1.
The term that describes a mistake in the separation of homologous chromosomes during anaphase 1 is
Correct Answer
E. Nondisjunction
Explanation
Nondisjunction is the term that describes a mistake in the separation of homologous chromosomes during anaphase 1. This occurs when the chromosomes fail to separate properly, leading to an unequal distribution of genetic material in the resulting cells. Nondisjunction can result in genetic disorders and abnormalities, as the cells may end up with an abnormal number of chromosomes.
2.
If one side of a DNA strand has nucleotide sequence ATTGCAGTCTGTTT, the other side of the DNA strand will have the nucleotide sequence __________________________.(type your answer in CAPS)
Correct Answer
TAACGTCTGACAAA
Explanation
The other side of a DNA strand will have the complementary nucleotide sequence. In DNA, adenine (A) always pairs with thymine (T), and guanine (G) always pairs with cytosine (C). Therefore, the complementary sequence to ATTGCAGTCTGTTT would be TAACGTCTGACAAA.
3.
The molecule that is used as a copy of the protein encoding DNA strand during protein synthesis is ____________________.
Correct Answer
mRNA
MRNA
mrna
Explanation
mRNA, MRNA, and mrna all refer to messenger RNA, which is the molecule used as a copy of the protein encoding DNA strand during protein synthesis. mRNA carries the genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm, where it serves as a template for protein synthesis. The variations in capitalization (mRNA, MRNA, mrna) do not affect the meaning or function of the molecule.
4.
If one side of a DNA strand has nucleotide sequence ATTGCAGTCTGTTT, the resulting mRNA that is made will have the nucleotide sequence
__________________________.(type your answer in CAPS)
Correct Answer
UAACGUCUGACAAA
Explanation
The mRNA sequence is the complementary sequence to the DNA sequence. In DNA, adenine (A) pairs with thymine (T) and cytosine (C) pairs with guanine (G). Therefore, in the given DNA sequence ATTGCAGTCTGTTT, the complementary mRNA sequence will have the nucleotide sequence UAACGUCUGACAAA.
5.
Analyze the following pedigree:Is it possible that the genetic disorder represented by the purple shaded individuals is autosomal dominant?
Correct Answer
B. No, it is not possible
Explanation
The pedigree does not show a pattern where the disorder is passed down from one affected generation to the next. In an autosomal dominant disorder, at least one parent must have the disorder for their offspring to have it. However, in this pedigree, there are affected individuals who have unaffected parents, which suggests that the disorder is not autosomal dominant. Therefore, it is not possible for the genetic disorder represented by the purple shaded individuals to be autosomal dominant based on the information given.
6.
Analyze the following pedigree:If the genetic disorder is X-linked recessive, and individual 2 (generation I) is homozygous dominant for the trait, what is the % chance that individual 3 (generation II) would have been born with this disorder?
Correct Answer
A. 0%
Explanation
Individual 2 is homozygous dominant for the X-linked recessive disorder. Since the disorder is X-linked recessive, it means that the gene for the disorder is located on the X chromosome. Since individual 2 is homozygous dominant, it means that they have two dominant alleles on their X chromosome and do not carry the gene for the disorder. Therefore, individual 3, who inherits one X chromosome from individual 2, would not have been born with the disorder. The chance is 0%.
7.
Analyze the following pedigree:
If the genetic disorder is X-linked recessive, and individual 2 (generation (I) is
homozygous dominant for the trait, what is the % chance that individual 5
(generation II) would have been born with this disorder?
Correct Answer
A. 0%
Explanation
Since the genetic disorder is X-linked recessive, it is passed on from a carrier mother to her sons. Individual 2 is homozygous dominant, which means they do not carry the recessive allele for the disorder. Therefore, individual 5 cannot inherit the disorder from individual 2. Hence, the chance that individual 5 would have been born with this disorder is 0%.
8.
Analyze the following pedigree:
If the genetic disorder is X-linked recessive, what is individual 2's (generation II) genotype?
Correct Answer
B. Heterozygous
Explanation
Based on the given information, individual 2's genotype can be determined as heterozygous. This is because if the genetic disorder is X-linked recessive, it means that the disorder is carried on the X chromosome. Since individual 2 is unaffected by the disorder, it means that they must have inherited a dominant allele from one parent and a recessive allele from the other parent. Therefore, their genotype is heterozygous.
9.
Analyze the following pedigree:
Is it possible that the genetic disorder represented by the purple
shaded individuals is X-Linked recessive?
Correct Answer
B. No, it is not possible
Explanation
Based on the given pedigree, it is not possible for the genetic disorder represented by the purple shaded individuals to be X-Linked recessive. This is because X-Linked recessive disorders typically affect males more than females, and the pedigree shows that both males and females are affected in equal numbers. Additionally, there is no pattern of the disorder skipping generations, which is commonly observed in X-Linked recessive disorders. Therefore, the disorder is unlikely to be X-Linked recessive.
10.
The three nucleotide "chunk" on a molecule of mRNA that is "read" by the active site on a ribosome is referred to as a(n)
Correct Answer
C. Codon
Explanation
A codon is a three-nucleotide sequence on mRNA that corresponds to a specific amino acid or a stop signal during protein synthesis. The ribosome's active site "reads" the codon and matches it with the appropriate transfer RNA (tRNA) molecule carrying the corresponding amino acid. This process ensures that the correct sequence of amino acids is incorporated into the growing protein chain. Therefore, the correct answer is codon.
11.
The process of creating a molecule of mRNA is known as
Correct Answer
B. Translation
Explanation
The process of creating a molecule of mRNA is known as translation. This is the process where the genetic information from DNA is used to synthesize proteins. During translation, the mRNA molecule is read by ribosomes, and amino acids are brought in by transfer RNA (tRNA) molecules to form a polypeptide chain, which eventually folds into a functional protein. Transcription, on the other hand, is the process of creating an mRNA molecule from a DNA template. Replication refers to the process of copying DNA, and splicing is the process of removing introns from pre-mRNA molecules.
12.
Translation occurs
Correct Answer
A. In the cell nucleus
Explanation
Translation is the process by which proteins are synthesized using the information encoded in mRNA. This process takes place in the cell nucleus, where the DNA is transcribed into mRNA. The mRNA then travels to the cell cytoplasm, where it is translated by ribosomes to produce proteins. Therefore, the correct answer is "in the cell nucleus" as this is where the initial steps of translation occur.
13.
Transcription occurs
Correct Answer
B. In the cell cytoplasm
Explanation
Transcription is the process by which genetic information in DNA is copied into RNA. It occurs in the cell cytoplasm, which is the region outside the cell nucleus. The cell nucleus contains the DNA, but transcription takes place in the cytoplasm where the RNA polymerase enzyme can access the DNA. This allows the RNA to be synthesized and then used for various cellular processes. Transcription is not limited to reproductive or fertilized egg cells; it occurs in all types of cells.
14.
Down's Syndrome is also referred to as trisomy 21 because
Correct Answer
A. It is caused by the inheritance of three copies of chromosome #21
Explanation
Down's Syndrome, also known as trisomy 21, is caused by the inheritance of three copies of chromosome #21. In individuals with Down's Syndrome, instead of the usual two copies of chromosome #21, there is an extra copy, resulting in a total of three copies. This extra genetic material disrupts the normal development and causes the characteristic physical and intellectual disabilities associated with the syndrome.
15.
In protein synthesis, molecules of tRNA
Correct Answer
D. Carry specific amino acids to the ribosomes during transcription
Explanation
During protein synthesis, molecules of tRNA carry specific amino acids to the ribosomes. This process occurs during translation, not transcription. Transcription is the process of creating an mRNA molecule from a DNA template, while translation is the process of using the mRNA molecule to synthesize a protein. tRNA molecules have an anticodon that is complementary to the codon on the mRNA, allowing them to bring the correct amino acid to the ribosome. Therefore, the correct answer is that tRNA carries specific amino acids to the ribosomes during translation.