When early systematists distinguished chondrichthyes (cartilaginous fish) from osteichthyes (bony fish), it was not clear exactly when bony skeletons first appeared in the vertebrates. which of these suggests that a reduction of bone in chondrichthyes is a derived condition that emerged after the origin of bony skeletons? a) all fish except agnatha have jaws.
b) chondrichthyes and osteichthyes have paired fins and lateral lines. c) traces of bone tissue are found in living and fossil chondrichthyes. d) the cartilage skeleton of chondrichthyes is impregnated with calcium.

Which of the following best describes homeostasis? a. keeping the internal environment in a stable state b. keeping the external environment in a stable state c. beneficial characteristics resulting from mutation d. reproduction that results in offspring identical to the parent.

Dominance the dominant allele doesn’t fully mask or hide the recessive. for example, a red carnation with a white carnation will produce a carnation. one gene one trait. well most of the time than one gene controls a trait. we are all different but genetically speaking we are % similar with regards to genetic makeup.

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? question 8 options: the cold balloon expands and rises. the warm balloon shrinks and sinks. the balloons rise at the same rate. both balloons are the same size. the ballons both rise. the cold ballon is larger than the warm balloon. the warm balloon expands and rises. the cold balloon shrinks and sinks.