Chapter 30 Flashcards
What is Kingdom Animalia in the tree of life?
Eukaryotic, Monophyletic clade, common ancestor with Choanoflagellates, closely related to Fungi,
What are some characteristics of animals?
Multicellular, no cell walls (extracellular matrix), heterotrophic, get nutrition by ingestion, most animals (except sponges) have tissues
What does the life cycle of an animal look like?
Most reproduce sexually (some can reproduce asexually), diploid cells (2N) are dominant (Only gametes are haploid), early embryonic development (cleavage, blastula stage, gastrulation, gastrula stage)
What % of animals go through metamorphosis?
80%
What are some characteristics of choanoflagellates?
Protists, single-celled or colonial, live in fresh & salt water
What are some similarities and differences between Choanoflagellates and Phylum Porifera (sponges)?
Both feed the same way (filter-feeders), both are eukaryotes, and both are sessile (immobile). Choanoflagellates are single-celled or colonial protists, and sponges are multicellular animals.
What are tissues?
Group of specialized cells that are separated from other tissues by membranous layers. They come from embryonic germ layers and are formed after gastrulation
What are the classifications of animals based on tissues?
Metazoa - all animals, Parazoa - animals with no specialized tissues (sponges), Eumetazoa - have more than one type of tissue (all animals besides sponges)
What is cleavage?
Mitotic (Mitosis) cell division without growth of the cell ball.
What happens to the zygote during blastula development?
The zygote divides into smaller cells from one cell, to eight cells, to eventually the blastula.
How does the gastrula form?
The blastula folds into the blastocoel (inside) and forms germ layers.
What consists of the gastrula?
The blastopore (first opening in the gastrula), ectoderm (outside layer), endoderm (inside layer), and mesoderm.
What are germ layers and what do they do?
Embryonic layers that develop into various tissues in the body. Ectoderm is the outer covering and develops into nervous tissue. Endoderm is the lining and develops into organs of the digestive tract. The mesoderm develops into the circulatory system, muscles, and some organs.
What is diploblasty and what phylum is diploblastic?
Organisms that only have 2 germ layers (endoderm and ectoderm), are radially symmetrical, neural net, and have no coelom (acoelomate). Phylum Cnidaria are diploblastic.
What are some characteristics of Phylum Cnidaria?
Jellyfish, coral, sea anemone, hydra, diploblastic, radial symmetry, and neural net.
What are the types of body symmetry?
Radial symmetry - an organism that can be divided into two equal parts from multiple angles around the center point. Radially symmetric organisms are usually sessile or planktonic and experience the environment from all sides. Bilateral - an organism that can only be divided into two equal parts by only one line. Bilaterally symmetrical organisms have a central nervous system.
What is the difference between a neural net and a central nervous system?
The neurons in a neural net are grouped together while a central nervous system has them all spread apart.
What is triploblasty?
Has all 3 germ layers (ectoderm, endoderm, mesoderm) and a body cavity (coelomate)
What is a coelom?
A body cavity - fluid-filled space that separates the digestive tract from outer body wall by the mesoderm
What are the coelom types?
Coelomate (body cavity is completely lined with mesoderm), pseudocoelom (body cavity only has one layer of mesoderm; not fully covered), acoelomate (no body cavity; lost during evolution)
Why do animals have a coelom (body cavity)?
The fluid in the body cavity acts as a cushion for organs and a skeleton in soft-bodied animals. It also provides more space for organs to grow and move independently from the outside of the body.
What is the fate of the blastopore in protostomes and deuterostomes?
In protostomes, the blastopore (first hole in blastula) becomes the mouth, and the cleavage is spiral and determinate. In deuterostomes, the blastopore becomes the anus and the cleavage is radial and indeterminate.
What are the “superphyla” of protostomes?
Lophotrochozoa - lophos means ciliated structure, Some have trochophore larvae before metamorphosis or a lophophore stage as an adult. Ecdysozoan animals secrete and shed external skeletons (exoskeletons) with growth.
What does it mean to have determinate cleavage vs. indeterminate cleavage?
If a cell is removed from a 4-cell embryo, both cell balls die. It is missing important tissues because the future of the cell is already decided. Indeterminate cleavage means if a cell is removed, both cell balls will produce a complete organism and the cell future is more flexible.
