Which of the following characteristics evolved independently in mammals and birds?
a) bilateral symmetry
b) amniotic eggs
c) jaws
d) bone
e) endotherm

Which statement best describes a keystone species? o a. it has littlelmenetic variation. it has an extremely high population. 0 b. 0 c. it remains unaffected by all environmental changes. od. it has a strong influence on the ecosystem. 0 e. it's the first species to populate a new ecosystem.

Match the following terms describing electrical events with the correct phases of the cardiac cycle. the ventricular muscle cells depolarize at the start of this phase. during this phase, na+ entry through the funny channels causes the pacemaker potential of sa nodal cells to gradually become less negative until it reaches threshold. the ventricular muscle cells repolarize right before this phase. the cytosolic concentration of calcium in the contractile cells of the ventricle is highest during this phase. a. isovolumetric relaxation b. ventricular ejection c. isovolumetric contraction d. ventricular filling

The equation shows cellular respiration. during cellular respiration, glucose combines with oxygen to form carbon dioxide, water, and atp. what happens to the energy in the bonds in glucose? the energy is transferred to oxygen. the energy is transferred to carbon dioxide. the energy is transferred to water. the energy is transferred to atp.