Bacterial Morphology Flashcards

Questions and Answers

What is the morphology of cocci?

Spheres (correct)

Clusters

Rods

Spirals

What is the definition of bacilli?

Rods

Which terms describe the arrangement of bacterial cells?

Diplo

Strepto

Tetrad

All of the above (correct)

What does 'pleomorphic' mean?

Organisms that exhibit growth in a variety of shapes. Signup and view all the answers

Match the bacterial terms with their definitions:

Diphtheroids = Any bacterium of a genus that includes the diphtheria bacillus Palisades = Arranged like 'Chinese letters' due to unique division Akinetes = Resting cells with thick walls formed during adverse conditions Heterocyst = Cells involved in nitrogen fixation Signup and view all the answers

Spirilla and spirochetes are flexible and have motility through axial filaments.

False Signup and view all the answers

Differentiate between heterotrophic eubacteria and cyanobacteria.

Cyanobacteria do not have a nucleus, photosynthesize, and live in water; heterotrophic eubacteria get energy from other sources. Signup and view all the answers

The size of an object viewed through a microscope is determined by the formula: Size = calibration x ___ dimension.

ocular Signup and view all the answers

What are the characteristics of heterocysts in cyanobacteria?

Both A and C Signup and view all the answers

Study Notes

Bacterial Morphology Overview

Prokaryotic cells exhibit common shapes including cocci (spheres), bacilli (rods), and spirilla (spirals).
Cell arrangements include diplo (pairs), strepto (chains), tetrads (cubical packets), sarcina (3 planes), and staph (clusters like grapes).

Morphological Terminology

Bacterial morphology includes terms such as cocci, bacillus, and spirilla.
Common arrangements of bacteria are categorized as tetrad, staph, and strep.

Cell Division and Arrangement

Division along a single plane generates pairs (dip-) or chains (strep-).
Division in 2 or 3 planes results in tetrads, while irregular divisions create clusters (staph-).

Special Bacterial Forms

Diphtheroids refer to bacteria associated with diphtheria, causing respiratory diseases.
Palisades display characteristic angular arrangements due to outer cell wall division.
Spores are resilient forms that bacteria adopt in adverse conditions for survival.

Spirilla vs. Spirochetes

Spirilla are rigid, utilizing polar flagella for movement; spirochetes are flexible, moving via axial filaments.

Pleomorphic Bacteria

Pleomorphic organisms can exhibit various shapes, often seen in preparations that cannot be easily classified.

Heterotrophic Eubacteria vs. Cyanobacteria

Cyanobacteria are unicellular, lack a nucleus, and are photosynthetic; they produce their own food in aquatic environments.
Heterotrophic eubacteria obtain energy through the respiration and fermentation of organic matter from plants and animals.

Akinete and Heterocyst in Cyanobacteria

Akinetes function as resting cells, formed in response to harsh environments, featuring thick walls and nutrient storage.
Heterocysts are specialized cells for nitrogen fixation, requiring anoxic conditions to prevent oxygen inhibition.

Microscope Calibration and Size Measurement

To determine the size of an object through a microscope, multiply the calibration factor by the ocular dimension (10X).
Size estimation varies by objective: 10 nanometers (low), 2.5 nanometers (high), and 1 nanometer (oil).

Description

Test your knowledge on the various shapes and arrangements of prokaryotic cells. This quiz covers cocci, bacilli, spirilla, and more, helping you identify and draw these common morphologies. Enhance your understanding of bacterial classification and relationships.