Lethal
deadly, fatal.
Origin: L. Lethalis, from lethum = death
Of an instrument of certain death; deadly poisons; lethal weapon; a lethal injection.Of deadly proportions.
Plants and animals need elements, such as nitrogen, phosphorus, potassium, and magnesium for proper growth and development. Certain chemicals though can halt growth, e.g. herbicides in plants, or affect normal physiological activities, e.g. alcohol. For more info, read this tutorial on the effects of chemicals on plants and animals...
This tutorial looks at sex determination via the sex chromosomes, X and Y. Read it to get more info on X and Y chromosomes and the genetic traits inherited via these two...
Mutations can also influence the phenotype of an organism. This tutorial looks at the effects of chromosomal mutations, such as nondisjunction, deletion, and duplication. ..