Answer:
Caroline Herschel
Explanation:
She was the first women to discover a comet and calculate its path.
Answer:
fossil fuel doesnt need atmospheric carbon for burning
Answer:
The correct answer would be zygote...blastocyst...embryo...fetus.
The fertilization of sperm and egg results in the formation of zygote. It receives genetic material from a male as well as a female parent.
It divides with the help of mitotic divisions and results in the formation of 2, 4, 8, and 16 celled stages.
It results in the formation of the hollow spherical ball of cells termed as a blastocyst. The cells are distributed to form the outer layer termed trophoblast and inner cell mass which gives rise to the embryo.
Trophoblast help in the implantation of the blastocyst into the uterine wall.
The cells of the embryo undergo organogenesis during different organs such as heart, brain, lungs et cetera are formed.
In humans, almost 9 weeks after the fertilization the developing embryo is considered a fetus.
The fetus development continues until birth.
Answer:
Explanation:
The four elements been referred to here are hydrogen, oxygen, carbon and nitrogen.
These four elements constitute the majority of the human body because of a combination of factors. Although, some of these factors are the major reasons, for instance the human body is made up of cells which are the basic structures of life. The cell consists of over 70% of water (which is made of hydrogen and oxygen). Also, oxygen is inhaled through the process of respiration which combines with other molecules (such as haemoglobin to form oxyhaemoglobin) in the human body. These among others make oxygen the most abundant element in the human body.
Naturally occurring organisms usually have a high concentration of organic molecules (molecules made of majorly carbon and hydrogen). This makes the human body have a high percentage (after oxygen) of carbon and hydrogen. Also, carbohydrates (which are later converted to glucose) form a large part of our diet and are stored in the body as glycogen (causing the body to have a high amount of carbon and hydrogen atoms).
Nitrogen is an essential part/element found in amino acids which are building blocks of protein. Proteins are involved in several metabolic activities in the body; this makes the abundance of nitrogen the fourth (one of the four) most common element in the body. It should be noted that amino acids also have carbon and hydrogen elements also.
The combination of the factors above among some other factors make the human body comprise mainly of these four elements
