If it has valves then it is a vein.
Answer: heres the 3 main functions.
Explanation:
membranes have three primary functions 1) they keep toxic substances out of the cell 2) they contain receptors and channels that allow specific molecules, such as ions, nutrients, wastes, and metabolic products, that mediate cellular and extracellular activities to pass between organelles and between the cell and the outside environment and 3) they separate vital but incompatible metabolic processes conducted within organelles.
Answer:
Burning of woods has a negative impact on the climate.
Explanation:
Burning of woods for heating has a negative impact on our climate because it releases carbondioxide gas which is a greenhouse gas that trapped the reflected solar radiation and leads to global warming. We have to used alternative methods for heating such as electric heater instead of burning of wood which produce no pollution and can fulfill the requirement of heating so from the above discussion we can say that the activity has a negative impact on the environment.
There can be a lot of factors that express sexuality. The origin would be its genes. The genetic make-up of the person what trait has passed on to an individual from his parents. Another factor is the environment. A person's sexuality can be influenced by social groups, home environment and from the media that he/she looks at.
In fact, the concordance rate of autism spectrum disorder was twice in identical twins that of non-twin siblings.
It has been shown that genetic has a huge influence on the development of autism spectrum disorder and that autism in identical twins was 13 times that of the general population. This suggest that environmental factors in the womb are the major factors that contribute.