Shells are considered biotic because they come from living things. Biotic describes something living or use to be living such as plants and animals. So shells are considered biotic because they come from a living organism.
~~~~~~~~~~~~~~~~~~~
Hope that helped:)
~~~~~~~~~~~~~~~~~~~
Answer:
D
Explanation:
Alternative energy is best defined as the use of energy sources other than traditional fossil fuels, which are considered environmentally harmful and are in short supply. Fossil fuels consist of natural gas, coal, and oil. Currently, fossil fuels are the most used energy source to heat our homes and power our cars.
Microfilaments
Microfilaments are fine, thread-like protein fibers, 3-6 nm in diameter. They are composed predominantly of a contractile protein called actin, which is the most abundant cellular protein. Microfilaments' association with the protein myosin is responsible for muscle contraction. Microfilaments can also carry out cellular movements including gliding, contraction, and cytokinesis.
Microtubules
Microtubules are cylindrical tubes, 20-25 nm in diameter. They are composed of subunits of the protein tubulin--these subunits are termed alpha and beta. Microtubules act as a scaffold to determine cell shape, and provide a set of "tracks" for cell organelles and vesicles to move on. Microtubules also form the spindle fibers for separating chromosomes during mitosis. When arranged in geometric patterns inside flagella and cilia, they are used for locomotion.
Hope this helps :)
Answer: protists
Explanation:
Answer:
The correct option is B <em>Pressure-sensitive baroreceptors uses tonic receptors which adapt slowly to the stimulus</em>
Explanation:
a. The thalamus receives stimulus from all of the five senses (sight, smell, taste, hear, touch). FALSE. Olfactory information is not sent to the thalamus for its process. The rest is.
b. Pressure-sensitive baroreceptors uses tonic receptors which adapt slowly to the stimulus. TRUE. Among the different types of tonic receptors, we may find baroreceptors, irritation receptors, tactile receptors, and proprioceptors. Tonic receptors characterize by their slow adaptation to the stimulus. The first discharge is maximal when the stimulus is received and then it progressively decreases. They send a continuous signal to the CNS.
c. The three layers that the retina is made of: photoreceptors, bipolar cells, rod cells. FALSE. There are in fact three layers in the retina: photoreceptors, bipolar cells, and ganglion cell layers. NOT rod cells.
d. The sense of smell uses phasic receptors which continuously fire as long as the stimulus is present. FALSE. Olfactive sense uses phasic receptors, but not continuously. These receptors shoot when they receive the stimulus, and then cease if the stimulus keeps constant.
