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.
Answer:
Atmosphere
Explanation:
Phosphorus cycle in nature is a unique cycle compared to the other natural biological and chemical cycles such as the carbon, nitrogen, sulfur and water cycles, as there is no gaseous phase in the phosphorous cycle. Due to the prevailing atmospheric temperature and pressure which are not appropriate for the formation of gases associated with phosphorus, the compounds in nature where phosphorus can be found are not gases. Phosphorus can therefore be found majorly in sedimentary rocks.
Answer:
<em>The correct option is C) C-shaped cartilage rings </em>
Explanation:
The trachea is commonly known as the wind-pipe. The trachea can be described as about a 4 inch long passage from which the air travels into the bronchi and lungs. The pathway of the trachea is kept open by C- shaped cartilages which are lined all over in the trachea. The C-shaped cartilages protects as well as maintain the shape of the wind-pipe. The rigidity of the trachea arises from the C-shaped cartilages.
