A researcher is interested in studying if drinking coffee makes people more or less impulsive (he doesn’t know which).  He collects two samples of subjects (100 subjects each) from the same population, one that drinks coffee (group 1) and one that does not (group 2).  He measures each on an impulsivity questionnaire, that ranges from 0 (not impulsive) to 100 (very impulsive).  He finds that coffee drinkers have an impulsivity of 75, whereas non-coffee drinkers have an impulsivity of 67.  He also calculates a standard error of the differences between groups (SEM1-M2) of 4.08. Calculate the test statistic (t-score) for this test (Two Independent Samples t-Test).

How does a bacteria protect itself from viral infections? Multiple answers are possible.

Mutation breeding was a common tool used by plant breeders to develop new varieties of crops. The use of mutation breeding has since been replaced by new genetic engineering tools like transformation and CRISPR. Which of the following is NOT an advantage these new tools have over mutation breeding?

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

The “endosymbiosis hypothesis” explains the in Eukaryotic evolution.  

Bilateral symmetry was a major evolutionary transition in the animal body plan that contributed to the Cambrian Explosion. What adaptive benefit did animals derive from evolving bilateral symmetry?

As humans spread around the world, they often adapted to local conditions, especially local diseases. One example is the evolution of greater resistance to the pathogen that causes malaria. The evolution of greater resistance to malaria has been observed in human populations from three regions (South America, Western Africa, and Southeast Asia). Recent genomic studies of these populations have identified several alleles related to malaria resistance that show evidence of selection based on SNP analysis. SNP is short for . What does it mean that these alleles show “evidence of selection”, from a genomic perspective?

One of the first commercially available genetically engineered drugs was Human Growth Hormone (HGH), which was used to treat human growth hormone deficiency. To produce HGH, genetic engineers modified the genome of the bacteria E. coli to express the HGH gene. To do this, scientists first had to create a DNA vector with a bacterial regulatory sequence and human coding sequence (insulin gene). This DNA vector, containing two genes from different organisms, is known as…

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

Processes in the thalamus are involved in cognitive judgments about pain, which contributes to the strong emotions often experienced during pain.