Answer:
Option D, the "biological ladder"
Explanation:
The food chain is the network of organism in which all are dependent on each other for their food, energy source and survival.
The circle of life depicts the time frame starting from origin of a life form till its death and the intermediate stages.
The tree of life basically determines which organism has evolved from which other organisms.
The biological ladder represents the development of species from simple form to a much complex form.
Hence, option D is the right metaphor
Answer:Enrico must multiply the distance of mars from sun (meters) with the 
to convert the distance in astronomical units.
Explanation:
1 astronomical unit = 
Let the distance between the sun and Mars be Y( meters)
Distance in AU= 
Enrico must multiply the distance of mars from sun (meters) with the to convert the distance in astronomical units.
Plankton is the organisms that form the base of most open ocean food webs because fish eat plankton and bigger fish like sharks eat the little fish that eats the plankton.
Answer:
Explanation:
Sunlight is needed for photosynthesis because the solar energy is what is converted to chemical energy by the plant's chloroplasts. This energy is necessary for the production of glucose, which provides usable energy for the plant. the energy convertion turns solar energy into chemical energy
