In: Biology
For each statement below, write the animal phyla from the list for which the statement is true. List as many phyla as apply to each statement.
Echinodermata (sea urchins, sea stars)
Arthropoda (insects, crustaceans, etc.)
Porifera (sponges)
Cnidaria (jellyfish, corals, sea anemones, etc.)
Chordata (vertebrae)
Has one cell layer
Has two cell layers
Has three cell layers
Are asymmetric
Are radially symmetric
Are bilaterally symmetric
Their embryos have a blastula stage
Are considered to be deuterostomes
Are considered to be protostomes
Are eukaryotic
Then, identify which of the statements from above is a characteristic that evolved more than once in animals. What does this mean?
Statement 0:- One cell layer:- None of the above
Reason:- Even the simplest member of animal kingdom is diploblastic having 2 cell layers.
Statement 1:- Has two cell layers:- Porifera, cnidaria
Reason:- Porifera and cnidaria are the simplest organisms. They are diploblastic in nature and have two germ layers ectoderm and endoderm.
Statement 2:-Has three cell layers:- Arthropods, Echinodermata, Chordates
Reason:-Arthropods, Echinodermata, and chordates are triploblastic having three germ layers ectoderm mesoderm and endoderm.
Statement 3:- Are asymmetrical:- Porifera
Reason:- Porifera have asymmetrical symmetry, their body cannot be divided into two equal halves.
Statement 4:- Are radial symmetry:-Cnidaria and Echinodermata
Reason:-The body plan of cnidaria and Echinodermata can be divided into two equal halves bypassing a line through the central axis.
Statement 5:-Bilateral symmetrical:- Chordates and arthropods
Reason:- There body can be divided into two equal halves that are mirror images.
Statement 6:- Blastula stage:- Arthropods, Echinodermata and Chordata
Reason:- Blastula stage is found in the embryo of Echinodermata, arthropods, Chordata during embryonic development.
Statement 7:-Deuterostomes:- Echinodermata and Chordata
Reason:- In deuterostomes the first opening blastopore develops into the anus. It includes bilaterally symmetrical animals like Echinodermata, hemichordate and Chordata.
Statement 8:- Protosome:- Arthropods
Reason:- In arthropods the blastocoel develops into the mouth.
Statement 9:- Eukaryotes:- All of the above phyla are eukaryotes.
Reason:- All multicellular animals starting from simpler Porifera till most complex animals like humans are eukaryotes.