Answer:
B. stomata.
Explanation:
Stomata are openings in the surface of the plant epidermis through which gases and water vapor pass. They are formed by two elongated cells whose shape is similar to bean grain or dumbbell depending on the species. These cells are called guard cells, and in their midst there is a slit called the ostiole.
The stomata make the exchanges between the external and internal environment of the plant. They regulate the size of the opening, so it is possible to increase or decrease the rate of perspiration of the plant.
Stomata are usually located at the bottom of the leaf, but in aquatic plants such as the water lily they are at the top and still in vertical growing plants on both sides.
Yes, it is. Potassium’s symbol is K. It’s atomic number 19.
Answer:
The animals present body structure is due to evolution. It is seen in each part including the structure of the heart. The vertebrate heart becomes complex from a simpler form.
Invertebrates, the heart of fishes is two-chambered having one auricle and one ventricle. The deoxygenated blood gets purified in the gills. They are aquatic and no lungs for breathing. The hearts pump a mixture of oxygenated and deoxygenated blood to the body.
The amphibians and reptiles have 3 chambered heart as they lead terrestrial mode of life. The gills modified into the lungs. The left auricle receives pure blood and the right auricle receives deoxygenated blood. The blood purified in the lungs and in the ventricle, both types of blood get a mix. The ventricle pumps the mixed-blood throughout the body.
In the case of birds and mammal, the heart is 4 chambered and the oxygenated and deoxygenated blood are separated. These two are higher vertebrates. No mix of pure and impure blood, the body receives only the oxygenated blood.
This shows to construct the phylogenetic tree of vertebrates - the fishes should be in the bottom, and above it amphibians, reptiles, then, mammals and birds on the top branch of the tree. As the chambers and structure of the hearts modified one after another.
The purpose of studying and dissecting an earthworm is to help us understand other organisms. Earthworms are organisms that are tube-shaped, segmented worms that belong to the phylum Annelida and in the species Lubricous. Earthworms decompose organic matter, break it into usable nutrients for their local ecosystems and recycle compost.
