Unicellular and multicellular organisms Knowledge-Based Download PDF

Questions

1. 1.

   Why do complex multicellular organisms require specialized internal transport systems to distribute nutrients and gases, whereas unicellular organisms can survive without them?

   • A) Most cells in complex multicellular organisms are separated from the external environment and cannot rely on direct diffusion across the organism's surface.
   • B) Unicellular organisms possess internal organ systems that eliminate the necessity of direct membrane diffusion with their surroundings.
   • C) Individual cells within multicellular organisms lack the semipermeable membranes required for passive and active substance transport.
   • D) Multicellular organisms maintain a significantly higher whole-body surface area-to-volume ratio than microscopic single-celled organisms.
2. 2.

   How does the biological process of organismal growth fundamentally differ between unicellular and multicellular organisms?

   • A) Unicellular organisms grow primarily by increasing their total number of cells, whereas multicellular organisms increase in size solely through the enlargement of existing cells.
   • B) Unicellular organisms grow primarily through an increase in individual cell volume, whereas multicellular organisms achieve growth mainly by increasing their total number of cells through division.
   • C) Multicellular organisms grow solely by accumulating non-cellular extracellular matrix without undergoing cell division, whereas unicellular organisms duplicate internal nuclei to grow.
   • D) Unicellular organisms grow by assembling neighboring independent cells into a single body, whereas multicellular organisms grow by reducing their overall cell volume.
3. 3.

   In multicellular organisms, individual cells undergo specialization to perform distinct physiological roles. Which of the following is a direct consequence of this cellular division of labor?

   • A) Each somatic cell maintains the capability to survive independently in isolation from the organism.
   • B) Distinct cell lineages within the same individual develop fundamentally different genomic DNA sequences.
   • C) The metabolic rate of individual cells becomes entirely unaffected by diffusion limitations.
   • D) Specialized cells become interdependent, relying on the coordinated activities of other cell types to sustain life.
4. 4.

   Which of the following characteristics is unique to multicellular organisms and cannot be exhibited by unicellular organisms?

   • A) Synthesis of proteins using intracellular ribosomes
   • B) Regulation of internal homeostasis through metabolic pathways
   • C) Differentiation of cells into specialized tissues that carry out dedicated functions
   • D) Replication of genetic material prior to cell division
5. 5.

   Which of the following statements correctly describes a key functional difference between unicellular and multicellular organisms?

   • A) Unicellular organisms rely on specialized organ systems to maintain homeostasis, whereas multicellular organisms perform all life processes within a single independent unit.
   • B) Multicellular organisms depend on cellular differentiation and division of labor, whereas a unicellular organism must carry out all essential life processes within one cell.
   • C) Unicellular organisms are composed exclusively of eukaryotic cells, whereas multicellular organisms consist entirely of simpler prokaryotic cells.
   • D) Multicellular organisms can survive if any single cell is separated from the group, whereas individual unicellular organisms cannot survive in isolation.