71 results found

Search Results for: primitive

Primitive

primitive Undeveloped or in early stages of development,... Read More

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 theory postulating that... Read More

Life

Life Definition noun, plural: lives (1) A distinctive characteristic of a living organism from dead organism or non-living... Read More

Protist

Protist Definition What is a protist? All protists are eukaryotes, i.e. organisms with a nucleus. However, they are... 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

Fish

While insects and similar types of organisms strived to occupy land, the sea was teeming with life aiming to secure their... Read More

Geological Periods

Precambrian Times (Most Ancient) All time before life existed, Earth was still a volatile environment, though the origins... Read More

Cyanobacteria

Cyanobacteria is a phylum comprised of photosynthetic bacteria that live in aquatic habitats and moist soils. Others are... Read More

Endosymbiotic theory

Endosymbiotic theory definition noun (evolutionary biology) A theory suggesting that the organelles such as mitochondria... Read More

Ribonucleic acid

Ribonucleic Acid Definition noun (uncountable), ribonucleic acids ri·bo·nu·cle·ic ac·id, raɪboʊnjuːkliːɪk... Read More

Monotreme

Definition noun (zoology) Any of the egg-laying mammals belonging to the taxonomic group, Monotremata Supplement The class... Read More

Epiblast

Definition noun (embryology) The outer (upper) ectodermal layer of the embryonic disc, closer to the amniotic cavity, and... Read More

Primitive Animals

Incorrect taxonomic classifications deemed organisms to be either animals or plants, in the Plantae or Animalia kingdoms... Read More

Living things

Living Things Definition A living things pertains to any organism or a life form that possesses or shows the... Read More

Eukaryotic cells

Eukaryotic Cells Definition What is a eukaryotic cell? The term “cell” is a common word in biology, anatomy, and... Read More

Prosimian

Definition noun, plural: prosimians Any of the primitive, nocturnal primates, such as lemurs, lorisoids, haplorrhine... 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

Prokaryote

Prokaryote refers to any of the group of organisms primarily characterized by the lack of true nucleus and other... Read More

Spontaneous generation

Definition noun plural: spontaneous generations The previously popular notion that living organisms arise or develop from... Read More

Sieve cell

Definition noun, plural: sieve cells (botany) The main conductive cell in the phloem of the gymnosperms and... Read More

Animal

Animal Definition An animal (plural: animals) refers to any of the eukaryotic multicellular organisms of the biological... 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

Apocarpous gynoecium

Apocarpous gynoecium is comprised by the set of many simple pistils (consistig of only one carpel). Characteristic fruit for... Read More

Chondrichthyes

Definition noun A taxonomic class comprised of cartilaginous fish Supplement Chondrichthyes is taxonomic superclass of... Read More

Head kidney

Head kidney --> pronephros 1. The definitive excretory organ of primitive fishes. Synonym: head kidney. 2. In the embryos of... Read More

Spermiogenesis

Spermiogenesis definition Spermiogenesis is the stage of spermatogenesis wherein the spermatids differentiate into mature... Read More

Red algae

The red algae belong to the phylum Rhodophyta which literally was derived from the Greek word ῥόδον (rhodon), meaning... 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

Homo neanderthalensis

Definition noun Species of primitive human beings that lived between 28,000 and 300,000 years ago. Various specimens of... Read More

Polyphyletic

Definition adjective Taxonomic groups that have similar character states that descends from one or more ancestral... Read More

Leptomonad

Definition noun (protozoology) The common name for any of the member of the genus Leptomonas Supplement Leptomonads refer to... Read More

Archamoebae

Definition noun A taxonomic class in Phylum Amoebozoa characterized by the absence of mitochondria Supplement Archamoeba... Read More

Simian

Definition noun, plural: simians Any of the placental primates, particularly hominins, apes and... Read More

Sieve element

Definition noun (botany) A food-conducting cell in the phloem of vascular plants Supplement The phloem is the vascular... Read More

Sieve tube

Definition noun, plural: sieve tubes (botany) Any of the tubes in the phloem comprised of cells joined end-to-end through... 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

Arthropods

There are over two million species of arthropods, who initially arrived on Earth in the middle of the Cambrian period.... Read More

Human Reproduction

Terminology and Concepts Primary reproductive organs are called gonads - testes in the male and ovaries in the female.... Read More

Subgerminal cavity

subgerminal cavity --> primitive gut A flat sheet of intraembryonic endoderm that will change into a tubular gut due to... Read More