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.
There are bacteria, like the Pseudomonas fluorescens and Marimonas protea, that can reside even in frozen surfaces. They do it by entering a dormant state where they wait patiently to be free from ice and grow again.
Bacterial adaptation to cold surroundings also involves changes in their membrane composition and translation and transcription machinery. This includes bacterial conjugation.
The answer is A.
When organisms mate without human interference, it is called natural selection.
The process by which plants capture energy from the sun and store it in the chemical bonds of sugars and other food molecules they make.
