Duchenne muyscular dystrophy is caused by a mutation on the X chromosome, so a male gets it from his mother's X, if she is a carrier. The male child gets a Y and no X from his father, so the disease is always transmitted through the X from the mother. If a female gets Duchenne muscular dystrophy she has to have two X chromosomes, one from a carrier mother and another from from an affected father. This is virtually impossible because most males die before childbearing age and there is no way a female child can get an X from a man who does not live long enough to procreate. About eight percent of carrier women do show some muscle weakness, but they do not have the disease.
Answer:
Vacuole. A vacuole is a membrane-bound cell organelle. In animal cells, vacuoles are generally small and help sequester waste products. In plant cells, vacuoles help maintain water balance.
Explanation:
A) germination, there is no plant embryo before pollination
Answer:
The correct answer is - as energy lost at every trophic level.
Explanation:
In any ecological ecosystem the energy pyramids always upright unlike other pyramids such as biomass showing the number of organisms, that can be diamond shape, inverted or upright.
The main reason behind this is due to the fact that it is only a pyramid in the ecosystem that always unidirectional in the food chain which is always some energy lost with an increase in the trophic level in the food chain. This loss of energy always gets back to the atmosphere in each step of the food chain.
