Anatomical Orientation and Systems

• The following topics relate to anatomy and evolution:

Anatomical Orientation and Systems

• Dorsal refers to the back or upper side, while ventral refers to the front or lower side.
• Anterior means toward the front, while posterior means toward the back.
• Open circulatory systems involve hemolymph bathing the organs directly, whereas closed circulatory systems have blood contained in vessels.
• Cold-blooded (ectothermic) organisms rely on external sources for body heat, while warm-blooded (endothermic) organisms maintain a constant internal body temperature.
• Bilateral symmetry is a body plan where the left and right sides are mirror images.
• The purpose of the nervous system is to transmit signals for coordination and response.
• Sexual reproduction in the animal kingdom serves to increase genetic diversity.
• Organs such as the esophagus, intestines, and brain have specific digestive, nutrient absorption, and processing functions.
• A 3-chambered heart has two atria and one ventricle, while a 4-chambered heart has two atria and two ventricles, for more efficient circulation.
• The internal skeleton is inside the body, and an exoskeleton is outside the body.
• Testes are the male reproductive organs, while ovaries are the female reproductive organs.
• Nerves transmit electrical signals and the spinal cord relays signals from the brain.
• Kidneys filter waste from the blood and lungs facilitate gas exchange.

Taxonomy and Evolution

• Taxonomy involves classifying and naming organisms.
• Phylogeny studies the evolutionary relationships among organisms.
• Classification tools such as cladograms and dichotomous keys are used to identify and categorize species.
• Physical adaptations are structural features, while behavioral adaptations are actions that aid survival.
• Natural selection drives evolution by favouring advantageous traits.
• Natural selection occurs without human intervention, while artificial selection involves human intervention.
• Species and speciation is how new biological species arise.
• Isolation that results in speciation can lead to increased biodiversity.
• Mutations and recombination during genetic change introduce genetic variation.
• Homologous structures indicate common ancestry due to shared anatomical features.
• Vestigial traits are remnants of structures that had a function in ancestors.
• Overproduction, competition, and variation influence natural selection and evolution.

Learn about anatomical orientation terms like dorsal and ventral, anterior and posterior. Explore open and closed circulatory systems, cold-blooded versus warm-blooded organisms, and bilateral symmetry. Understand the nervous system's role and sexual reproduction's importance in genetic diversity.