Answer:
The correct option is A
Explanation:
To determine if water temperature has an effect on weathering of sedimentary rocks, different number (perhaps three) of identical sedimentary rocks should be obtained and then individually placed in different water temperatures (with at least one of the "water volumes" used for each having a temperature close to the room temperature so as to be used as the control).
Thus, each of the identical sedimentary rock can be broken into three and placed individually; as in one part of the rock in 20 °C of water (control), another part of the rock in 40 °C and another in 60 °C of water.
This above procedure should be repeated for the remaining two other identical sedimentary rock to confirm if there is any effect.
The plant contains vascular tissue and has an alternation of generation. But, it lacks seeds. So, the plant is a Pteridophyte.
- Vascular tissues are absent in thallophytes and bryophytes. They are found in pteridophytes, gymnosperms and angiosperms.
- The sporophyte and gametophyte generation is common in bryophytes and pteridophytes.
- Seeds are produced in plants that come under the group gymnosperms and angiosperms. The presence of seeds is the main characteristic of these groups.
- Thallophytes, bryophytes and pteridophytes lack seeds. The reproduction in plants that comes under these groups occurs with the help of spores.
Thus, the recently discovered species of the plant should be classified based on the presence of vascular tissues, gametophytes and sporophytes. As pteridophytes contain vascular tissues, sporophytes and gametophytes and lack seeds, the plant is a pteridophyte
Learn more about pteridophytes here:
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In American Indian so they Thad the highest concentration toxins
Answer:
18:repeat the experiment again
Explanation:
Because repeating the experiment would get rid of inaccurate data