DNA Structure: Key Concepts and Discoveries

<p>Histones (B)</p> Signup and view all the answers

<p>Metaphase (D)</p> Signup and view all the answers

<p>Inactive genes and heterochromatin (C)</p> Signup and view all the answers

<p>700 nm (C)</p> Signup and view all the answers

<p>Histones (B)</p> Signup and view all the answers

<p>To ensure each daughter cell receives an identical copy of DNA (B)</p> Signup and view all the answers

<p>S phase (D)</p> Signup and view all the answers

<p>Semiconservative model (A)</p> Signup and view all the answers

<p>Cytosine pairs with guanine (B)</p> Signup and view all the answers

<p>One strand can recreate a complementary strand (D)</p> Signup and view all the answers

<p>It allows for accurate copying of genetic information (C)</p> Signup and view all the answers

<p>They remain intact and serve as templates (B)</p> Signup and view all the answers

<p>It extends the telomeres during DNA replication (A)</p> Signup and view all the answers

<p>The small size of prokaryotic genomes and availability of variants (C)</p> Signup and view all the answers

<p>42 minutes (D)</p> Signup and view all the answers

<p>1000 nucleotides/s (D)</p> Signup and view all the answers

<p>Eukaryotes possess telomerase. (A)</p> Signup and view all the answers

<p>Mismatch repair (A)</p> Signup and view all the answers

<p>Nucleotide excision repair (C)</p> Signup and view all the answers

<p>They are edited through a proofreading mechanism (C)</p> Signup and view all the answers

<p>Prokaryotic chromosomes are circular (B)</p> Signup and view all the answers

<p>Three mRNA nucleotides (A)</p> Signup and view all the answers

<p>Nucleus (A)</p> Signup and view all the answers

<p>It determines the rate of gene transcription (D)</p> Signup and view all the answers

<p>To synthesize RNA from the DNA template (C)</p> Signup and view all the answers

<p>The template strand (B)</p> Signup and view all the answers

<p>Uracil (B)</p> Signup and view all the answers

<p>The RNA polymerase must bind to a promoter (A)</p> Signup and view all the answers

<p>In the cytoplasm (A)</p> Signup and view all the answers

<p>Genetic code (C)</p> Signup and view all the answers

<p>64 (B)</p> Signup and view all the answers

<p>Methionine (C)</p> Signup and view all the answers

<p>They signal the end of protein synthesis. (B)</p> Signup and view all the answers

<p>Enzymatic proteins (C)</p> Signup and view all the answers

<p>A site (A)</p> Signup and view all the answers

<p>The universal use of the genetic code (B)</p> Signup and view all the answers

<p>Replication (D)</p> Signup and view all the answers

<p>It prevents the binding of RNA polymerase to the promoter. (C)</p> Signup and view all the answers

<p>It undergoes a conformational change and can no longer bind to the operator. (B)</p> Signup and view all the answers

<p>At multiple stages including transcription and translation. (D)</p> Signup and view all the answers

<p>Within the nucleus. (C)</p> Signup and view all the answers

<p>To initiate transcription when RNA polymerase binds to it. (C)</p> Signup and view all the answers

<p>It separates transcription and translation processes. (B)</p> Signup and view all the answers

<p>The binding of lactose to the repressor protein. (B)</p> Signup and view all the answers

<p>Ribosomes in the cytoplasm. (B)</p> Signup and view all the answers

The process where a cell creates an identical copy of its DNA.

The phase of the cell cycle when DNA replication occurs.

Two DNA strands where one strand's sequence determines the other's.

Each new DNA molecule has one original and one new strand.

New cells produced as a result of cell division.

Original strand of DNA used to create a new strand during replication.

Process where a single cell divides to produce two or more identical cells.

Enzyme responsible for maintaining telomeres. Crucial to DNA replication at the end of chromosomes.

Prokaryotic DNA is supercoiled to fit within the cell, using proteins that twist and maintain this structure.

Eukaryotic DNA is organized by wrapping around histone proteins to form nucleosomes, making up a condensed structure, ultimately fitting inside the nucleus.

Basic structural units of eukaryotic chromosomes, where DNA coils around histone proteins.

The complex combination of DNA and proteins (like histones) that makes up chromosomes.

A twisting beyond the double helix structure to pack DNA tightly within prokaryotic cells and in certain viral DNA.

Proteins around which DNA is wrapped to form nucleosomes.

A highly condensed chromosome, ~700 nm wide, visible during the metaphase stage of cell division.

Chromosomes are less condensed, active during interphase in cell cycle.

Prokaryotes replicate DNA at a rate of approximately 1000 nucleotides per second.

Prokaryotic DNA replication starts from a single origin of replication.

Eukaryotic DNA replication is much slower, approximately 50 to 100 nucleotides per second.

A DNA repair process that corrects mistakes in base pairings not caught during replication.

A DNA repair process that removes damaged nucleotides.

Two adjacent thymine nucleotides bonded together instead of their complementary bases.

A process immediately after DNA synthesis where DNA polymerase checks for mistakes and makes necessary corrections.

The process where DNA is used as a template to create a messenger RNA (mRNA) molecule.

The region of DNA that is unwound during transcription, allowing access to the template strand.

A specific DNA sequence that signals the start of a gene, where transcription machinery binds.

The strand of DNA used as a template for mRNA synthesis during transcription.

The strand of DNA that is not used as a template during transcription, it's almost identical to the mRNA.

An enzyme that reads the template strand and synthesizes mRNA, adding RNA nucleotides.

The stage where RNA polymerase moves along the template strand, adding nucleotides to build the growing mRNA strand.

The stage where RNA polymerase encounters a stop signal in the DNA sequence, signaling the end of transcription.

The set of rules that translates nucleotide codons in mRNA into specific amino acids, forming proteins.

A sequence of three nucleotides in mRNA that specifies a particular amino acid or signals the end of translation.

The first codon in an mRNA sequence that initiates protein synthesis; usually AUG, encoding methionine.

One of three codons (UAA, UAG, UGA) that signals the termination of protein synthesis.

The assembly of components that starts protein synthesis, including the small ribosomal subunit, mRNA, initiation factors, and initiator tRNA.

The site on a ribosome where incoming charged tRNAs (tRNAs carrying amino acids) bind during protein synthesis.

The site on a ribosome where the tRNA carrying the growing polypeptide chain is bound.

The same genetic code is used by almost all living organisms on Earth, indicating a common ancestor.

A group of genes in bacteria responsible for lactose metabolism, controlled by a switch-like mechanism.

A protein that binds to the operator region of the lac operon, blocking transcription of the lactose-metabolizing genes when lactose is absent.

A molecule that binds to the repressor protein, changing its shape and preventing it from binding to the operator, allowing transcription.

The process of reading RNA to make proteins.

The control of gene expression in eukaryotes, which occurs at multiple stages from DNA to protein.

Gene regulation that affects DNA's structure, not its sequence, influencing how tightly it is packaged.

Gene regulation occurring after RNA is made, affecting its processing and transport.