Answer:
All the above
Explanation:
A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports fluids between the roots and the shoots in the xylem and phloem, stores nutrients, and produces new living tissue.
Stems have four main functions which are:[1]
Support for and the elevation of leaves, flowers and fruits. The stems keep the leaves in the light and provide a place for the plant to keep its flowers and fruits.
Transport of fluids between the roots and the shoots in the xylem and phloem(see below)
Storage of nutrients
Production of new living tissue. The normal lifespan of plant cells is one to three years. Stems have cells called meristems that annually generate new living tissue.
Answer:
la selección natural es el mecanismo principal por el cual la evolución ocurre
Explanation:
Charles Darwin fue un naturalista inglés que propuso la teoría de la evolución o 'descendencia con modificación' mediante el mecanismo de selección natural. Acorde a esta teoría, la selección natural se define como el mecanismo selectivo de reproducción diferencial de los individuos mejor adaptados a su ambiente. La variabilidad es el la materia prima sobre la cual la selección natural actúa, seleccionado aquellos individuos que presentan combinaciones fenotípicas y genotípicas más adaptadas para sobrevivir en un ambiente en particular. Los individuos de una población que son 'superiores adaptativamente' poseen más chances de sobrevivir y reproducirse, y por lo tanto tienen también más probabilidades de transmitir sus genes a la siguiente generación.
Explanation:
Spillover infection, also known as pathogen spillover and spillover event, occurs when a reservoir population with a high pathogen prevalence comes into contact with a novel host population. The pathogen is transmitted from the reservoir population and may or may not be transmitted within the host population.
The sole reason why red blood cells are unable to replace damaged proteins is that red blood cells lack DNA and cell organelles such as nucleus, ribosomes and mitochondria which are crucial for protein synthesis, assembly and repair. In other words they lack both the information and the machinery for making or repair of proteins.
Due to lack of DNA and cell organelles, red blood cells cannot be able satisfy the central dogma which summarizes synthesis of proteins as DNA → RNA → proteins.
DNA has the genetic information on how proteins should be made, RNA is responsible for transferring the information from DNA in the cell nucleus to the ribosomes in the cytoplasm, then translating or decoding this information, which results in the making of protein.
Answer:
Abiotic components of an ecosystem are water, air, light, soil, and temperature.
Now think about how the availability of these things will affect what could live in a specific area.
Consider a desert ecosystem. Deserts are arid, receiving little rain (water) and have extreme temperatures (both cold and hot). Because of these conditions only certain plants and animals can live here. These plants and animals have adaptations that are specific to the environment. If you were to put an organism that does not belong in there, they would most likely die out.
Tidbit for you. The Atacama desert is one of the driest places in the world, located specifically in Chile. At one point, this place did not receive any rain for 500 years! Still plants and animals are able to live in this area. When it finally did rain, the sudden downpour caused a radical change in this ecosystem. You would think at first rain would be good, but no. Because the changes the rain brought was too drastic, it caused a devastating effect on the organisms that lived there because they were not adapted to rain.
