Answer:
The correct answer would be D.Alveolar sacs are surrounded by thin capillaries where gases can be exchanged.
Alveoli are tiny sacs which form the site of gas exchange in the lungs.
The features of alveoli which help in gas exchange are:
- They increase the surface area in the lungs thus, more space is available for gas exchange.
- They have very thin walls, as thin as the thickness of a single cell only.
- They are surrounded by a bunch of thin capillaries which exchange gases with alveoli.
I think the 4 major types of vectors are plasmids, viral vectors, cosmids, and artificial chromosomes. The most commonly used vectors are plasmids.
Hope this helps! ;0
Answer:
1. Survivors of the pesticide have a gene that protects them from it.
2. Then the survivors pass on the gene to their offspring,
3. Each time the pesticide is sprayed, the insects have a greater chance of survival.
To smell and feel surfaces and sense temperatures
Mercury has the smallest orbit and neptune has the largest. so neptune would take a longer amount of time to orbit the sun.
