Staar Reporting Category 2 Genetics Quiz

A gene is the basic unit of heredity that carries the information required for trait development. Chromosomes contain many genes, and nucleotides are the building blocks of DNA. Thus, genes are directly responsible for transmitting hereditary information.

DNA has a double helix structure, a discovery that was pivotal in understanding its function. This twisted ladder shape provides stability and assists in replication. Other shapes listed do not reflect the actual structure of DNA.

Transcription is the process where a segment of DNA is copied into mRNA. This mRNA then conveys genetic information needed for protein synthesis during translation. The other processes represent different biological functions.

DNA is made up of nucleotides, which consist of a sugar, a phosphate group, and a nitrogenous base. Amino acids are the building blocks of proteins, while monosaccharides and fatty acids are related to carbohydrates and lipids respectively. Thus, nucleotides are the correct building blocks of DNA.

Watson and Crick are famously credited with elucidating the double helix structure of DNA. Their groundbreaking work laid the foundation for modern molecular biology and genetics. Although the other scientists made significant contributions to science, they were not responsible for this discovery.

DNA polymerase is the enzyme that synthesizes new DNA strands by adding nucleotides during replication. RNA polymerase, on the other hand, is responsible for synthesizing RNA from a DNA template. DNA ligase and helicase play different roles in DNA processing, making DNA polymerase the correct choice.

DNA replication is the process by which a cell makes a complete copy of its DNA. This ensures that each daughter cell receives an identical set of genetic instructions. The other processes are involved in gene expression or alterations in the DNA sequence.

A mutation is defined as any change in the DNA sequence, which can affect gene function and lead to genetic diversity. It is not a normal process of RNA formation, protein synthesis, or cell division. These other processes describe different aspects of cellular function.

Translation is the process during which ribosomes read mRNA and assemble amino acids in the correct order to form a protein. Transcription is used to create mRNA from DNA, and replication is the copying of DNA. Mutation is a change in the genetic code, making translation the correct answer.

tRNA's main function is to transport specific amino acids to the ribosome during the process of translation. It reads the codons on the mRNA and ensures that the correct amino acid is added to the growing polypeptide chain. The other options describe roles performed by different components in the cell.

Genes contain the information necessary to build proteins through the processes of transcription and translation. The other options reverse the direction of information flow or are simply incorrect. Thus, genes serve as blueprints for proteins.

The phenotype refers to an organism's observable characteristics, such as physical appearance and behavior. Genotype describes the genetic makeup, karyotype details the chromosome set, and genome encompasses all the genetic material. Therefore, phenotype is the correct term.

Being heterozygous means that an organism has two different alleles for a particular gene. In contrast, homozygous individuals have two identical alleles. This genetic variation can lead to differences in trait expression.

Gel electrophoresis is a laboratory method used to separate DNA fragments by size through the application of an electric field. The other techniques are used for amplifying, determining the sequence, or analyzing gene expression. Therefore, gel electrophoresis is the correct technique for separation.

Crossing over is the process during meiosis in which homologous chromosomes exchange segments of genetic material, increasing genetic diversity. The other processes do not describe the exchange of genetic material during meiosis. This makes crossing over the correct answer.

Epigenetics involves heritable changes in gene expression that occur without alterations to the DNA sequence. These changes can be brought about by mechanisms such as DNA methylation and histone modification. The other options either involve changes in the DNA sequence or describe different phenomena.

Telomeres are repetitive nucleotide sequences that protect the ends of chromosomes from degradation and fusion with neighboring chromosomes. Centromeres are involved in the attachment of spindle fibers during cell division, while exons and introns are parts of genes. Thus, telomeres are key to maintaining chromosomal integrity.

Introns are removed from pre-mRNA through a process called RNA splicing, which is facilitated by a complex known as the spliceosome. This step is essential for producing a mature mRNA that can be translated into protein. The other listed processes do not involve the removal of introns.

Incomplete dominance is observed when the heterozygous phenotype is an intermediate blend of the two homozygous phenotypes. Codominance, multiple allelism, and polygenic inheritance describe different patterns of genetic expression. Hence, incomplete dominance accurately describes a blended phenotype.

Insertion or deletion mutations that are not in multiples of three nucleotides can shift the reading frame, altering the entire downstream amino acid sequence. This frameshift mutation can drastically change protein structure and function. Other mutations like point, silent, or missense mutations typically do not result in a reading frame shift.