Answer:
A neuron's nucleus is located in its CELL BODY
A nerve impulse moves toward a neuron's cell body along AXON
Explanation:
A neuron consists of three major parts: cell body, dendrite and the axon.
1) The cell body consists of the nucleus and cytoplasm
2) Dendrites are short cytoplasmic filaments which conduct impulses towards the cell body
3) Axon is made up of a single, long fibre which transmits impulses away from the cell body
Polar bonds are when negatives and positives are attracted to eachother
Answer:
We have just seen that pathogens constitute a diverse set of agents. There are correspondingly diverse ranges of mechanisms by which pathogens cause disease. But the survival and success of all pathogens require that they colonize the host, reach an appropriate niche, avoid host defenses, replicate, and exit the infected host to spread to an uninfected one. In this section, we examine the common strategies that are used by many pathogens to accomplish these tasks.
Explanation:
The first step in infection is for the pathogen to colonize the host. Most parts of the human body are well-protected from the environment by a thick and fairly tough covering of skin. The protective boundaries in some other human tissues (eyes, nasal passages and respiratory tract, mouth and digestive tract, urinary tract, and female genital tract) are less robust. For example, in the lungs and small intestine where oxygen and nutrients, respectively, are absorbed from the environment, the barrier is just a single monolayer of epithelial cells.
Skin and many other barrier epithelial surfaces are usually densely populated by normal flora. Some bacterial and fungal pathogens also colonize these surfaces and attempt to outcompete the normal flora, but most of them (as well as all viruses) avoid such competition by crossing these barriers to gain access to unoccupied niches within the host.
Answer:
True
Explanation:
Because within the prokaryotic domain, there are five main groups of bacteria that perform tetrapyrrole-based photosynthesis. They are proteobacteria (also known as purple bacteria), heliobacteria, Chloroflexi (filamentous bacteria also known as green non-sulfur bacteria), Chlorobi (green sulfur bacteria), and cyanobacteria.
