Question

Indicate whether the following statements are true (T) or false (F).

A.	Unicellular organisms have a one-celled body.	(T/F)
B.	Muscle cells are branched.	(T/F)
C.	The basic living unit of an organism is an organ.	(T/F)
D.	Amoeba has an irregular shape.	(T/F)

Answer 1

Hint: The unicellular organisms are the most primitive type of organisms. They have a very simple body design composed of a single cell like bacteria. The muscles are soft tissue composed of actin and myosin filaments. These filaments form cross-bridges. The organism can be single-celled or multi-celled. The organs are made of tissues that further are made of small units. Amoeba is a unicellular organism that can modify its shape.

Complete answer:
Let us understand each given statement to derive the right answers.

Statement A: Unicellular animals are those that are made up of a single unit called a cell. These are usually prokaryotic organisms. They have a simple body design as compared to the multicellular organism. The single-cell performs all the desired functions required for survival in a unicellular organism. An example is E.coli. It is a bacteria consisting of a single cell that performs the functions of feeding, reproduction, digestion, and excretion. So, this statement is true (T).
Statement B: Muscles are a type of soft tissue made up of two major components called actin and myosin filaments. These protein filaments slide past one another. This cross-bridging allows the muscle to contract to allow changes in length and shape. They are spindle-shaped rather than being branched. The muscle cells are of three types including skeletal muscles, cardiac muscles, and smooth muscles. The cells of cardiac muscles are somewhat branched. But it is not true for the whole muscle term. The nerve cells are branched. Hence, this statement is false (F).
Statement C: The basic living unit is a cell, not an organ in an organism. The body is made up of organ systems composed of different organs working for different functions. The organs further are made of tissues. The tissues consist of clusters of cells. The cells are the basic functional units of the whole body. They perform all the required metabolic and catabolic activities that regulate tissues. The tissues further function to regulate organs and organs work in sync making the organ system. So, this statement is also false (F).
Statement D: Amoeba is a single-celled organism that can modify its shape greatly due to a jelly-like structure. It is shaped like a splash of ink having an irregular body. The Amoeba forms a large group of unicellular eukaryotic organisms. Thus, this statement is true (T).

Note: Each of the specific organisms has its characteristic structure and functions. But the cells are the fundamental and basic units of life. The most primitive life is thought to be initiated from single-celled organisms. The unicellular organism has a special ability to survive in the harshest conditions. Multicellular organisms are made of millions of cells and thus are more complex than unicellular organisms. Also, they have different specific units to perform a particular function.