Three lines of evidence that support the endosymbiotic theory:
1. The presence of membrane- Organelles like mitochondria and plastids have their own cell membranes, just like a prokaryotic cell does,
2. The presence of DNA- Each of these organelles have its own DNA genome, like a bacteria's genome, but much smaller.
<span>3. Reproduction (division)-Multiplication of the organelles occurs just like in bacteria, by division.</span>
Pili are the filaments that help some bacteria stick to surfaces and exchange plasmids through conjugation.
Pili are hollow, hair like appendages that are found on the surface of some bacterial cells. Pili are composed of a special protein (known as pilin). Pilia act as a means of attachment of bacteria to surfaces (such as their host) and it is also used by bacteria to exchange their genetic material (plasmids) in the mating process between cells (known as conjugation).
Answer:
the first trophic level shows a primary producer
Unlike women, men do not experience a major, rapid (over several months) change in fertility as they age (like menopause). Instead, changes occur gradually during a process that some people call andropause. Aging changes in the male reproductive system occur primarily in the testes.
