Unicellular and multicellular organisms Knowledge-Based Practice

Questions

1. 1.

   How does fatal damage to a single cell typically affect a unicellular organism compared to a multicellular organism?

   • A) It results in the death of the entire unicellular individual, whereas a multicellular organism usually survives the loss of individual somatic cells.
   • B) It triggers immediate tissue repair in the unicellular organism, whereas in a multicellular organism it causes immediate systemic collapse.
   • C) It prompts the unicellular organism to divide its remaining organelles into new cells, whereas a multicellular organism permanently loses that metabolic capability.
   • D) It causes only minor localized damage to the unicellular organism, whereas in a multicellular organism any single cell death is fatal to the entire body.
2. 2.

   In unicellular organisms, cell division directly serves which of the following primary functions, in contrast to somatic cell division in multicellular organisms?

   • A) Differentiation into specialized tissues
   • B) Repair and replacement of damaged body tissues
   • C) Increase in the overall body size of an individual
   • D) Asexual reproduction of the entire organism
3. 3.

   Which factor primarily limits the maximum size of a single-celled organism and necessitates multicellular organization for large bodies?

   • A) Nuclear DNA degrades rapidly when the volume of cytoplasm exceeds microscopic dimensions.
   • B) The surface area of the plasma membrane increases more slowly than the internal volume, restricting material exchange.
   • C) Structural proteins cannot maintain a lipid bilayer across an area larger than a single microscopic cell.
   • D) Cytoplasmic enzymes require signals from neighboring cells to sustain basic metabolic reactions.
4. 4.

   What is a major consequence of cellular specialization and the division of labor in complex multicellular organisms?

   • A) Every individual cell performs all metabolic functions required for its independent survival.
   • B) Organisms lose the ability to maintain homeostasis through coordinated tissues and organs.
   • C) Specialized cells become interdependent and rely on other cell types to sustain life.
   • D) Differentiated cells permanently eliminate unexpressed genes to optimize cellular division.
5. 5.

   Which statement correctly describes a fundamental distinction between unicellular and multicellular organisms?

   • A) Unicellular organisms cannot reproduce independently, whereas multicellular organisms reproduce through specialized organ systems.
   • B) Unicellular organisms are composed exclusively of prokaryotic cells, whereas multicellular organisms lack cellular differentiation.
   • C) Unicellular organisms require colonial aggregation to survive, whereas multicellular organisms consist of independent, non-interacting cells.
   • D) A single cell carries out all vital life activities in unicellular organisms, whereas multicellular organisms depend on specialized cells exhibiting a division of labor.

Answers and step-by-step solutions appear after you finish the test.