Rock Cycle
here’s my cell theory notes

In biology, cell theory is a scientific theory first formulated in the mid-nineteenth century, that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells. Cells are the basic unit of structure in all organisms and also the basic unit of reproduction.

The three tenets to the cell theory are as described below:

All living organisms are composed of one or more cells.

The cell is the basic unit of structure and organization in organisms.

Cells arise from pre-existing cells.

The theory was once universally accepted, but now some biologists consider non-cellular entities such as viruses living organisms, and thus disagree with the first tenet. As of 2021: "expert opinion remains divided roughly a third each between yes, no and don’t know".As there is no universally accepted definition of life, discussion will continue.

Explanation:

answer:   option a) glucagon was secreted by his pancreas before he ate the cookies because blood glucose was low. insulin was secreted after he ate the cookies because his blood glucose was high.

explanation: