Answer:
1. True
Proteins are frequently called the building blocks of life because they are found everywhere: in our cells, bones, muscles, blood, hormones, enzymes and more. It is thanks to proteins that our body has any sort of structure to it.
2.False
Tissues are groups of similar cells that have a common function. An organ is a structure that is composed of at least two or more tissue types and performs a specific set of functions for the body. Many organs working together to accomplish a common purpose is called an organ system.
3. False
Prokaryotes are unicellular organisms that lack organelles or other internal membrane-bound structures. Therefore, they do not have a nucleus, but, instead, generally have a single chromosome: a piece of circular, double-stranded DNA located in an area of the cell called the nucleoid.
4. False
False, blood cells don't have a rigid cell wall. Plants and Bacteria have rigid cell walls, but not blood cells!