Discussion:
Categorizing organisms using dichotomous key
I have already categorized the following "Groups of Organisms," except for DOLPHINS. Where would it be placed in the problem below?
bats monkeys Euglena
lemurs sponges amphibians
dolphins Ginkgo biloba jellyfish
reptiles birds beavers
echinoderms tarsiers photosynthetic bacteria
a) production of milk for the young (reproductive, physiological)
Characteristic of all mammals
b) high cognitive ability, to reason, to fasion tools (neurological)
Specific to humans
c) inability to generate carbohydrates by means of photosynthesis (metabolic)
Characteristic of all animals
d) possessing bilateral symmetry (morphological)
Characteristic of all animals
e) upright, semi-upright posture (morphological)
Specific to humans
This definition of humans excludes all primates as they lack of a high cognitive ability and cannot walk upright or in a semi-upright posture unassisted.
Problem
Most fundamental to most definning
c) inability to generate carbohydrates by means of photosynthesis (metabolic)
d) possessing bilateral symmetry (morphological)
a) production of milk for the young (reproductive, physiological)
b) high cognitive ability, to reason, to fasion tools (neurological)
e) upright, semi-upright posture (morphological)
Exclusion of animal groups by each characteristics WHERE IS DOLPHINS PLACED?
c) inability to generate carbohydrates by means of photosynthesis (metabolic)
Excludes: Photosynthetic bacteria, Euglena (a protist with chloroplast), Ginkgo biloba (tree),
d) possessing bilateral symmetry (morphological) (bilateral=left and right side that are non-identical)
Excludes: Echinoderms (starfish are radial, many sides that are identical), sponges (also radial), jellyfish (radial)
a) production of milk for the young (reproductive, physiological)
Excludes: Birds, reptiles, amphibians
b) high cognitive ability, to reason, to fasion tools (neurological)
Exludes: Bats, tarsiers, lemurs,
e) upright, semi-upright posture (morphological)
Excludes: Monkeys, Beavers
Beavers are known to use their tails as communication tools though this may be debatable characteristics included in b).