Title: Deuterostome Diversity Post by: tama401 on Apr 4, 2011 Which characteristic distinguishes echinoderms from the other two deuterostome lineages?
Their ability to move Their habitat Their body plan The presence of an endoskeleton Which of the following statements about vertebrates is true? The development of an amniotic egg and internal fertilization allowed vertebrates to reproduce away from water. All vertebrates have jaws with which to catch their prey. Birds are more related to mammals than to dinosaurs. The development of more efficient surfaces for gas exchange in reptiles stimulated expansion into terrestrial habitats. Which characteristics define a chordate? The presence of four specific morphological traits The development of an anus from the blastopore The ability to live on land The presence of a well-developed circulatory system Which structure can be used for feeding and gas exchange? Dorsal nerve cord Pharyngeal gill slit Endoskeleton Notochord Title: Re: Deuterostome Diversity Post by: duddy on Apr 4, 2011 Which characteristic distinguishes echinoderms from the other two deuterostome lineages?
Their ability to move Their habitat --> Their body plan The presence of an endoskeleton Which of the following statements about vertebrates is true? The development of an amniotic egg and internal fertilization allowed vertebrates to reproduce away from water. All vertebrates have jaws with which to catch their prey. Birds are more related to mammals than to dinosaurs. The development of more efficient surfaces for gas exchange in reptiles stimulated expansion into terrestrial habitats. Which characteristics define a chordate? The presence of four specific morphological traits The development of an anus from the blastopore The ability to live on land The presence of a well-developed circulatory system Chordates form a phylum of creatures that are based on a bilateral body plan, and is defined by having at some stage in their lives all of the following: --> A notochord, in other words a fairly stiff rod of cartilage that extends along the inside of the body. Among the vertebrate sub-group of chordates the notochord develops into the spine, and in wholly aquatic species this helps the animal to swim by flexing its tail. --> A dorsal neural tube. In fish and other vertebrates this develops into the spinal cord, the main communications trunk of the nervous system. --> Pharyngeal slits. The pharynx is the part of the throat immediately behind the mouth. In fish the slits are modified to form gills, but in some other chordates they are part of a filter-feeding system that extracts particles of food from the water in which the animals live. --> A muscular tail that extends backwards behind the anus. --> An endostyle. This is a groove in the ventral wall of the pharynx. In filter-feeding species it produces mucus to gather food particles, which helps in transporting food to the esophagus. It also stores iodine, and may be a precursor of the vertebrate thyroid gland. Which structure can be used for feeding and gas exchange? Dorsal nerve cord --> Pharyngeal gill slit Endoskeleton Notochord |