chapter 9 Flashcards
a body plan in which an organisms can be divided into two parts that are nearly mirror images of each other.
bilateral symmetry
a body plan in which an organisms can be divided into two parts that are nearly mirror images of each other anywhere through its central axis.
radial symmetry
a body plan in which an organism can not be divided into any two parts that are nearly mirror images.
asymmetry
an inherited trait that increases an organism’s chance of surviving and reproducing in a particular environment.
adaptation
a fluid filled internal cavity surrounded by muscle tissue.
hydrostatic skeleton
a thick, hard outer covering; protects and supports an animal’s body.
exoskeleton
the internal rigid framework that supports humans and other animals.
endoskeleton
an animal that survives by living inside or on another organism, gets food from the organism, gets food from the organism, and does not help in the organism survival.
parasite
a thin layer of tissue that covers a mollusk’s internal organs.
mantle
a process in which an outer covering, such as an exoskeleton, is shed and replaced.
molting
a developmental processs in which the body form of an animal changes as it grows from an egg to an adult.
metamorphosis
a flexible, rod shaped structure that supports the body of a developing chordate.
notochord
grooves along the side of a developing chordate.
pharyngeal pouch
an organ that exanges carbon dioxide for oxygen in the water.
gill
a protective membrane that surrounds an embryo.
amnion
