Which of the following is NOT a post-translational modification that can occur in some proteins.

In a classic experiment from the 1970s investigating gene expression, a solution containing equal amounts of rabbit a-hemoglobin mRNA and b-hemoglobin mRNA, which encode subunits of a protein found in red blood cells, was injected into newly fertilized frog eggs. The injected mRNA was not degraded during the course of the experiment. Tadpoles that developed from the injected eggs were dissected into two fragments, one containing predominantly the notochord, muscle tissue, and nerve tissue and the other containing predominantly the other tissue types. Equal amounts of total protein were analyzed after separation by electrophoresis to identify the relative amounts of the different proteins present in each sample. The thickness of the bands indicates the relative amounts of rabbit a-hemoglobin, rabbit b-hemoglobin, and frog tubulin (a cytoskeletal protein that is expressed at relatively constant levels in all tissues) present in each tadpole sample. The experimental protocol and results are summarized in the figure below. ” At the top left, a test tube labeled Rabbit Hemoglobin mRNA is shown. An arrow points to a circular egg with dots inside, labeled Injected into Eggs, with a syringe injecting the mRNA into the egg. An arrow points to the right showing the egg develops and is labeled Reared to Tadpoles, with an illustration of a tadpole showing a black body upper half and grey tail. An arrow points downward from the tadpole to another tadpole illustration labeled Tadpoles Dissected. This tadpole has a white line bisecting the top of the body from the bottom. Two arrows branch downward from this tadpole. The left arrow points to a top tadpole section labeled Notochord, Muscle, and Nerve Tissues. The right arrow points to a bottom tadpole section labeled Other Tissues. From each section, an arrow points downward to a gel electrophoresis results box with the header Protein Isolation and Analysis. The results are shown in a table with three rows and two columns. The rows are labeled on the left with the proteins being tested: Frog Tubulin, Rabbit beta-hemoglobin, and Rabbit alpha-hemoglobin. The first column tests Notochord, Muscle, and Nerve Tissues, showing a thin band for Frog Tubulin, a thick dark band for Rabbit beta-hemoglobin, and a thin band for Rabbit alpha-hemoglobin. The second column tests Other Tissues, showing a thin band for Frog Tubulin, a thick dark band for Rabbit beta-hemoglobin, and a thin band for Rabbit alpha-hemoglobin.” Given that equal amounts of the different mRNA’s were injected into fertilized frog eggs, which of the following conclusions is most consistent with the electrophoresis results?

Frederic Griffiths experiments involved two different strains of a bacteria that causes pneumonia in mammals: a disease causing strain, called the smooth strain, and a harmless strain, called the rough strain. As expected, when healthy mice were injected with the smooth strain they died, and when there were injected with the rough strain they lived. When the smooth strain bacteria were killed with heat and injected into healthy mice, the mice were fine. However, when heat-killed smooth strain bacteria and rough strain bacteria were injected together into healthy mice, the mice died. The now pathogenic bacteria passed on that trait to their offspring. This indicates that

tRNA molecules pick up ______ in the cytoplasm and bring them to the ribosome.

Experiments have confirmed that mRNA is read by ribosomes in codons comprised of ___ base(s).

In most cases, regions of DNA with high levels of methylation are

The reaction between aqueous strontium chloride (SrCl2) and aqueous potassium sulfate (K2SO4) forms a precipitate of strontium sulfate (SrSO4). Which of the following represents the net ionic equation for the reaction?

The figure presents a particle diagram. There are four H 2 molecules and four O 2 molecules spread throughout the diagram.   A mixture of H2(g)and O2(g) is placed in a container as represented above. The H2(g) and O2(g) react to form H2O(g). Which of the following best represents the container after the reaction has gone to completion?

Which of the following pieces of laboratory glassware should be used to most accurately measure out a 25.00 mL sample of a solution?

A student obtains a liquid sample of green food coloring that is known to contain a mixture of two solid pigments, one blue and one yellow, dissolved in an aqueous solution of ethanol. Which of the following laboratory setups is most appropriate for the student to use in order to separate and collect a substantial sample of each of the two pigments?