SCI1186 Lecture Notes - Lecture 2: Symmetry In Biology, Convergent Evolution, Gas Exchange
16 Jun 2018
School
Department
Course
Professor
Week 2 – “Meet the Animals”
CHARACTERISTICS OF ANIMALS
Heterotrophic: An organism that doesn’t make its own food (all animals)
Autotrophic: An organism that makes its own food (all plants)
Lack cell walls
Most have muscle and nerve cells
Most reproduce sexually
All animals are multicellular
Anatomy: structure of an animal
• Radial symmetry
o An organism can be cut in half from any angle and still be symmetric (Anemones, Jelly Fish)
• Bilateral symmetry
o An organism can be cut in half from one direction and is symmetrical (Humans)
• Specialised organs
o
Physiology: chemical and physical processes necessary for survival
Convergent evolution: Unrelated species having similar characteristics (seals, dolphins, sharks, penguins are shaped
like a torpedo to swim faster
Summary:
While animals may look completely different from each other, all animals are multi-celled heterotrophic organisms, that have
chemical and physical processes.
The similarities between features of different animals are the result of evolution to aid the species and how it interacts with its
environment.
Document Summary
Heterotrophic: an organism that doesn"t make its own food (all animals) Autotrophic: an organism that makes its own food (all plants) An organism can be cut in half from any angle and still be symmetric (anemones, jelly fish) An organism can be cut in half from one direction and is symmetrical (humans) Physiology: chemical and physical processes necessary for survival. Convergent evolution: unrelated species having similar characteristics (seals, dolphins, sharks, penguins are shaped like a torpedo to swim faster. While animals may look completely different from each other, all animals are multi-celled heterotrophic organisms, that have chemical and physical processes. The similarities between features of different animals are the result of evolution to aid the species and how it interacts with its environment. In order for diffusion to work, the organism can be no more than three cells thick. However, it is mostly used by single-celled organisms. Transporting carbon dioxide (co2) and oxygen with the blood.
