The statement that is true of Oparin and Haldane's theory is : the primitive organic molecules were formed in an oxidizing atmosphere in the primordial soup
This is one of the theory that determined how life on earth developed. It was one of the most influental theory on the matter
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Answer:
A relationship between unrelated organisms in which oneorganism get benefit and the other is not affected is known as commensalism.
Explanation:
In commensalism organism live in a symbiotic association. the best example is the growth of epiphytes on the top or surface of orchid plants. The epiphytes obtain nutrients from orhids while in return orchids have no benefit from epiphytic plants.
<span>The correct answer is "Absorption of rainfall by soil."
The hyrdosphere refers to all water on the earth's surface. The geosphere, in this context, refers to the solid parts of the earth (rocks, sand, etc.) Since rain is part of the hydrosphere and soil is part of the geosphere, rain soaking into the soil would be an interaction between the two. The other choices deal with changes in the hyrdrosphere, but there is no interaction with the geosphere.</span>
Answer:
a. + glucose, + lactose = On
b. - glucose, - lactose = Off
c. + glucose, - lactose = Off
d. - glucose, + lactose = On
Explanation:
Lac operon has both types of control, repressible and inducible.
Whenever glucose level is low in the cell, an enzyme known as adenylyl cyclase raises the level of cAMP which forms a dimer with CRP protein and they both act as activator of lac operon and cause expression.
Apart from this, when lactose is present in the cell, β-galactosidase enzyme metabolizes lactose to form allolactose which causes allosteric repulsion in the lac repressor and causes its removal from the operator. As soon as repressor is removed lac operon gets activated.
In wild type lac operons, the expression of lac operon occurs when glucose level is low in the cell and lactose is present but in this mutant presence or absence of glucose will not make a difference because CRP will bind Plac promoter independent of cAMP level i.e. activator CRP will work even in high glucose concentration. If lactose is present then lac operon will always express so in option 'a & d' lac operon will express but in option 'b & c' it will not express.
