Answer: Natural variation.
The third one.……...................
Answer:
Random mutations led to evolution of pesticide resistance genes in bed bugs.
Explanation:
Random mutations in genome of bed bug imparted them the pesticide resistance. Since the bed bugs having the mutation of pesticide resistance were able to survive under presence of pesticides, this variation was favored by natural selection. The bugs with pesticide resistance transmitted this trait to their progeny. In time, the bed bug population consisted of most of the bugs having the pesticide resistance.
Option D is correct.
A synapse is the opening between neurons that neurotransmitters pass through.
Answer:
c. They lack lignified vascular tissue
Explanation:
We know that forest consists of tall trees. In the tall trees the water and minerals are transported to the every part of tree through the lignified vasucular tissue. This tissue not only helps in transport within the tree but also provides some sort of mechanical strength due to the presence of lignin it its walls. On the other hand bryophytes are non-vascular plants which means they lack vascular tissue and thus a mechanism for long distnace transport of water and minerals is absent in them. So they can't be taller as a tree and thus can't form forest.
