Question | Answer |
What is the body plan of a platyhelminthes? | bilateral, acoelomate - no body cavity, 3 cell laters: mesoderm, endoderm, ectoderm, no circulatory or respiratory system. |
What is the body plan of nematode? | bilateral, pseudocoelomate - body cavity, 3 cell layers, have complete digestive system with mouth and a anus, no circulatory or respiratory system. |
What is the body plan of an annelid? | bilateral, coelomate - true body cavity, 3 cell layers, segmented bodies, have all organ systems |
Define hermaphrodite: | an organism that has both male and female reproductive parts that are functional |
Give three general characteristics of flatworms: | cephalized head, no body cavity, one opening: mouth, pharynx, eyespots to detect light. |
Give three general characteristics of roundworms: | bodies shaped like pencils sharpened at both ends, complete digestive system, separate sexes, some are parasitic, two openings: mouth and an anus - complete digestive system |
Give three general characteristics of annelids: | segmented bodies, paired appendages, parapodia, setae (bristles) |
Define acoelomate: | an organism with no body cavity |
Define pseudocoelomate: | an organism with a body cavity whose organs are not supported by mesodermal tissue |
Define coelomate: | an organism with a true body cavity and organs and organ systems are supported by mesodermal tissue |
What are the three classes of flatworms and give an example of each? | Turbellaria - Planarians, Trematoda - Blood flukes, Cestoda - tapeworms |
How do flatworms reproduce? | Asexual by regeneration and sexual by exchange of sperm |
How do roundworms reproduce? | Sexes are separate. Fertilization occurs in the body of the female. |
How do segmented worms reproduce? | Most reproduce sexually, some have separate sexes, some are hermaphrodites (asexual) |
Draw a diagram of an Earthworm and label: aortic arches, brain, pharynx, esophagus, seminal receptables, crop, gizzard, setae, clitellum, seminal vesicles and intestine. | |
Define aortic arches: | large, muscular tubes that alternately contract and relax, keeping blood flowing |
Define seminal vesicles: | reproductive organs which store sperm |
Define Intestine: | a tube responsible for the passage of waste products and absorption of nutrients |
Define Clitellum: | a swelling that produces a protective slim ring that covers the fertilized eggs as they are laid |
Define setae: | bristles used for locomotion |
Define gizzard: | a muscular organ containing grans of sand used to grind up food |
Define crop: | a round organ used to temporarily store food |
Define pharynx: | tubelike structure through which soil and food particles pass |
Esophagus: | a tubelike structure which food passes through to the stomach |
Nepridium: | one of many openings through which wastes are passed to the outside of the body |
What are the three tissue layers and what tissues do they give rise to (or make)? | ectoderm gives rise to skin tissues and nervous system
mesoderm gives rise to skeletal, muscular, reproductive systems
Endoderm gives rise to digestive system |
What is cephalization? | sensory information is contained in the head region of the animal (i.e. eyes, mouth, ears) |
What is regeneration? | The ability of an organization to replicate itself (grow whole organism) which is a type of asexual reproduction. Growing back of body structures. |