in DNA that plays a crucial role in initiating the process of transcription.

Peptide bonds are specific covalent bonds between amino acids in a polypeptide chain, not weak electrostatic interactions, hydrogen bonds, or ionic bonds.

Mutations are essential for genetic diversity which is a key component of evolution. While some mutations may have negative effects, others can be beneficial and drive the process of natural selection.

Gene expression refers to the process of turning the information encoded in a gene into a functional product, usually a protein. This process involves the transcription of DNA into RNA and the translation of RNA into protein.

A DNA microarray is a tool used to measure the expression levels of a large number of genes simultaneously.

Therapeutic cloning specifically refers to the cloning of human cells for therapeutic purposes, not plants, animals, or genetically modified organisms.