About 3 million years ago, the Isthmus of Panama (a narrow strip of land connecting North and South America) formed, dividing marine organisms into Pacific and Caribbean populations. Researchers have examined species of snapping shrimp on both sides of the isthmus. Based on morphology, there appear to be seven pairs of species, with one species of each pair in the Pacific and the other in the Caribbean. Researchers reconstructed a phylogeny using mitochondrial DNA sequences and found that each of the species-pairs, separated by the isthmus, were indeed each other's closest relatives. The researchers also found that species from many pairs were not very interested in courting with each other under lab conditions, and any that did mate almost never produced fertile offspring. The species pairs on opposite sides of the isthmus are true species under which species concept(s)?

2. in dragons, a gene on chromosome 1 codes for wing color and a gene on chromosome 2 codes for body color. draw out the stages of meiosis for these two chromosomes from a dragon that is heterozygous for both traits. define your alleles. what are all the possible allele combinations of the gametes produced?

With the description of the different cell walls, membranes, and associated proteins set in the students' minds, you now need to introduce them to the idea that the cell wall can also act as a foundation to build things upon. bacterial appendages require a strong foundation that will offer the support needed to move and function in a dynamic world. for example, flagella are long, whiplike protein structures that are used by many gram-positive and gram-negative bacteria for locomotion. in order to function effectively, a flagellum must be firmly anchored to the cell wall. how will you be able to get across the idea that the peptidoglycan cell wall is strong enough to support such a mechanism? with a protein rod that passes through the cell wall and protein rings used to anchor it in the membranes, these basal bodies are the rudimentary biological motors that use atp power to spin the hook and the flagella attached to it. bacterial flagella have a biological motor that spins within the cell wall and is powered by atp. this allows the flagella to spin in a whiplike motion to propel the bacterium.

Mr. olajuwan was in a horrific snowmobile accident. afterwards he had trouble walking and he had a loss of balance. which of the 4 major brain region was probably demaged