There are a couple of words that I get a little confused because they have the same suffix -‘-lecithal’. This suffix is derived from the Greek word lekithos which means ‘having yolk of an egg’. It would be easy to remember these terms from there etymology.
Isolethical :
Derived from Greek isos which means EQUAL
Having the yolk distributed EQUALLY throughout the egg
In mammals, sea urchins, snails etc.
Mesolethical:
Derived from Greek mésos which means middle
Having an intermediate amount of yolk
In amphibians
Telolethical
Derived from Greek telos which means NEAR
Having the yolk NEAR one end of the egg, hence uneven distribution of yolk
Found in birds, reptiles, and fish.
Centrolethical
Centro --> CENTER
Having the yolk near the CENTRE of the egg
In arthropods
Alethical:
Relating to an egg with little or NO yolk
References: Quinion, Michael. "Affixes: -lecithal." Affixes: the Building Blocks of English (2008). Received: Nov. 2010.
This is an animal or plant with both which have both the reproductive organs of a male and female. A person who is a hermaphrodite (also known as intersex) has ovarian and testicular tissues and has the sexual characteristics of a male and female. This is a rare condition. At birth, their sex determination is ambiguous.
The etymology behind this word is very interesting as it has originated from a Greek myth. Hermaphródītos was the son of Hermes (messenger of the Greek gods) and Aphrodite (Greek goddess of love). A water nymph – Salmacis, was fervently in love with Hermaphródītos that she prayed to the gods to be in complete union with him. Consequently, their bodies merged into one hence forming a person with both sexual characteristics.
Reference:
"Hermaphrodite - Word Origin and History." Word-Origins.com – History and Etymology of Words. 2010. Web. Sept. 2010. .
Developmental Biology classes began last week, and there are already words popping up which I get confused on because they appear so similar. The terms below are all derived from the Greek word blastos (βλαστός) – which means ‘sprout’.
Blastomeres: These are the cells formed from the mitotic divisions – during cleavage- of the zygote (fertilized egg). The divisions continuously occur to form the morula.
Blastula: This is a spherical body with a fluid-filled cavity which is developed from the morula stage. This is also known as blastosphere.
Blastocoel: This is the fluid filled cavity of the blastula.
Blastoderm: This is the single layered wall of cells of the blastula.
Blastocyst: This structure is present in the early embryonic development. It is thin-walled and hollow – contains a group of cells (inner cell mass). The embryo – tissues of the body - develops from the inner cell mass. The placenta and other supporting tissues required for the development of the fetus inside the uterus arises from the outer layer of the blastocyst (trophoblast).
Blastopore: At the gastrula stage, this is the invagination of the blastula which forms the opening of the archenteron. The archenteron is the central cavity of the gastrula, which develops into the intestinal or digestive cavity.
References:
"Blastomere - Definition of Blastomere in the Medical Dictionary - by the Free Online Medical Dictionary, Thesaurus and Encyclopedia." Medical Dictionary. 2009. Received. 10 Sept. 2010. .
"Blastula - Definition of Blastula in the Medical Dictionary - by the Free Online Medical Dictionary, Thesaurus and Encyclopedia." Medical Dictionary. 2009. Web. 10 Sept. 2010. .
"Blastocyst Definition - Medical Dictionary Definitions of Popular Medical Terms Easily Defined on MedTerms." 2003. Web. 10 Sept. 2010. .
"Blastopore - Definition of Blastopore in the Medical Dictionary - by the Free Online Medical Dictionary, Thesaurus and Encyclopedia." Medical Dictionary. 2007. Web. 10 Sept. 2010. .
"Archenteron - Definition of Archenteron by the Free Online Dictionary, Thesaurus and Encyclopedia." Dictionary, Encyclopedia and Thesaurus - The Free Dictionary. 2009. Web. 10 Sept. 2010.
