He first divided all living organisms in 2 groups
Animal or Plant
He then put these into subgroups
Animal subgroups: land, water, air
Plant subgroups, small medium or large
Not a very specific approach to taxonomy but it was used for well over 100 years
Answer:
n stage 13, all four limb buds are present. In stage 13, the upper limb buds resemble flippers. In stage 23, the upper limb shows well-formed arm, elbow, wrist, and fingers. In stage 23, the lower limb shows well-formed toes, feet, and knees.
Explanation:
The variable that researchers manipulate is the independent variable.
The reason for this is because in experiments different manipulations are often introduced. The sole purpose of these manipulations is to see whether they will affect our independent variable and if they will change its value.
