Answer:
Reflex arcs
Sensory neuron sends electrical impulses to a relay neuron, which is located in the spinal cord of the CNS. Relay neurons connect sensory neurons to motor neurons. Motor neuron sends electrical impulses to an effector. Effector produces a response (muscle contracts to move hand away).
Answer : True
Enrichment cultures are used to increase a small number of desired organisms
Parietal and frontal.. whichever one your looking for
Answer:
The main difference between sieve tubes and companion cells is that sieve tubes are the long, narrow, pointed tubes present in the phloem of angiosperms whereas companion cells are attached to the sieve tubes, regulating the activity of sieve tubes.
This is true. There are a few websites online that talk about how it happens, I suggest looking them up.