Broken up rock that got eroded
Explanation:
Scientists didnt belive that there are cells untill robert hooke (1665). He observed the cells in a cork slice with the help of a PRIMITIVE microscope
Leeuwenhoek (1674), with the help of an improved microscope, discovered free living cells in pound water for the first time.
It was robert brown in (1831) who discovered the nucleus in the cell.
Purkinjie in 1839 coined the term 'protoplasm' for the fluid substance of the cell.
THE CELL THEORY, that all plants and animals are composed of cells and that the cell is the basic unit of life, was presented by two biologists, schleiden (1838) and schwann(1839). The cell theory was fuether expanded by virchow (1855) by suggesting that all cells aris form PRE-EXISTING cells. With the discovery of the electron microscope in 1940,it was possible to observe and understand the complex structure of the cell and its various organelles.
Well, thats the history of the discovery of cells.
Do you know what a pangea is well Pangea is another supercontinent the reason why we're not Pangea is because something dead which oceans with lava cools off it cools off from old to new the new rocks are pushing the consonants together and eventually and a couple of million years it will be Pangaea again
Answer:
The options are
A. secondary structure ... hydrogen bonds
B. secondary structure ... peptide bonds
C. tertiary structure ... hydrogen bonds
D. primary structure ... covalent bonds
E. tertiary structure ... covalent bonds
THE CORRECT ANSWER IS A.
A. secondary structure ... hydrogen bonds
Explanation:
The secondary structure of a polypeptide shows the localized regions of its organised structure being upheld by hydrogen bonds among the major groups
-NH and C = O
At the same time, it inhibits the hydrogen bonds of the side chains from influencing the reaction process.
The polypeptide secondary structure shows the dexterity to curl or fold as sustained by the polypeptide chains.
Answer:
n a population, more individuals are born than can survive. The available resources in nature are finite (food, water, space, etc.) and the environment is not able to support unlimited growth of a population. This causes an inevitable struggle for existence among individuals (continual struggle for existence).Explanation:
