The following figure is from a study (Million et al. 2018) that compared the gut microbiota of individuals who had severe acute malnutrition (SAM) to individuals who didn’t (CTL). What can we conclude from these results? [answer1] Our gut microbiome is an example of both a/an [answer2] and [answer3] relationship.

A scientist wishes to genetically modify a rat so that it grows green hair. Which of the following methods would likely be the most efficient (least time intensive and least expensive), given its precise ability to edit genetic information?  

A genetic engineer is exploring methods to develop a new kiwi variety resistant to purple melon disease. They are considering two techniques: CRISPR-Cas9 gene editing, which allows targeted modifications in a specific gene linked to disease resistance, and mutation breeding, which induces a wider range of genetic changes. Which of the following best highlights an advantage of CRISPR-Cas9 over mutation breeding?

Identical (monozygotic) twins were adopted by different families at birth and were raised in different parts of the country. However, both twins grow up to have perfect pitch. This observation would suggest what about the shared musical talent of these twins?

Bacteria use restriction enzymes and Cas9 enzymes that target specific sequences of DNA to defend themselves against which of the following selfish genetic elements?

The statement that racial categories are social constructs, and have no basis in biology is, in part, predicated on observations of human genetic diversity.  Which of the following statements best describes the distribution of genetic variation among racial groups? 

Below are estimates for the heritability of several complex human traits. Which of the following statements is most accurate, based on these data? Trait heritability (h2) Height 0.79 Weight 0.70 Alcoholism 0.52

This phylogenetic tree depicts the evolutionary relationships of eight major vertebrate classes.  Tiktaalik is an intermediate fossil that represents an early ancestor of tetrapods (four-limbed animals) and the transition from water to shoreline. If you were to add Tiktaalik to this phylogeny, where would the Tiktaalik branch extend from?

Brain size and higher orders of intelligence are thought to be distinguishing features of humans (Homo sapiens).  As we learned in class, larger, more intelligent brains can evolve in other organisms too, like guppies. Why then aren’t more organisms “intelligent”?

What evidence in living cells today suggests that RNA was the first self-replicating “information” molecule?