Answer:
a) Natural selection may lead to the evolution of prezygotic reproductive isolation in organisms that already have postzygotic isolation to prevent wasted reproductive effort
Explanation:
Prezygotic reproductive isolation produces postzygotic reproductive isolation because this mechanism lead to genetic differences that impair the pairing of homologous chromosomes during meiosis.
The external cell membrane. Even organisms as simple as bacteria have a cell membrane.
Prokaryotes do not have internal membranes but they still have external membranes.
Everything living thing has a cell membrane
Answer:
1. At the end of S phase- 20 pg DNA
2. At the end of G2 phase- 20 Pg DNA
Explanation:
The cell before undergoing M phase undergoes the steps of interphase that is G₁, S and G₂ phase.
During S phase, the process of cell replication takes place which replicates the DNA as a result of which the amount of DNA doubles. This DNA amount is reduced to half during the anaphase stage of M phase.
In the question since the amount of DNA is 10pg therefore the amount will be double during S phase and becomes 20 pg and will remain 20 pg until the DNA is distributed therefore at the end of G₂ phase Will remain the 20 pg.