In snails, the hard calcareous shells are secreted by the
radula
ctenidium
pneumostome
mantle
Correct answer is D
No explanation has been provided for this answer.
The natural tendency of organisms as they evolve is to
decrease in size
increase in number
develop specialized structures
feed indiscriminately
Correct answer is C
No explanation has been provided for this answer.
The procaryotic cell type is characterized by a
complex cytoplasm in which different regions are poorly defined
localization of different regions of the cell into tissues
collection of organelles and macromolecular complexes
simple cytoplasm with well defined regions
Correct answer is A
No explanation has been provided for this answer.
The nucleus is considered the central organelle of a cell because it
contains the genetic material
contains the nuclear sap
is bounded by the nuclear membrane
is located at the center of the cell
Correct answer is A
No explanation has been provided for this answer.
The giraffe's long neck is used to illustrate the theory of
use and disuse
origin of species
origin of life
natural selection
Correct answer is A
The long neck of the girraffe is an example of Lamarck's theory of use and disuse.