1.
Which of these results when one nitrogenous base replaces another in a segment of genetic material?
Correct Answer
B. A mutation
Explanation
When one nitrogenous base replaces another in a segment of genetic material, it results in a mutation. A mutation refers to a permanent alteration in the DNA sequence, which can lead to changes in the structure, function, or regulation of genes. These changes can have various effects, including the development of new traits, genetic disorders, or even no noticeable impact. Mutations are an essential driving force for evolution as they introduce genetic diversity into populations.
2.
Scientists can insert and remove nucleotides from a DNA strand. Which of these identifies this process?
Correct Answer
B. Gene splicing
Explanation
Gene splicing is the process of inserting or removing nucleotides from a DNA strand. This process allows scientists to manipulate the genetic material and create new combinations of genes. Base pairing refers to the specific pairing of nucleotides in DNA replication, DNA synthesis refers to the process of creating a new DNA strand, and DNA transcription refers to the process of creating an RNA molecule from a DNA template. Therefore, gene splicing is the most appropriate identification for the process of inserting and removing nucleotides from a DNA strand.
3.
A scientist cloned a goat. Which of these is a true statement about the cloned goat?
Correct Answer
C. It has genes that are identical to the original goat.
Explanation
The correct answer is that the cloned goat has genes that are identical to the original goat. Cloning involves creating an organism that is genetically identical to another organism. In this case, the scientist has successfully created a goat that has the exact same genes as the original goat. This means that the cloned goat will have the same traits and characteristics as the original goat.
4.
Which of these is used to "cut" DNA?
Correct Answer
A. Restriction enzymes
Explanation
Restriction enzymes are used to "cut" DNA. These enzymes recognize specific sequences of DNA and cut the DNA at those sites, creating fragments. This process is important in genetic engineering and DNA analysis, as it allows scientists to manipulate and study specific sections of DNA. Gel electrophoresis is a technique used to separate DNA fragments based on their size, nucleotides are the building blocks of DNA, and amino acids are the building blocks of proteins, none of which directly "cut" DNA.
5.
In the laboratory, scientists remove the gene for insulin from human chromosomes. They insert the gene into the DNA of bacteria. This causes the bacteria to produce human insulin. The insulin is used to treat diabetes in humans. This is an example of ________.
Correct Answer
C. Genetic engineering
Explanation
This scenario describes the process of genetic engineering, where scientists manipulate the DNA of organisms to produce desired traits or substances. In this case, they remove the gene for insulin from human chromosomes and insert it into the DNA of bacteria, causing the bacteria to produce human insulin. This technique is commonly used to produce insulin for the treatment of diabetes in humans.
6.
Which of these describes a mutation that can be inherited?
Correct Answer
C. A nitrogen base substitution in a gamete cell
Explanation
A nitrogen base substitution in a gamete cell describes a mutation that can be inherited because gametes are reproductive cells that are involved in the formation of offspring. If a mutation occurs in a gamete cell, it can be passed on to the next generation during reproduction, resulting in the mutation being inherited by the offspring.
7.
A rare disorder is caused by changes in a gene. Parents of individuals with the disorder have only normal copies of this gene.
Which of these most likely causes this disorder?
Correct Answer
C. Mutation
Explanation
A mutation is the most likely cause of this disorder because it is stated that the disorder is caused by changes in a gene. A mutation refers to a change in the DNA sequence of a gene, which can lead to the development of genetic disorders. Since the parents have normal copies of the gene, it suggests that the mutation occurred spontaneously in the affected individual.
8.
A piece of DNA that codes for a certin protein or trait is known as a __________.
Correct Answer
B. Gene
Explanation
A piece of DNA that codes for a certain protein or trait is known as a gene. Genes are the basic units of heredity and contain the instructions for building and maintaining an organism. They determine the characteristics and traits that an organism will have. Genes are responsible for the transmission of genetic information from one generation to the next and play a crucial role in the development and functioning of living organisms.
9.
Which of the two pairs are both examples of organisms with the exact same DNA?
Correct Answer
C. Clones - identical twins
Explanation
Clones and identical twins are both examples of organisms with the exact same DNA. Clones are organisms that are genetically identical to their parent, as they are produced through asexual reproduction. Identical twins, on the other hand, are formed when a single fertilized egg splits into two embryos, resulting in two individuals with the same DNA. Therefore, both clones and identical twins have identical genetic material.
10.
If a gene from one organism is inserted into a second different type of organism, what is the most likely result?
Correct Answer
B. The second organism will develop a new trait
Explanation
When a gene from one organism is inserted into a second different type of organism, it is likely that the second organism will develop a new trait. This is because the inserted gene carries instructions for a specific characteristic or function, which can be expressed in the second organism and result in the development of a new trait.
11.
When techniques of genetic engineering are used to put together dna sequences from two different sources, the result is known as _______________.
Correct Answer
A. Recombinant DNA
Explanation
When techniques of genetic engineering are used to put together DNA sequences from two different sources, the result is known as recombinant DNA. This process involves the insertion of specific genes or DNA segments into a host organism's genome, resulting in a modified organism that expresses the desired traits or produces specific proteins. Recombinant DNA technology has revolutionized various fields such as medicine, agriculture, and industry, allowing scientists to manipulate and combine DNA sequences to create new genetic combinations with desired characteristics.
12.
Which of the following is not a true statement about transgenic foods?
Correct Answer
B. Transgenic foods make humans develop new traits
Explanation
Transgenic foods do not make humans develop new traits. Transgenic foods are genetically modified organisms (GMOs) that contain new traits compared to the original foods, as they are made through genetic engineering. However, consuming transgenic foods does not result in humans developing new traits. The other statements, such as transgenic foods containing new traits and being made through genetic engineering, are true. Additionally, transgenic foods are currently being sold in supermarkets.