biotechnogeek

DNA replication 1) Watson and Crick proposed double helical structure of DNA. The also postulated a scheme for DNA replication. 2) in DNA replication scheme proposed suggested that the two strands would separate and act as a complete for the sentences of new complementary strands.  3) after completion is DNA molecule would have one parental and one newly synthesized strand. This scheme of replication is called as semiconservative DNA replication.  4) this means that DNA replication is semi conservative in nature in such model one parental strand remains as it is and give space to formation of other DNA strand.  5) resultant and DNA strand becomes hybrid that is contains one parental and other newly synthesized DNA strand.  The experimental proof:- 1) it is proven that DNA replication is semiconservative in nature and is first shown in the is Escherichia coli and subsequently in higher organisms such as human and plant cell.  2) Matthew meselso...

 Ecological pyramids :- 1) Pyramid shape is such that base of a pyramid is broad and narrows down towards the apex.  2) the base of each pyramid represents the producers or the first trophic level whereas The Apex or tip represents tertiary or top level consumer.  3) the usually studied types of pyramids are Pyramid of number Pyramid of biomass  pyramid of energy Any species can occupy more than 1 position in trophic level in some ecosystem at the same time. Example of sparrow  inmost ecosystems all the pyramids of number, Biomass and energy are more while herbivores are list and carnivores very less . And energy of lower level is higher as that of higher level.  Exception is tree and insects while Biomass of sea is also inverted.  Pyramid of energy is always upright and can't be inverted because energy is always gets loosed from one tropical level to other and to other While energy lost is of heat.  Each bar represents energy of pyramid the...

 Ecosystem-1:-                            Ecosystem is a functional unit of nature in which one organism interacts with others and environment. Ecosystem is divided in two categories aquatic and terrestrial.There ae some man made ecosystems as crop field and aquarium. Ecosystem :- Structure and function                             Vertical distribution of different species occupyingdifferent levels is known as Stratification .Ecosystem function asa unit in  1) Productivity 2) Decomposition  3) Energy flow 4) Nutrient cycle                               An example which includes all is Pond                              Pond is a shallow body    in which all the above ment...

                           Normally egg cell develops into zygote  after fertilization by male gamate.In this normal fertilization after fertilization zygote formation occurs and egg develops into organism.                            While one unusual method is followed by some insects and lizards aphids and aves in which egg develops into organism without fertilization is known as Parthenogenesis .There are various organisms which develops without fertilization through parthenogenesis, this organisms are called as Parthenogenone or Parthenote. eg desert lizards and some insects                            There are some intermediate condithions in parthenogenesis and fertilization example Partial parthenogenesis,  gynogenesis, androgenesis. 1) Partial parthenogene...