Search Results for: primitive
Nervous System
THE is the most complicated and highly organized of the various systems which make up the human body. It is the... Read More
Abiogenesis
Definition noun plural: abiogeneses a·bi·o·gen·e·sis, eɪbaɪəʊˈdʒɛnəsɪs (1) The idea that primitive life... Read More
RNA-DNA World Hypothesis?
How did life start as we know it? In the scientific community, the "RNA World Hypothesis" has many adherents. Many believed... Read More
Cyanobacteria
Cyanobacteria Definition Cyanobacteria is a group of photosynthetic bacteria widely distributed in various aquatic habitats... Read More
Living things
Living Things Definition A living thing pertains to any organism or a life form that possesses or shows the characteristics... Read More
Geological Periods
Precambrian Times (Most Ancient) All time before life existed, Earth was still a volatile environment, though the origins... Read More
Endosymbiotic theory
A eukaryotic cell is distinct from a prokaryotic cell by the presence of membrane-bound cellular structures called... Read More
Ribonucleic acid
Ribonucleic Acid Definition noun (uncountable), ribonucleic acids ri·bo·nu·cle·ic ac·id, raɪboʊnjuːkliːɪk... Read More
Primitive Animals
Incorrect taxonomic classifications deemed organisms to be either animals or plants, in the Plantae or Animalia kingdoms... Read More
Anaerobic respiration
Anaerobic Respiration Definition What is anaerobic respiration? Anaerobic (cellular) respiration is a respiratory process... Read More
Eukaryotic cells
Eukaryotic Cells Definition What is a eukaryotic cell? Eukaryotic cells refer to the cells of (or derived from) eukaryotes,... Read More
Spontaneous generation
Definition noun plural: spontaneous generations The previously popular notion that living organisms arise or develop from... Read More
A New Theory on the Origin of Animal Multicellularity
Multicellular life, purportedly, started around 600 million years ago. From single-celled, certain organisms eventually... Read More
Dead Man Walking
Dead Man Walking: Wade Davis and the Secret of the Zombie Poison By Patrick D. Hahn Accepted on September 4, 2007 Twenty... Read More
Sieve cell
Definition noun, plural: sieve cells (botany) The main conductive cell in the phloem of the gymnosperms and... Read More
Human Reproduction
Terminology and Concepts Primary reproductive organs are called gonads - testes in the male and ovaries in the female.... Read More
Head kidney
Head kidney --> pronephros 1. The definitive excretory organ of primitive fishes. Synonym: head kidney. 2. In the embryos... Read More
Apocarpous gynoecium
Apocarpous gynoecium is comprised by the set of many simple pistils (consistig of only one carpel). Characteristic fruit for... Read More
Spermiogenesis
Spermiogenesis Definition Spermiogenesis is the stage of spermatogenesis wherein the spermatids differentiate into mature... Read More
Arthropods
There are over two million species of arthropods, who initially arrived on Earth in the middle of the Cambrian period.... Read More
Chondrichthyes
Definition noun A taxonomic class comprised of cartilaginous fish Supplement Chondrichthyes is taxonomic superclass of... Read More
Homo neanderthalensis
Definition noun Species of primitive human beings that lived between 28,000 and 300,000 years ago. Various specimens of... Read More
Binary fission
Binary Fission Definition What is binary fission? In biology, binary fission is a type of asexual reproduction where a... Read More
Intercalary meristem
The basic structural framework of plants is composed of different types of tissues. Based upon the capacity to divide, the... Read More