Topic 6 - Kingdom Animalia Flashcards
What is the structure of Cnidarians
Radially symmetrical, restricted to an aqueous medium for support. They have a hydrostatic skeleton formed by the fluid- filled entreon
What are Cnidarians restricted to aqueous medium
They have no means of restricting water loss across their body surface
What is the structure of Platyhelminthes
Bilaterally symmetrical and flattened dorso-ventrally
What is an advantage of the Platyhelminthes structure
The bilateral symmetry is that the animals have a ‘front’ where sensory receptors can be positioned to test the environment
It makes movement much easier
What is an advantage of the Dorso-ventral flattening in Platyhelminthes
It increases the surface area to volume ratio
It increases oxygen uptake
It decrease diffusion distance
What is the structure of Annelids
Rounded in the cross-section and are bilaterally symmetrical. They have spaces within the tissue that lies between body surface and gut, a coelom
What are advantages of Annelids possessing a Coelom
The ratio of surface area to metabolically active tissues is increased
It can function as an effective hydrostatic skeleton
The muscles involved in locomotion are separated from the gut muscles
It provides room for the development of organs
What is the term metamerically segmented is Annelids
The body is divided into a large number of structurally similar segments, each with its own body cavity
What is an advantage of Annelids have a one-way gut system
It allows regional specialisation and prevents food waster following digestion being mixed up with incoming food
What is the structure of Arthropods
Bilaterally symmetrical, with a fixed number of metameric segments in each region of the body. They have jointed limbs, one pair on each segment of the thorax and an exoskeleton
What is the most common animal group, and why
Arthropods, their body plan can be easily adapted to fill a wide range of niches
What are the 5 main groups within the Chordata
Fish, amphibians, mammals, birds, reptiles
What is the structure or Chordates
Bilaterally symmetrical and segmented, with the most continuous and proportional body cavity
What is the structure of vertebrates
A vertebral column with segmented muscle blocks, with the skeleton consisting of an internal jointed system of calcified bones
What are some evolutionary trends in the Kingdom Animalia
The gradation from radial symmetry to bilateral symmetry
The graduation from solid tissue between the body surface to the presence of cavities
The development of metameric segmentation
The development of a one-way gut
