T(th) cells recognize antigens when they are bound to a(n)
a. hapten.
b. immunoglobulin.
c. natural killer cell.
d. major histocompatibility complex (mhc) protein.

The collared lizard is a species found in the desert southwest. male collared lizards show considerable color variation, ranging from brightly colored to a very dull pattern. your goal is to determine the function, if any, of male color patterns in collared lizards, using the scientific method. your tentative explanation is that male color plays a role in attracting females for mating purposes. you predict that females will preferentially choose brightly colored males over dull-colored ones. to test this prediction, you observed the interactions of female collared lizards with their male counterparts. you selected males that were the same age and size, and that differed only in their coloration pattern. you placed equal numbers of the two types of male lizards, bright and dull, in aquariums, along with one female lizard per aquarium. out of 350 aquariums observed, the female chose to mate with the brightly colored male 277 times, and the dull-colored male 70 times. in 3 instances, the females did not mate with either type. create a bar graph of your data, plotting the type of male (dull or brightly colored) on the x-axis. on the y-axis, plot the frequency with which each type of male was chosen by females. using this graph, answer the following question(s). is it reasonable to conclude (i. e., is it supported by the data) that female collared lizards prefer more brightly colored male lizards over dull-colored males?

Despite the differences in mature plant cells, all of them are derived from meristem cells. the three major types of tissue systems develop from the meristem. meristems develop cells in all but which tissue?

In pea plants, the allele for inflated pod seed, i, is dominant over the allele for constricted pod seed, i. the punnett square shows a cross for this trait. which offspring will be homozygous dominant