Out of the following given choices;
a. they increase the amount of energy transferred from the
lungs to the blood
b. they increase the flexibility of the lungs as they expand
during inhalation
c. they increase the volume of the lungs, allowing more
oxygen to be inhaled
d. they increase the surface area of the lungs, allowing the
efficient gas exchange
The answer is D. Due to their microscopic nature, they are numerous in the lungs and are also circular-shaped so as to increase the surface area for gaseous exchange.
Other characteristics of alveoli that increase gas exchange are that they thinned-walled (with only a layer of cells) and moist.
Answer:
5= mRNA is “messenger” RNA. mRNA is synthesized in the nucleus using the nucleotide sequence of DNA as a template. This process requires nucleotide triphosphates as substrates and is catalyzed by the enzyme RNA polymerase II. The process of making mRNA from DNA is called transcription, and it occurs in the nucleus.
Answer:
a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape,2 (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.
Carrying capacity of an ecosystem is the defined as the largest population that it can sustain indefinitely with the available resources. Biologists also refer to carrying capacity as the “maximum load”. Carrying capacity has factors it depends on. These are the many abiotic and biotic factors in the ecosystem and some are more obvious than others. The most obvious being, the availability of the basic needs of organisms which make up the different ecosystems. Some of these are food, water and shelter in which dictate how many individuals the ecosystem can sustain.
Answer:
Bacteria
Explanation:
Bacteria are a group of single celled organisms that are neither plants or animals.
Bacteria lack cell organelles such as the nucleus and the chlorophyll.
They can be found in many environments and most of them are adapted to survive in extreme environments such as hot-springs where the temperatures are extremely high.
Unlike the plant cell wall, bacterial cell wall has a layer of peptidoglucan which determines their shape. Their cytoplasm contains both DNA and RNA.
