IB 204- Genetics Study Guide

Recessive traits are only visible in:
a. polypoid individual
b. Homozygous individual
c. Heterozygous individual
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Recessive traits are only visible in:
a. polypoid individual
b. Homozygous individual
c. Heterozygous individual
b.
Whose data provided the key piece of evidence that DNA is a helix leading to the discovery of the structure or DNA?
a. Francis Crick
b. Erwin Chargaff
c. Rosalind Franklin
c.
Which phenotype is not controlled by multiple genes interacting with each other and the environment?
a. Height
b. Depression
c. Lactose intolerant
c.
How genetically similar are humans (%)?
99.9%
What types of genetic difference are responsible for human genetic variation?
a. duplications
b. SNPs, duplications, and deletions
c. deletions
d. deletions and duplications
e. SNPs
b.
Individuals can be carriers of the Sickle Cell Trait, but not suffer from the disease. What type of treat is this an example of and how do carriers remain disease free?
SCA is a recessive disorder, individuals who are heterozygous for SC trait possess a functional copy of the gene. & so are able to produce functional hemoglobin.
Gene therapy for SCA involves removing the patient's bone marrow stem cells, deleting the BCL11A gene via CRISPR, and re-implanting the edited cells. How does deleting BCL11A lead to remission from symptoms?
Deleting BCL11A allows for production of gamma hemoglobin in adults which can replace the defective beta hemoglobin gene.
Retinoblastoma (RB) protein is an example of a tumor suppressor gene, this means that under normal conditions its role is to:

a. Prevent cell cycle division
b. Promote cell cycle division
c. Promote apoptosis
a.
A mutation in the as gene converts it into that is permanently bound to GTP. What does this do to rap activity, how does this impact signaling path ways that control cell division, and what type of gene is the mutated ras?
when was mutates in the way described, becoming permeantly bound to GTP, this means its perm. switched on, activating cell division. Ras mutated in this way is an oncogene, since the non-muted version (proto-oncogene) normally promotes cell division only under the correct circumstances, unlike a tumor suppressor which normally suppresses cell division.
The most significant and general defect of cancer cells is:

a. Over-expression of many genes
b. Tendency to undergo programmed cell death (apoptosis).
c. Inability to initiate cell division
d. Chromosomal deletions
e. Inability to repair DNA damage
e
Retinoblastoma protein (RB) binds to transcription factor E2F, this interaction a. Deactivates E2F preventing transition to S-phase b. Activates E2F stimulating transition to S-phaseaProto-oncogenes usually produce factors which: a. stimulate cell division b. inhibit cell divisionaThe SCA (1), is caused by a (2) in the B-hemoglobin (Hb) (3) that changes a T to and A nucleotide, converting glutamine to a valine. In individuals that are (4) for the HbS (SC) (5), hemoglobin molecules stick together, forming polymers that distort the shape of red blood cells into a "sickle" shape. Abnormal shaped cells can accumulate in blood vessels leading to blockages and severe pain. Anemia results as the abnormal red blood cells are rapidly broken down by the body. Word Choices: Homozygous, trait, SNP, allele, gene(1) trait (2) SNP (3)gene (4) homozygous (5)alleleGenes are: a. deterministic b. probabilisticbWhat causes identical genetic twins to be different? a. SNPs b. They have diff. alleles c. Gene expressioncWhat is the correct order for DNA packaging inside a eukaryotic cell: Words: chromatosome, DNA, 300 nm fiber, Nucleosome, Chromatin fiber, chromatid, 30 nm fiberDNA> nucleosome> chromatin fiber> chromatosome> 30 nm fiber> 300 nm fiber> chromatidWhat physical property of histone proteins allow DNA to tightly bind? a. negative charge b. supercoiling c. positive chargecEukaryotic DNA is packaged into chromatin fibers. What is the basic repeating structural, and functional, unit of chromatin? a. Histone b. Chromatid c. NucleosomecWhich type of DNA is highly condensed and has gene that are silenced or suppressed? a. Heterochromatin b. EuchromatinaDNA looping and supercoiling of bacterial chromosomes is necessary to: a. Compact the DNA so it can fit inside the cell. b. increase the size of DNA so that it can be accessed by transcription factors. c. Localize the DNA to the end of a cell in order to allow bacteria to divideaWhich of the following is NOT an advantage of DNA storage? a. It allows for preservation of data for hundreds of thousands of years b. it allows for storage of. vast amount of information in a small space c. It allows for fast repeated access to stored informationcHow was DNA re-purposed for storage of digital information? a. individual nucleotides were converted to analog signals b. individual codons were converted into binary numbers. c. individual codons were converted into analog signals d. individual nucleotides were converted into binary numbersbA nucleotide consists of: a. A sugar, a nitrogenous base and one or more phosphate groups b. A sugar and nitrogenous base c. A nitrogenous baseaDNA secondary structure is formed from two antiparallel strands joined by hydrogen bonds b/t bases. Which base pairing is correct? a. A with G b. A with C c. A with TcNucleotides in a DNA strand are arranged in what orientation? a. 5' to 3' b. 5' to 5' c. 3' to 3' d. 3' to 5'aWhich is the most common form of DNA helix? a. B b. A c. ZaCore histones make up the histone octamer around which DNA wraps to from a nucleosome. Which protein families are core histones? a. H1 and H5 b. H1, H2A, H2B, H3 c. H1, H2A, H2B, H3, H4, H5 d. H2A, H2B, H3, H4dCentromeres are made up on short repetitive sequences of DNA, what type of chromatin fiber is formed? a. constitutive heterochromatin b. euchromatin c. facultative heterochromatinaHistone acetylation results in chromatin that is: a. supercoiled b. tightly packed c. loosely packedcMitochondrial proteins are encoded: a. only in the nuclear genome b. only in the mitochondrial genome c. in both mitochondrial and nuclear genomescMitochondrial DNA is inherited from a. mothers b. fathers c. bothaMitochondrial Eve lived ~200,000 years ago, she was: a. the partner of Y-chromosome Adam b. the first woman c. the mother of all humans alivecThe impact of mitochondrial mutations can vary between cells in a body, this is because: a. mitochondrial mutations impact the function of specific tissues b. mitochondrial mutations are only detrimental at certain stages of development c. different cells can have different numbers of defective mitochondriacWhich of the following statements is correct? Membrane bound organelles: a. separate cellular machinery to provide conditions for specific activities b. promote mixing of the cellular machinery to speed up reactionsaDo mitochondrial (mtDNA) and chloroplast (cpDNA) DNA interact with histones? a.yes b. no c. what are histones? d. IDKbDuring replication, the DNA double helix is unwound by the action of: a. helicase b. primase c. topoisomeraseaDuring replication, supercoiling can cause over-winding of the DNA, this is prevented by the action of: a. primase b. helicase c. topoisomerasecDNA synthesis proceeds from a. 3' to 5' b. 3' to 3' c. 5' to 3' d. 5' to 5'cThe end replication problem refers to difficulties in copying linear chromosomes, this is overcome by the activity of telomerase, which: a. elongates the parental strand at the 3' end using an RNA template b. completes synthesis of the lagging strand using a primase c. synthesizes an RNA primer at the 3' end to start DNA replicationaDNA replication is described as "semi-conservative" this means that, after every round of replication a. half of the new DNA double helices are composed of entirely of old DNA, and the other are completely new b. Double helices consist of one strand of old DNA bound to one strand of newly synthesized DNA c. double helices are hybrids of old and new DNA, with greater amounts of new DNA following each roundbHow would DNA replication be affected in a cell lacking DNA gyros (topoisomerase)? a. DNA replication would occur, but at a slower rate b. Supercoiling would be reached c. DNA replication would halt d. the leading and lagging strands would switchcWhat would be the result of a mutation that increase MCM expression? a. enhanced DNA replication b. stalled DNA replication c. cell proliferation d. disproportionate replication of the leading and lagging strands e. A and CeA point mutation causes the following change to DNA: a. change in a single nucleotide b. change in the number of tandem copies of a specific locus c. change in the orientation of a chromosomal fragmentaOne type of beta-thalassemia is caused by a. an insertion b. a deletion c. a substitutionaDe-amination can circumvent DNA repair mechanisms and lead to base pair substitutions because a. deamination converts cytosine to uracil causing a base-pair mismatch b. deamination results in base pair excursion leading to a deletion c. deamination converts methylated cytosine to thyminecDamage to DNA by UV light can cause adjacent nucleotides to stick together, this is repaired by a. nucleotide repair b. homologous recombination c. base excision repairadsDNA breaks are the most damaging type of mutation. Which type of repair mechanism can introduce mutations, deletions and fusions in an effort to fix dsDNA breaks? a. direct reversal b. homologous recombinations c. non-homologous end-joiningcWhat is the genetic cause of thalassemia? a. mutation on the HBA and HBA2 genes b. Mutation in the HBB gene on chromosome 11bA codon that specifies the amino acid glutamine in the beta hemoglobin gene undergoes a single base sub. to become mis-sense mutation GAG->GTA. This mutation is a : a. transition: (A<->G or T<->C) b. transversion (A/G<->T/C)bWhich general transcription factor recognizes and binds to the TATA box? a. TBP b. TFIID c. TFIIAamRNA stands from messenger RNA which is produced during transcription, is this made up of the bases: a.A,T,C,G and U b. A,C,G, and U c. A,T,C, and GbSex-determination in turtles involves alternate splicing of a transcription factor. Why would intron inclusion result in a truncated protein? a. intron inclusion results in a shorter transcript b. intron inclusion results in a premature stop codon c. intron inclusion results in 5' de-capping of the transcript d. intron inclusion results in a longer transcriptbWhich site is the growing amino acid chain bound to within the ribosome, before transfer of an amino-acid a. A b. E c. PcIn bacteria the ribosome is positioned to allow binding of the initiator tRNA by a. The Shine-Dalgarno sequence b. the AUG start codon C. the 5' mRNA capaIn eukaryotes the initiator tRNA a. starts the process of translation b. catalyzes translocation along the mRNA chain c. identifies the start codon during scanning of mRNAcGTPase activity of initiation eEF2 catalyzes a. proofreading of the aminoacyl-tRNA to ensure high fidelity of translation b. selection and release of an aminoacyl-tRNA into the A site of the ribosome c. Translocation of the ribosome along the mRNAcIn eukaryotes translation termination occurs when a. The ribosome reaches the end of an mRNA and falls off b. the ribosome subunits dissociate from the mRNA and the remaining tRNA molecules are released c. eRF1 binds in the A site and catalyzes hydrolysis the peptidyl-tRNAcTetracycline antibiotics target both gram positive and gram negative bacteria by inhibiting initiation of translation. Using your knowledge of the process, infer which of the following mechanisms they use: a. attaching to the m7G cap preventing binding of the pre-initiation complex b. attaching to the 30S subunit and preventing aa-tRNA binding at the A site c. attaching to the P site, preventing peptide bond informationbWhich one of the following statements is not correct? Genes in an operon: a. share the same translational regulation, but are transcribed individually b. tend to be involved in related functions within a cell c. form a single polygenic transcript under the control of one promoter d. share the same transcriptional regulation, but are translated individuallyaGenes are found arranged in operons in: a. both prokaryotic DNA and nuclear eukaryotic DNA b. Prokaryotic DNA c. Nuclear eukaryotic DNAbAllosteric regulation is the process by which a. genes on a polygenic mRNA are activated b. transcription is inhibited by preventing binding of an RNA-polymerase to the promoter c. the shape and functional properties of a protein are changed by binding of a substrateccAMP is formed and activates Lac operon via the protein CAP when: a. lactose is absent and glucose is present b. lactose and glucose are absent c. lactose is present and glucose is absent d. lactose and glucose are presentcThe top operon encodes for genes that are involved in the synthesis of the amino acid tryptophan, it is an example of a repressible operon. This means: a. when tryptophan levels are high, binding to RNA-polymerase changes its shape preventing transcription b. when tryptophan levels are high, binding to the top repressor changes its shape preventing binding to the operator c. when tryptophan levels are high, binding to the top repressor changes its shape facilitating binding to the operatorcProkaryotic genes belonging to an operon are transcribed as a single transcript. Multiple proteins are produced by a. binding of ribosomes to internal Shine-Dalgarno sequences in the mRNA b. Peptidase activity that cuts the protein product into individual sequences c. splicing of the transcript to produce distinct coding sequencesaThe regulator protein that acts on a negative inducible operon is synthesized as: a. an inactive activator b. an active activator c. an active repressor d. an inactive repressorcThe regulator protein that acts on a negative repressible operon is synthesized as a. an active repressor b. an inactive repressor c. an inactive activator d. an active activatorbA hypermethylated CpG island is the promoter region is indicative of a gene which is a. undergoing replication b. highly expressed c. transcriptionally inactivecFollowing a period of strarvation, several genes in a lab mouse acquired DNA methylation. As an epigenetic modification, this means the change could a. permanently alter the genetic code b. persist until chromatin has been condensed then be erased c. persist through several rounds of replicationcEnhancer elements are short sequences of DNA, recognized and bound by transcriptional activators. They can be located a. upstream of the transcriptional start site b. in introns c. within the coding region of a gene d. >100kb from the transcriptional start site e. All of aboveeRNA interference was first identified by observing the twitching behavior of forms. It was found gene activity. was silenced by a. single stranded RNA that binds to target proteins b. DOuble stranded RNA matching the sequence of target genes c. Single stranded RNA complementary to target genesbdsRNA is processed by which enzyme to form siRNAs a. dicer b. argonaute c. RISCa