Answer:
To maintain the right body temperature, it is essential to have adequate body fat. Body fats are the storehouses of energy in the body. Body fats are necessary to ensure the smooth functioning of cells. Body fats have a cushioning effect on organs and tissues.
Answer:
Firstly, the partial pressure of nitrogen (78%) is crucial to breathing purposes. Without this pressure, the lungs will burst and animals cannot survive.
Secondly, nitrogen is required for the formation of amino acids (building blocks of proteins) and other organic compounds that are necessary for the survival of living organisms. Principally, in the atmosphere, nitrogen is present in the form of molecular nitrogen (N2). N2 is fixed by nitrogen-fixing bacteria that form nitrates and nitrites. These molecules are then used in biochemical processes to produce proteins (amino acids) and other organic compounds. In the absence of nitrogen, these processes could become seize of limited significantly thus affecting life overall.
Thirdly, nitrogen and its derivatives act as greenhouse gases that maintain the Earth's temperature within a range that supports life. Yes, the increased abundance of nitrous oxides is not good because of acid rain and other issues, however, still, the presence of nitrogen is important for life on this planet.
The Gymnosperms and Angiosperms are groups of plants with seed, which means that they don’ t necessary acquire water for fertilization. These groups have made adaptations for sexual reproduction on dry land.
1) Gymnosperms (plants with the seeds are not enclosed in an ovary) have developed over the course of its evolution, structures that solved the main limitations present in the Pteridophytes in relation to sexual reproduction, in the terrestrial environment. The main changes that happened as an evolutionary adaptation to dry land are those on the seeds and pollen. The advantages of the seeds are: the storage tissue which sustains growth and a protective coat of the seeds. Seed is enveloped with the layers of hardened tissue which prevents desiccation. This is what frees reproduction from the need for a constant supply of water. <span>The sperm (male gamete) of gymnosperms</span> is enclosed in a pollen grain. Thi structure is protected from desiccation and can reach the female organs without dependence on water. Gymnosperms also developed structures called cupules to enclose and protect the ovule (the female gametophyte) which will develop into a seed upon fertilization.
2) Angiosperms are a group of plants which protect their seeds within an ovary called a fruit. Angiosperms have special evolutionary adaptations. For example, they produce their gametes in separate organs, usually in a flower, so the fertilization and embryo development takes place inside an anatomical structure. That provides a stable system of sexual reproduction largely sheltered from environmental fluctuations like water need.
Answer:
La razón por la que a partir de los núcleos de las células del intestino de un renacuajo albino, se obtuvieron ranas albinas en lugar de células intenstinales, es que fué un experimento de clonación.
Explanation:
Este experimento realizado por John Gurdon en 1960, se conoce también como transferencia nuclear, y demostró que la información hereditaria guardada en el núcleo celular, es suficiente para generar un nuevo organismo y permanece integra durante el desarrollo de células diferenciadas debido a sus señales citoplásmicas.
