Question

• What characteristics define a eukaryote?
  • How do they fit into the tree of life?
  • What are the advantages of a dynamic cytoskeleton and endomembrane system?
  • How does eukaryotic DNA organization differ from prokaryotic?
    • How does DNA replication differ?
    • What advantages/disadvantages are there for each kind of replication?

these are the questions i cannot answer on my study guide, thank you for the help.

Answer 1

the eukaryote bears following chaaracterstics-

· Cytoskeleton consisting of tubulin-based microtubules and actin-based microfilaments, and ancestrally including motile cell extensions called ‘flagella’ or ‘cilia’ that contain an axoneme of 9 peripheral microtubular doublets and 2 central microtubules.

· An endomembrane system that consists of endoplasmic reticulum, Golgi bodies, vacuoles, lysosomes, peroxisomes, and the nuclear envelope.

· Primary genome of each cell consisting of multiple linear chromosomes contained within a membrane-bound nucleus.

· Mitochondria - organelles with diverse functions, usually including aerobic respiration, iron sulfur cluster assembly, and synthesis and breakdown of small molecules such as lipids and amino acids. Mitochondria are bounded by two membranes, and usually contain a small genome. They are the descendents of an alpha-proteobacterial endosymbiont.

· Translation machinery in the form of 80S ribosomes, each consisting of four molecules of RNA complexed with many proteins, and partitioned in a small (40S) and a large (60S) subunit