Blog

In 1928 Fredrick Griffith experimented with two strains of Streptococcus pneumoniae bacteria, smooth type (virulent) and rough type (non-virulent).  If heat-killed S type was mixed with R type, the mixture was virulent.  What was learned from this experiment?

Why are parasites so difficult to classify based on morphology only?

All animals must get oxygen to tissues for cellular respiration.  Which of the following is NOT involved in this critical function?

An organism has the following features: diplontic life cycle, protostome development, segmentation, a septate coelom, closed circulatory system, and setae. To which phylum does this organism belong?

A geneticist is studying sexual reproduction of a species of butterfly that lives in a very cold climate.  He hypothesizes that there should be low genetic diversity because it is well adapted to the cold climate but does not seem to be able to colonize surrounding areas with warmer climates.  What important principle is he using to formulate his hypothesis?

*Adult echinoderms display radial symmetry. What evidence suggests that echinoderm ancestors evolved from bilaterally symmetrical ancestors?

A primary tissue types that consists of scattered cells in a noncellular matrix is _____ tissue.

The tissue whose function is to move oxygen, carbon dioxide, nutrients, wastes, hormones, and heat around the body is _____.

On this temperature versus precipitation graph, the four areas plotted represent the ranges of temperatures and precipitations typical of four major types of biomes. Which choice correctly identifies the temperature and precipitation profiles for each type of biome?

Which of the organ systems listed below plays the most important role in protection of the human body from invasion by pathogens?