In geology, a graded bed is one characterized by a systematic change in grain or clast size from one side of the bed to the other. Most commonly this takes the form of normal grading, with coarser sediments at the base, which grade upward into progressively finer onesI just learned about this in our rocks and minerals unit for science, 
 
        
             
        
        
        
<h3><u>Answer and Explanation;</u></h3>
- <u>Endosymbiotic theory</u> explains the origin of chloroplasts and mitochondria and their double membrane.  Mitochondria of eukaryotes evolved from aerobic bacteria living within their host cell and the chloroplasts of eukaryotes evolved from endosymbiotic cyanobacteria. 
- On the other hand according to the <u>autogenous hypothesis, </u>mitochondria and chloroplasts have evolved within the protoeukaryote cell by compartmentalizing plasmids or vesicles of DNA within a pinched off invagination of the cell membrane. 
- <u>Endosymbiont theory </u>is the theory that suggests that simple prokaryotic cells were engulfed by larger prokaryotes 1.5 billion years ago.
- <u>Autogenous theory</u> is a theory that was proposed as an alternative to endosymbiont theory. proposes that eukaryotic organelles formed by infolding of the plasma membrane.
- <u>Horizontal gene transfer theory</u> is an alternative to endosymbiont and autogenous theories for the origin of complex organelles in eukaryotes.
 
        
        
        
All living organisms need to take substances from their environment to obtain energy, to grow and to stay healthy
        
             
        
        
        
Answer:
the answer is c. it has both DNA and RNA
 
        
             
        
        
        
Answer:
I. Cell capsule
II. Cell wall
III. Plasma membrane
IV. Nucleoid
V. Cytoplasm
Explanation:
In the structure of bacterium, I represent Cell capsule which is the outer covering of bacterium cell, II is the Cell wall that is located after the cell capsule. III is the Plasma membrane which is also called cell membrane which is the second boundary of cell. IV represents Nucleoid which like nucleus having genetic material, V is Cytoplasm that is responsible for the transportation medium for various nutrients..