Ontogeny – Life history of an individual. Oocyte – The encysted zygote of Plasmodium Operon – A cluster of genes whose expression is controlled by a single operator. Panspermia – Units of life in the forms of spores. Permafrost – Any ground that remains completely frozen ( °F ( °C) or colder) for at least two years straight.
These permanently frozen grounds are most common in regions with high mountains and in Earth’s higher latitudes near the North and South Poles. Phenotypic plasticity - The ability of one genotype to produce more than one phenotype when exposed to different environments. Phylogeny – Record of ancestral history. Planetesimals - Planetesimals are the fundamental building blocks of the planets as well as the ancestors of asteroids and comets.
Polypeptide chain– It consists of smaller subunits or amino acids that are linked together. They are the building blocks of proteins. Postpartum – Period of life following childbirth. XII Std Biology-Zoology Glossary XII Std Biology-Zoology Glossary Glossary Precursor– A substance from which another is formed, especially by metabolic reaction.
P rimer – A short oligonucleotide that hybridizes the template strand and gives a ’ – OH end for the initiation of nucleic acid synthesis. Probe – The probe is a single stranded DNA molecule that is ‘complementary’ to the gene of interest in a sample under study. Pseudopodia – Blunt temporary protoplasmic projections found in Amoeba or in some amoeba- like cells. Psychoactive drug - A chemical substance that acts on brain and affects the mind and behaviour of user.
Puberty – Period of reproductive maturity. Pyrolysis– Decomposition brought about by high temperatures. Recombinant– A cell or organism whose genetic complement results from recombination. Redia – Larva in the life cycle of most trematodes.
Rheoreceptors – They are receptors in fish and some amphibians that respond to water currents. Saltation – Single step large mutation. Satellite DNA – Short highly repeated eukaryotic DNA sequences, usually clustered in heterochromatin and generally not transcribed. Saltatorial – Saltatorial is an animal adapted to leaping.
They have large, muscular hindlimbs and