1. explain what the ""biological species"" definition is. describe its strengths and weaknesses. 2. why does a biological species have to be reproductively isolated from other organisms? 3. compare allopatric and sympatric speciation. 4. briefly explain the following species barriers a. habitat isolation b. temporal isolation c. behavioral isolation d. mechanic isolation e. gametic isolation f. reduced hybrid viability g. reduced hybrid fertility h. hybrid breakdown 5. compare the concepts of gradualism and punctuated equilibrium.

ans.

gregor john mendel is known for study of inheritance in pea plants. he used garden pea plant for his study, having alternative traits for various characters. he performed cross-breeding in pea plants to check how characters are transmitted between parents to offspring, such as cross between pure tall and pure dwarf plant. mendel studied the inheritance patterns in pea plants for various generations.

thus, the correct answer includes options and f).

not only is it colder, it also becomes darker, less salty, and more dense.

la transducción de señal ocurre cuando una molécula de señalización de fluido extracelular activa un receptor de superficie de la célula.