Answer:
Bacterial DNA is contained in one circular chromosome, located in the cytoplasm. Eukaryotes have several linear chromosomes. Bacteria also have two additional unique features: a cell wall and flagella. Some bacteria also have a capsule outside the cell wall
Answer:
Mutations and sexual reproduction increase genetic variation in a population. Natural selection occurs when environmental pressures favor certain traits that are passed on to offspring. ... Individuals may mutate, but natural selection acts by shifting the characteristics of the population as a whole.
Explanation:
Answer:
the nutrients in the food is absorbed
The answer is; the melanin in darkly pigmented skin protects DNA from UV radiation, and UV radiation can cause skin cancer
In Africa, due to its equatorial latitude location, receives direct sunlight at more or less 90 degrees most of the year. These highly concentrated rays increase the UV radiation exposure that can cause damage to cell DNA. Selection pressure, therefore, favored individuals with high melanin concentrations that protect against UV. Therefore population evolved towards high melanin densities in the skin.
Answer:
If an inhibitory synapse fires at the same time and at the same distance from the initial segment as an excitatory synapse of the same intensity there will be no changes in the potential in the firing zone.
Explanation:
Under normal conditions, the transmembrane potential depends on the ionic charges present in the intracellular and extracellular spaces. The extracellular space load is usually positive and in the cytoplasm is negative.
- <u>Depolarization</u> occurs by opening ion channels that allow sodium to enter the cell, making the intracellular space more positive.
- An opening of potassium channels releases this ion to the extracellular space, leading to <u>hyperpolarization</u>.
An excitatory synapse is one capable of depolarizing a cell and boosting the production of action potential, provided it is capable of reaching the threshold of said potential.
On the other hand, an inhibitory synapse is able to hyperpolarize the cell membrane and prevent an action potential from originating, so that they can inhibit the action of an excitatory synapse.
The interaction between two synapses, one excitatory and one inhibitory, -called synapse summation- will depend on the strength that each of them possesses. In this case, the intensity of both synapses being the same, there will be no changes in the membrane potential in the firing zone.
Learn more:
Excitatory and inhibitory postsynaptic potentials brainly.com/question/3521553