The name for the monophyletic group of animals that includes all reptiles, mammals, birds, and amphibians is the ----- . This group is characterised by the evolution and shared presence of  ----- . However, some members of this group do not possess this feature because of a process called  -----  loss. Snakes are famously legless reptiles, but other reptiles have also lost their limbs to varying degrees. Within the family ---- , we see species that have no limbs and some that have only hind limbs. In the genus ---- we can find species that have fully pentadactyl limbs, as well as those with only 3, 2, or 1 --- per foot.

The ancestors of extant tetrapods first evolved the ability to live out of water over 350 million years ago. Which of the following had to have been true for natural selection to have favored the original evolution of limbs? A) Closely related lineages that remained in the ocean must have gone extinct. There must have been differences in survival and or/reproduction based on size, musculature, bones or other (B functional aspects of early limbs. Large predators must have been a major source of mortality for populations that spent more time in the water and less on land. The ability of some ancestral fish-tetrapod transitional forms to move from one body of water to another during D droughts must have led to decreased mortality. E There must have been less competition for food on land.

What are HOX genes' role in lobe-finned fish to limbed tetrapod evolutionary transition?  -Please explain "how" HOX genes have influenced these limbs/appendages from an evolutionary standpoint. Thank you.

According to Richard Owen, the forelimbs of an adult human (with hands, adapted for grasping fruit from a tree), and the forelimbs of an adult bat (with wings, adapted for flight), are both derived from the same mammalian embryological structures, so they must represent: homologous structures, with similar embryonic anatomy, but different functions analogous structures, with different functions, and different embryonic anatomy analogous structures, with similar functions, but different embryonic anatomy analogous structures, with different embryonic anatomy, and different functions homologous structures, with different embryonic anatomy, but similar functions

Fill in the blanks: Specially evolved sound-producing structures in insects include the ____, which is found in Order Orthoptera and some ants and consists of sclerotized ridges on two parts of the body that are rubbed together to produce a chirping sound, and the ____, which is found in the cicadas and consists of a disk of exoskeleton that is rapidly oscillated, producing a loud buzz-like sound. Insects have a chordonotal organ in the pedicel of the antennae called the ____, which consists of cells called ____  that pull on sensory neurons. Give the name of one insect Order in which this structure is used in phonoreception: ____. Bioluminescence in insects involves specialized cells called ____, which contain the compound ____ that reacts with the enzyme ____ to produce heatless light.

Which of the following best describes the evolution of smell in chordates?     A) Ancestrally, jawless fish had few ancestral scent genes that coded for receptors resembling a combination of water and air receptors. Subsequently these genes were duplicated and specialized through natural selection either for use in water or air.     B) Ancestrally, all olfactory receptors where specialized for water as the ancestor of all vertebrates was aquatic. Only once did olfactory genes become duplicated and specialized and this was in the transition to land for receptors that work in air.     C) All chordates share the same number of scent receptor genes. However, they have become variously deactivated through natural selection due to either unuse or a tradeoff for sight genes.     D) None of the above.

The fossil record shows that the first mammals evolved 220 million years ago. The supercontinent Pangaea began to break apart 200 million years ago. On which continents would you predict that fossils of the first mammals will be found?