Answer:
Laws of stratigraphy help scientists determine the relative ages of rocks. This law states that deeper rock layers are older than layers closer to the surface. An unconformity is a gap in rock layers. They occur where older rock layers eroded completely before new rock layers were deposited.
Explanation:
The study of rock strata is called stratigraphy. The laws of stratigraphy can help scientists understand Earth’s past. The laws of stratigraphy are usually credited to a geologist from Denmark named Nicolas Steno. He lived in the 1600s.
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Brain-List?
Answer:
D.
Explanation:
The immune system lowers the chances of bacteria, viruses, and diseases entering your body
Answer:
M phase: 4.8 hr
Prophase: 2.4 hr
Prometaphase: 0.72 hr
Metaphase: 0.24 hr
Anaphase: 0.84 hr
Telophase: 0.6 hr
Explanation:
Mitosis, also known as M phase, is the process of nuclear division after interphase, which is followed by cytoplasmic division via cytokinesis. Mitosis can be subdivided into the following phases: Prophase, Prometaphase, Metaphase, Anaphase, and Telophase. In this case, 160 cells are in interphase (for a total of 200 cells), thereby 40 cells are in mitosis >> 200 - 160 = 40 cells. Since the complete cell cycle requires 24 hours, it is possible to calculate the average duration of each phase:
M phase: 40/200 = 0.2 x 24 hr = 4.8 hr
Prophase: 20/200 = 0.1 x 24 hr = 2.4 hr
Prometaphase: 6/200 = 0.030 x 24 hr = 0.72 hr
Metaphase: 2/200 = 0.01 x 24 hr = 0.24 hr
Anaphase: 7/200 = 0.035 x 24 hr = 0.84 hr
Telophase: 5/200 = 0.025 x 24 hr = 0.6 hr
Answer:
The correct answer is option B, that is, an endoskeleton evolved to enclose the dorsal nerve cord, which develops from the notochord.
Explanation:
It has been discovered that the ancestors of the modern-day fish were vertebrate chordates. The vertebrate chordates are considered to have evolved from the invertebrate chordates that are identical to the present day tunicates. It has been found that in vertebrates the endoskeleton has evolved to encompass the dorsal nerve cord that has been developed from the notochord (a characteristic of invertebrates).