Cell divison is necessary to replace cells that are worn and aging. Cells do not have an indefinite life span. Fo example, the life span of a red blood cell is about 120 days.
Some algae have chloroplasts and chlorophyll and obtain their energy through photosynthesis while some algae like euglena are both heterotrophic (decompose dead organic matter) and autotrophic (use photosynthesis) and can also obtain energy likewise.
The answer is D, Because dinosaurs appears in the Triassic period while insects appeared in the Devonian period which is about 160 million years about, which rules out A and B. Humans have been on Earth for almost 3 million years, which is nothing compared to the history of life in earth, which about 4,000 million years of life history, so D
Phylum Porifera
The phylum Porifera ("pore-bearing") consists of approximately 5,000 species of sponges. These asymmetrical animals have sac-like bodies that lack tissues, and are usually interpreted as representing the cellular level of evolution
Answer:Institutional Animal Care and Use Committees ( IACUC).
Explanation: it was formally introduced in 1986 with an amendment to the Animal Welfare Act and corresponding changes in U. S. public health service policy. It is the committee that investigates researcher to know if they are properly trained to perform animal procedures, as required by law.
