Sponges, members of the Porifera, might be the simplest multicellular
animals on Earth. They do not have any tissues, organs, or organ systems. In
order for sponges to have evolved, what MUST have happened first?
the organization of cells into groups
symbiotic relationships among various cells
the evolution of cells with nuclei and organelles
the development of the cell wall as a protective mechanism
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Ces as a System

tsd is temerature dependent sex determination.

tsd: it is a type of environmental sex determination in which the temperature experienced during embryonic/ larval development (ambient temperature for development) determine the sex of the offspring.

crocodile displays the tsd where the ambient temperature of the developing egg determines the individual's sex. for example in the american alligator's eggs, incubation at 33 ºc produces mostly males, while incubation at 30 ºc produces mostly females. so if the american alligator's egg will get the ambient temperature (33 degree celcius)during embryonic development from egg, the offspring will be male and same for the female sex determination.

lunar landing mission. apollo 11 was the first manned mission to land on the moon. the first steps by humans on another planetary body were taken by neil armstrong and buzz aldrin on july 20, 1969. the astronauts also returned to earth the first samples from another planetary body.

explanation: