Answer: According to Darwin theory of evolution the struggle for existence is considered as major part for competition among living things.
Explanation:
Coexisting species that belong to the same genera compete for same kind of resources for their survival. Some phenotypic variations gives an survival advantage over others. The superior ones dominate the inferior ones and compete for resources. The one who receives the resources like mates, food, shelter, and others the chances of survival also increases considerably.
During exercise stroke volume increases because more blood is sent back to the heart due to the muscles squeezing blood in the veins
Trichonympha lives in the gut of termites and digests cellulose eaten by the termite.
Answer:
1.Plasma membrane
The plasma membrane surrounds the cell to create a barrier between the cytosol and the extracellular matrix. Plasma membranes also enclose lumens of some cellular organelles.
2.Endoplasmic reticulum
The endoplasmic reticulum (ER) is a large network of membranes responsible for the production of proteins, metabolism and transportation of lipids, and detoxification of poisons. There are two types of endoplasmic reticulum with separate functions: smooth endoplasmic reticulum and rough endoplasmic reticulum. The presence or absence of ribosomes in the ER’s plasma membrane determines whether it is classified as smooth or rough ER.
3.Golgi apparatus
The Golgi apparatus appears as a series of flattened, membranous sacs, or cisternae, that resemble a stack of pancakes just off the rough endoplasmic reticulum. It receives vesicles containing proteins recently produced by the rER. The Golgi apparatus can be compared to a warehouse or post office for newly formed proteins. Here the proteins are further modified, packaged, and sent off to their final destinations in the cell or body.
Coronary artery.....are the arteries that provide blood to the wall of heart !