Historically, Betelgeuse, a red supergiant in the constellation of Orion, has been one of the brightest stars in the night sky. However, between September 2019 and February 2020, the star apparent magnitude changed dramatically. (A) Use the graph of the magnitude of Betelgeuse provided below (Nature 2020) and calculate the change in brightness of the star.   

The lac operon in E. coli codes for genes that are involved in breaking lactose into glucose and galactose when the cell needs to use those for energy. Expression of the lac operon is lowest when glucose levels are [a] and lactose levels are [b]. Hint: think this through logically if you don’t remember how the lac operon works.

A mammal has the genotype EeFf (the two genes are unlinked). Gene E determines eye color and gene F determines fur color. When the mammal produces gametes, those gametes could have different combinations of alleles that are given to the offspring. If gamete production occurs normally, which of the following allele combinations would NOT be found in one of its gametes?

Which of the following statements about codons is accurate?

Which of the following is needed to initiate RNA synthesis in a eukaryotic cell? Choose both correct answers.

In eukaryotes (such as humans), two individuals can be born that are genetically identical, but they can end up with slightly different phenotypes from each other. How does epigenetics explain this?

Proteins carry out a wide variety of cellular functions, including serving as enzymes, forming structural components of cells, transporting things within a cell, facilitating cell-cell recognition, receiving signals, and transporting things across membranes. Because of this, protein synthesis is very important in cells. In a cell, [a] are responsible for synthesizing the primary structure of a protein; this process is called [b].

What is true of transcription in both prokaryotes and eukaryotes?

Which of the following statements accurately characterize(s) epigenetic regulation?

Prokaryotic and eukaryotic cells can regulate gene expression. Which of the following mechanisms is seen both prokaryotes and eukaryotes? Choose all that are correct.