I think the correct answer would be A. The yolk sac becomes the placenta. It is membranous sac that is attached to the embryo. It provides all the nutrition and the blood cells needed by the embryo. It is also called the umbilical vesicle.
D) A & B
it protects the seed against any damage or harmful weather conditions and also helps in dispersal of the seed through different means.
The one with higher air pressure is Warm Air. The reason why is because when you boil water, the water always makes the lid rise. This is because Warm Air has more activity in its atoms and molecules, so it is moving around more, which in turn means that there is more pressure.
Hope I helped. :)
Moths go under complete metamorphosis. So it's B. hope I helped!
Answer= Because polar bears depend on ice as a habitat to survive the more the temperature is rising and the sea ice melting as a result of global warming there is basically a possibility that the population of polar bears will decline because there will be no home (habitat)left for them to breed(survive)in.
