Search results
Results from the WOW.Com Content Network
Diagram in Darwin's On the Origin of Species, 1859. It was the book's only illustration. The letters A–L represent distinct descents. Each horizontal line represents 1000 generations. Descent A has 3 existent species after 10000 generations. Descent I has 2. Descents E, F have 1 each. The other descents have gone extinct.
Standard anatomical terms of location are used to describe unambiguously the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on.
Anatomy is a "branch of morphology that deals with the structure of organisms". [8] Molecular morphology is a rarely used term, usually referring to the superstructure of polymers such as fiber formation [9] or to larger composite assemblies. The term is commonly not applied to the spatial structure of individual molecules.
A cladogram (from Greek clados "branch" and gramma "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be ...
The vaginal process forms a gradually elongating pouch, which eventually reaches the bottom of the scrotum, and behind this pouch, the testicle is drawn by the growth of the body of the fetus, for the gubernaculum does not grow proportionately with the growth of other parts, and therefore the testicle, being attached by the gubernaculum to the ...
Anatomy is often described in planes, referring to two-dimensional sections of the body. A section is a two-dimensional surface of a three-dimensional structure that has been cut. A plane is an imaginary two-dimensional surface that passes through the body. Three planes are commonly referred to in anatomy and medicine: [1] [2]: 4
Diagram of a typical insect leg The typical and usual segments of the insect leg are divided into the coxa, one trochanter , the femur, the tibia, the tarsus, and the pretarsus . The coxa in its more symmetrical form, has the shape of a short cylinder or truncate cone, though commonly it is ovate and may be almost spherical.
Segmentation in biology is the division of some animal and plant body plans into a linear series of repetitive segments that may or may not be interconnected to each other. This article focuses on the segmentation of animal body plans, specifically using the examples of the taxa Arthropoda , Chordata , and Annelida .