1) Arithmetic density- the number of people per square unit of land
2) Physiologic density- Is the number of people per square unit of farmland.
3) Agricultural density- is the number farmers per unit of farmland.
Bryophytes are known as non-vascular plants - what makes them non-vascular is the a<span>bsence of xylem and phloem.</span>
The answer is A) they provide a source of energy.
The answer is moss.
Mosses are nonvascular seedless plants. <span>Nonvascular plants have simple tissues specialized for internal water transport.</span>
On the other side, vascular plants have vascular tissue which consists of xylem and phloem. Xylem transport water and minerals from the root to the upper parts of the plant. Phloem transports food and nutrients from the leaves, where they are produced, to the growing or storage parts of the plants.
Answer:
At 0 years, an event took place which is known as metamorphosis of igneous rock i.e., formation of igneous rocks from melted magma.
Strontium-90 is a radioactive element which undergoes beta decay to form yttrium-90. It has a half life of approximately 28 years and decay energy of 0.546 MeV. This radioactivity is used by geologist to estimate the age of the rock, fossils, meteorites etc. Other radioactive elements used by the geologists are carbon-40, potassium-40 etc.
Radiometric clock is set when the rock was formed in the past i.e., the moment when an ingenious rock was solidified from molten magma.