Question

1. the genes that seem to be the most necessary to maintain, since they are present in the smallest cellular organisms are

a. cytoskeletal protein genes

b, translation protein genes

c. replication protein genes

d. transcription protein genes

e. DNA repair protein genes

2. Why do cellular organisms generally look very similar when early embryos but different from each other when mature?

a. their DNAs have different chemistry

b. their RNAs are different lengths

c. what genes get turned on and off when

d. the size of their genomes

e. the molecular biology if different organisms is different

3. which known molecular biological process is not part of the standard central dogma?

a. reverse transcription

b. reverse translation

4. the substrate binding site of a typical protein enzyme is usually

a. about 75% of the amino acids of the protein

b. about 25% of the amino acids of the protein

c. about 50% of the amino acids of the protein

d. only a few amino acids of the protein, usually consecutive in the primary structure

e. only a few amino acids of the protein, usually distant in the primary structure

5. the critical difference between Chargaff's experiment and those of Levene that allowed for development of Watson and Crick's model for the structure of DNA was that Chargaff

a. used DNA and levene RNA

b. used bacteria and Levene did not

c. determined that DNA was the genetic material

d. showed that the amounts of C, A, T, and G was constant for all organisms

e. showed that thymidine could be present in 2 tautomeric forms

6. The crucial characteristic of DNA that allows chromosome painting, which gives colored karyotypes is that

a. dna is double stranded

b. dna can be made into single strands and double strands reversibly

c. dna absorbs 260 nm light

d. dna is fluorescent

7. ATP dependent chromatin remodeling complexes

a. covalently modify dna

b. covalently modify histones

c. covalently modify themselves

d. undergo conformational changes when ATP is hydrolyzed

e. always remove histone H4 from the core nucleosomes

8. epigenetic inheritance of the state of chromatin (euchromatin or heterochromatin) is due to

a. the activity of barrier proteins

b. the activity of histone reader.writer complexes

c. the activity of chromatin remodeling complexes

d. the sequence of the DNA

e. transcription of the DNA

9. what technology is currently being used to generate the $1000 genome

a.didioxy sequencing

b.capillary sequencing

c.sequencing by synthesis (Illumina) sequencing

d. nanopore (Oxford nanopore) sequencing

e.single molecule (PacBio) sequencing

10.if you start a PCR rxn with one genomic copy of the region of DNA that you want to amplify, how many cycles of amplification do you need to perform before you have a double stranded DNA of the correct size

a.1

b.2

c.3

d.4

e.5

11.the energy required for nucleotide polymerization starting from a nucleotide triphosphate is derived from hydrolysis of which of the following

a. 1 carbon-carbon bond

b.2 carbon-carbon bonds

c. 1 phoaspate-phosphate bond

d. 2 phoaspate-phosphate bonds

e. 3 phoaspate-phosphate bonds

Answer 1

Ans 1) genes that seem to be the most necessary to maintain, since they are present in the smallest cellular organisms are cytoskeletal protein genes. A complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including bacteria and archaea, is known as cytoskeleton. It extends from the cell nucleus to the cell membrane and is composed of similar proteins in all organisms. it is composed of three main components in eukaryotes, microfilaments, intermediate filaments and microtubules, these are all capable of rapid growth or disassembly dependent on the cell's requirements. A number of functions are performed by the cytoskeleton. Its primary function is giving the cell its shape and mechanical resistance to deformation, and it also stabilizes entire tissue by association with extracellular connective tissue and other cells. The cytoskeleton can also contract, thereby deforming the cell and the cell's environment and allowing cells to migrate. Moreover, it is involved in many cell signalling pathways and in the uptake of extracellular material (endocytosis), the segregation of chromosomes during cellular division, the cytokinesis stage of cell division, as scaffolding to organize the contents of the cell in space and in intracellular transport (for example, the movement of vesicles and organelles within the cell) and can be a template for the construction of a cell wall. Furthermore, it can form specialized structures, such as flagella, cilia, lamellipodia and podosomes. The structure, function and dynamic behaviour of the cytoskeleton can be very different, depending on organism and cell type. Even within one cell, the cytoskeleton can change through association with other proteins and the previous history of the network.

Ans3) Reverse translation is not part of the standard central dogma.Translation is the biosynthesis of a protein from a messenger RNA template on ribosomes. Reverse translation is not a biological process. Instead, it is inferring DNA sequence from the amino acid sequence of a protein. Reverse translation is often employed to make a hybridization probe or a PCR primer used to clone the gene encoding the protein of interest. In most cases, the amino acid sequence of a protein is directly inferred from the DNA or mRNA sequence coding for the protein because each nucleic acid triplet (codon) specifies either single amino acid or a termination signal. The converse, determining the DNA or mRNA sequence coding for a specific amino acid, is more complex because the genetic code is "degenerate". In the nuclear DNA of eukaryotes, 61 codons specify 20 amino acids, so many amino acids are coded by more than one codon. This means that reverse translation of a protein does not produce a single nucleotide sequence. Instead, it results in a population of different sequences that, if translated, would all code for the same amino acid sequence. To identify the actual genomic sequence that codes for the protein in vivo, it is necessary to clone and sequence the gene for the protein. The first step in cloning is to synthesize a mixture of oligonucleotides (oligos) that corresponds to all of the potential coding sequences determined by reverse translation. This pool of oligos is used as a "degenerate" (mixed) hybridization probe to isolate the corresponding DNA or cDNA clone from a library. Alternatively, reverse translation is used to design two sets of "degenerate" PCR primers to amplify the gene from genomic DNA.