Answer:
2. Tuber
Explanation:
Reproduction is the process by which living organisms multiply themselves. They do this through two major ways namely: asexually and sexually. Sexual reproduction involves two organisms (male and female) that each donate a gamete (sperm and egg). In plants, the sexual reproductive structure is the FLOWER. The male flower is called STAMEN, while the female flower is called PISTIL.
However, plants can also be propagated asexually by making use of certain plant parts including tubers, leaf etc. TUBER is a structure in plant specifically used to asexually reproduce plants like yam, potato, cassava etc.
Nitrogen fixation is a process in which nitrogen (N2) in the Earth's atmosphere is converted into ammonia (NH3). Atmospheric nitrogen or molecular dinitrogen (N2) is relatively inert: it does not easily react with other chemicals to form new compounds.
Answer:
It is a season in which fish reproduce.
Explanation:
Piracema is not name of the fish, its the name given to the period of the year when fish reproduce within the Paraguay River. The season of reproduction started from October till March, during this period the fish swim upstream to lay their eggs and reproduce. Thus the season is critical for the maintenance of fish populations in the waters of the rivers and lakes. Brazilian states prohibit fishing during this period in order to maintain fish population in the river.
Mario sets up an experiment to determine the source of the oxygen gas produced by photosynthesis. To determine this, he uses an isotope of oxygen called O-18. He labels the O-18 oxygen so he can follow its path through photosynthesis. Plant A is given carbon dioxide that contains the O-18 isotope. Plant B is given water that contains the O-18 isotope. When he examines the oxygen from both plants, only plant B produced O-18 oxygen. This indicates that the source of oxygen is water. The photosynthesis involves the transfer of electrons between the photosystem I and II. The water gets split into oxygen, hydrogen ions and electrons in the photosystem I. The electrons move to the photosystem II where the carbon fixation into sugars takes place. The plant A will have O-18 isotope in its synthesised sugar molecule, which gets stored inside it.
