Their valency is one and both belong to the third period
2 because animals do not have chloroplast or a cell wall
Answer;
cells are very different but have similar properties
Explanation;
-Even though there are many different types of cells, they all share similar characteristics. All cells have a cell membrane, organelles organelles, cytoplasm, and DNA. All cells are surrounded by a cell membrane, all cells contain organelles, all cells contain cytoplasm and all cells contain DNA.
-Cells may differ in their number such that some organisms are made of only a single cell while other organisms are made of billions of cells
No 2 people in the world are "exactly alike", so the odds would be 0% chance. Twins, might be closer in alike-ness, but they still aren't "exactly alike". Hope this answered your question.
