Answer:
Four daughter cells are produced each with 40 chromosomes. The daughter cells would exhibit genetic variations and would not be genetically identical to each other.
Explanation:
Meiosis is a cell division that forms four daughter cells from one parent cell as two sequential division meiosis I and meiosis II do not include any DNA replication between them. Crossing over during prophase-I of meiosis-I includes the exchange of genetic segments and occurs between the homologous chromosomes. It produces new gene combinations in the daughter cells which were otherwise not present in the parent cell.
Since there is no DNA replication between meiosis I and meiosis II, the daughter cells have half the number of the chromosomes compared to the parent cell. This occurs as homologous chromosomes move towards the opposite pole during anaphase I.
Therefore, a parent cell with 80 chromosomes will make a total of 4 daughter cells by meiosis. Each daughter cell would have 40 chromosomes. These daughter cells would have some new gene combinations and would be genetically dissimilar among themselves.
Answer:
limiting factors
Explanation:
The ecological optimum represents the value of the factors within the ecological valence at which the life processes of a species take place best. The upper and lower limits of an ecological valence are its maximum and minimum. Beyond these limits, physiological processes are interrupted and death occurs.
In mid-ocean ridge areas, ocean water is cycled through the crust because of the high heat flow in the area. Water in the rock is heated over the magmas, rising up and drawing in cold water from the sides. This process is occurring all over the world, and is the primary means for maintaining ocean salinity in a relatively constant range over the long term, as elements in the sea water when it is heated react with the rocks. There is so much water flow, cumulatively over the entire world, that this process basically buffers ocean chemistry.
Obviously large increases or decreases in salinity can and do occur in isolated basins that do not have free exchange with the open oceans.
The nucleus controls everything in a cell
