Answer:
C
Explanation:
The cell wall in only present in plant cells, not animal cells. Hence, the fact that plant cells are rectangular while animal cells are more circular.
Over time, as oxygen levels decrease, CO2 levels increase. Respiration is correct as it uses oxygen as a reactant and releases CO2 as a byproduct.
paleontology is the study of fossils whilst archaeology is the study of human remains and artefacts
Homozygous is the same heterozygous is different. Such as TT and tt are homo and Tt is heterozygous.