From Genes to Traits
These specific stretches of nucleotides within a DNA molecule are passed from parents to offspring and contain instructions for building molecules.
What are genes?
These are the smaller chemical subunits, or monomers, that connect in a specific order to make up a giant DNA molecule.
What are nucleotides?
This strict biological rule ensures the shape of nitrogenous bases fit together perfectly, meaning Adenine only pairs with Thymine, and Cytosine only pairs with Guanine.
What is complementary base pairing?
This is the specific phase of the cell cycle when a eukaryotic cell duplicates all of its chromosomes right before cell division.
What is the S phase?
This core enzyme builds new DNA strands by moving along a template strand and matching incoming nucleotides one by one in a 5' to 3' direction.
What is DNA polymerase?
These specialized organizing proteins act like spools to package and manage the single, long DNA molecule inside a chromosome.
What are histones?
Name the three distinct chemical components that make up a single DNA nucleotide monomer.
What are a 5-carbon sugar (deoxyribose), a phosphate group, and a nitrogenous base?
This term describes the opposite directionality of the two DNA strands, where the 5' end of one strand aligns perfectly with the 3' end of its partner.
What is antiparallel?
This term describes the pattern of replication where each newly made double helix preserves one original parent strand and contains one brand-new daughter strand.
What is semi-conservative?
This vital enzyme acts as a "molecular glue" that structurally joins disconnected fragments into a single, continuous strand of DNA.
What is ligase?
This specific property of a protein is determined by its sequence of amino acids and directly determines what job or function it performs in the cell.
What is its three-dimensional (3D) structure or shape?
This strong, alternating structure forms the rigid outer sides of the DNA ladder to hold the bases securely in place.
What is the sugar-phosphate backbone?
These intentionally weak chemical bonds hold the nitrogenous bases together in the center of the helix, acting like a "molecular zipper" that can easily open.
What are hydrogen bonds?
These are the hundreds or thousands of short nucleotide sequences along a chromosome where replication proteins bind to begin separating the DNA strands.
What are origins of replication?
This enzyme drives the initial step of replication by breaking the hydrogen bonds holding the two original strands together.
What is helicase?
Besides physical traits like hair color, name two other types of observable characteristics classified as inherited traits.
What are behaviors (e.g., mating/feeding patterns) and the risk of getting certain diseases?
State the full, formal biological names of the four different nitrogenous bases found in DNA.
What are adenine, thymine, guanine, and cytosine?
This specific chemical group marks the exact 5’ (five-prime) end of a single DNA strand.
What is a phosphate group?
State the primary evolutionary advantage of having thousands of starting points along a single eukaryotic chromosome instead of just one.
What is to speed up the process of copying an entire long chromosome?
Because DNA polymerase cannot start building from scratch, this enzyme must synthesize a short RNA starter molecule called a primer.
What is primase?
In black panthers, a genetic variation causes this cell-surface receptor protein to be highly active, resulting in an overproduction of dark eumelanin pigment.
What is the MC1R protein?
While the outer backbone provides structure, this specific property of the nitrogenous bases provides the actual "code" for an organism's unique traits.
What is the sequence (or order) of the bases?
This specific 5-carbon sugar molecule marks the exact 3’ (three-prime) end of a single DNA strand.
What is deoxyribose?
This is the name given to the opened, unwound region of DNA where copying takes place, and these are the two Y-shaped ends where the strands separate.
What is a replication bubble and replication forks?
This enzyme binds ahead of the advancing replication fork to relieve the severe overwinding strain and physical tension caused by unzipping the helix.
What is topoisomerase?