Answer:
The behavior of chromosomes during meiosis and fertilization is responsible for most of the variation that arises in each generation. Three mechanisms contribute to genetic variation arising from sexual reproduction: independent assortment of chromosomes, crossing over, and random fertilization.
Answer:
Renewable energy resource as an obstacles for the growth of migratory salmon populations: It is now believed that the reduce access to spawning grounds and nursery areas, leading to a decrease in migratory fish populations is due to the dam structures of large storage-type schemes, which can create great obstacles for the movement of migratory fish species.
Explanation:
- Storage-type schemes ( big dams) can significantly change the downstream flow regime,and may also alter water temperature and quality, and even make it inhabitable for fish to live.
- As the storage of water can be linked with high evaporative losses, which in turn results in high life cycle water footprints compared to other sources of electricity.
<u>Run-of-river (ROR) schemes are HEP schemes: </u>
They operate without water storage, using the flow within a river channel.They are ecologically friendly and do not disturb the natural mechanism for the migrating salmons.
Working Principle:
They are normally used to regulate water levels, which allows a proportion or part of flow to be diverted down a secondary channel to a turbine before it is returned to the main channel further downstream.
There are some modern turbine types used in ROR HEP(hydroelectric power) schemes, which are also designed to allow fish to pass through the system unharmed if the fish do pass through the intake screens.
The right answer is <span>Refractory period.
At the moment when the action potential is emitted, the fiber being depolarized, it is impossible to depolarize it again. It is, therefore, necessary to wait until the membrane potential returns to a value below the critical threshold in order to be able to excite it again. We are thus led to distinguish two periods that characterize its excitability.
An absolute refractory period: during which any stimulation, even supraliminal, is ineffective since the fiber is already depolarized.
A relative refractory period: during which a second action potential can be omitted provided that the depolarization produced by the excitation reaches the critical threshold, which implies that it is more important since the value of the resting potential has not been restored yet.</span>
Answer:
It would affect the functionality of the other levels including the organism
Explanation:
The level of biological organization is a hierarchical step consisting of how a multicellular organism forms. According to this level of organization, CELLS are the simplest unit of life and the collection of cells with a similar function is termed TISSUE. Tissues form ORGANS, organs form ORGAN SYSTEMS and finally, a collection of all the systems in the body forms the ORGANISM.
Based on this, one would observe that each level is related to the next in such a way that one forms from the other. Hence, if one of the levels in the biological organization will not perform its function properly, the other levels will be affected. For example, if the kidney cells do not perform it's function, it would affect the functionality of the kidney tissues, kidney organ, the excretory system, and the organism at large.
Both complete and incomplete metamorphosis extend from the egg stage to the adult stage. Complete metamorphosis consists of four stages: egg, larva, pupa, and adult. However, the incomplete metamorphosis consists of three stages: egg, nymph, and adult.
Hope This Helps.
