Pre AP Biology -ECO 1.1 Hydrologic Cycle- MCQ Exam Style Questions -New Syllabus
Pre AP Biology -ECO 1.1 Hydrologic Cycle- MCQ Exam Style Questions – New Syllabus
Pre AP Biology -ECO 1.1 Hydrologic Cycle- MCQ Exam Style Questions – Pre AP Biology – per latest Pre AP Biology Syllabus.
▶️ Answer/Explanation
The correct answer is a. a radicle.
During seed germination, the radicle is the first part of the embryo to emerge.
It grows downward into the soil to become the primary root of the plant.
The epicotyl eventually develops into the upper stem and leaves.
The hypocotyl is the transition zone between the radicle and the cotyledons.
The coleoptile is a protective sheath covering the emerging shoot in monocots.
Therefore, the root system originates specifically from the embryonic radicle.
▶️ Answer/Explanation
The correct option is b.
The IUCN has assessed only a small fraction of the estimated $8.7$ million eukaryotic species on Earth.
Monitoring efforts are heavily biased toward vertebrates and conspicuous plants, leaving many invertebrates and fungi unexamined.
Many “Data Deficient” species are likely at risk but cannot be formally listed as threatened without more evidence.
Cryptozoic or deep-sea species often face habitat loss before they are even discovered or assessed.
Therefore, the current count of threatened species is a significant underestimation of the true global total.
▶️ Answer/Explanation
The correct answer is b. $10\%$.
This concept is known as the Tens Rule in invasion biology.
It suggests that only $10\%$ of imported species actually escape into the wild.
Of those that escape, only $10\%$ (which is $1\%$ of the original) become established.
Furthermore, only $10\%$ of established species eventually become pests or invasive.
Most introduced species fail to survive due to lack of resources or unsuitable climate.
Therefore, the estimated establishment rate is approximately $10\%$.