<span>It
considered that all terrestrial plant species that exist today have evolved
from Rhyniophyta (a type of spore plants, compiled by the most primitive forms
of vascular). Now terrestrial plants presents by the Moss family, psilotaceae, lycopsids,
class of the Horsetail, fern, gymnosperms and flowering plants. Based on the cladogram, It assumed that the
ancestors of all existing plants are algae, particularly green.</span>
Answer:
2n to n, n to 2n
Explanation:
Meiosis is known as reductional division because in meiosis the chromosome number gets reduced to half in daughter cells so when sperm and egg cells undergo meiosis than the chromosome numbers get reduced from 2n to n. In humans, the chromosome number is 46 and it gets reduced to 23 after meiosis.
When egg is fertilized by the sperm than the two chromosomes comes in the same cell and the number goes from n to 2n that mean in human it goes from 23 to 46.
78.08% nitrogen
<span>20.95% oxygen </span>
<span>an average of 0.247% water vapour (very variable) </span>
<span>& approximately 1% of other gases </span>
<span>These other gases are the noble gases consisting of :- </span>
<span>Argon (0.93%) </span>
<span>Neon (less than 0.01%) </span>
<span>Helium (less than 0.01%) </span>
<span>Krypton (less than 0.01%) </span>
<span>Xenon (less than 0.01%) </span>
<span>Radon (less than 0.01%) </span>
C) Allow the heavily degraded ecosystems to disappear
