<u>Answer</u>:
The high sea surface salinity can be observed in the Pacific Ocean, the Indian Ocean, the Arabic ocean and the Mediterranean sea.
<u>Explanation</u>:
Due to rainfall and evaporation of water from sea the density varies with varying salts and minerals concentration that aggregate at the surface. The salinity in the seawater varies according to the amount of evaporation from a particular area.
Low salinity water is found in polar and subpolar regions that are near to the equator. Regions of high salinity are observed in the seawater which is centered around 30 degrees north and 30 degrees south to the equator due to the excess evaporation in these areas.
The Central Nervous system is made out of spinal cords that connect to the brain.
Answer: The correct statements are 1 and 2:
1.Self-pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant.
2.Cross-pollination is the transfer of pollen from the anther of one flower to the stigma of another flower on a different individual of the same species.
Explanation:
Pollination is the transfer of pollen grains from an anthers to a receptive stigma. In most species of flowering plants, external agents bring about pollination. Also, flowers have evolved special structures and mechanisms to ensure successful pollination.
There are two types of pollination
--> Self pollination: This takes place when mature pollen grains from the anther of a flower fall on the stigma of the same flower or that of another flower on the same plant. This type of pollination brings the male gametes and egg cells of the same plant together. The resultant offspring show very little genetic variation.
--> Cross pollination: This occurs when mature pollen grains of a flower are transferred to the stigma of a flower of another plant of the same or closely related species. This brings the male gametes and egg cells of two different parent plants together. Therefore, there is greater genetic variation among the offspring.
