Answer:
Is ther supposed to be a list or a picture ?
Explanation:
The ocean and the present atmosphere themselves are not leftovers from the original atmosphere of Earth. However, they do contain components within them that give us and scientists ideas of what Earth's past atmosphere was like.
Some example include:
1) Ice cores - scientists may go to Antartica or Alaska and stick this metal tube into the ice to remove what is known as an "ice core". This is then taken back to the lab for analysis. So what happens is that this ice as we know is constantly melting and freezing with different seasons and climate change. So, when the ice starts to crystallize, particles like carbon dioxide, sulfur etc may get trapped as bubbles in the ice. This is what scientists look for in ice coring and this is how they know that Carbon dioxide levels were relatively high back then (Not as high compared to now).
2) Ocean sediment cores - this is the exact same process of the ice cores except they take cores of sediments (esspecially calcium carbonate that contains oxygen). As you know, CaCO3 is found in the exoskeletons of organisms that die and build up on the ocean floor.
Those are some of the main ways that the present atmosphere and oceans have leftovers from the original atmosphere of Earth.
Hope that helped!
Answer:
The correct answer will be- zygote →cleavage→ morula→ blastula→ gastrula.
Explanation:
Human embryogenesis is the study of the formation of an embryo from the zygote formed after the fertilization of the sperm and egg cell.
The fertilization takes place in the ovarian duct in females which form a diploid zygote. The zygote starts the process of cleavage that is cell division and differentiation and leads to the formation of a 2 celled stage, 4 celled stages and later 16 celled stage. The 16 celled stage is known as morula which further undergoes cleavage and form blastula. The blastula now forms a gastrula with 3 layered distinction- the ectoderm, endoderm and mesoderm through gastrulation.
Thus, zygote →cleavage→ morula→ blastula→ gastrula is the correct answer.
Answer:
The major function of the immune system is to protect the host from environmental agents such as microbes or chemicals, thereby preserving the integrity of the body.
Explanation:
