Which of the following attributes of life are only valid for multicellular organ
ID: 227414 • Letter: W
Question
Which of the following attributes of life are only valid for multicellular organisms and not for single celled organisms? (You will need to choose from the list] A cell can potentially modify its activities by undergoing any of the following biochemical changes EXCEPT? [You will need to choose from a list] One of the laws of thermodynamics states that all systems have an overall tendency towards disorder. The tendency for cells to grow and divide (and thus make a number of self-contained orderly systems) does not violate this law. Why? (You will need to choose from a list] Yore way was analyzing the chemical composition of cells he isolated from the mud in a pond and comparing it to the chemical composition of the mud itself. He noticed that the four most abundant elements in the cell were not the same as the four most abundant elements in the mud itself. Why? (You will need to choose from a list] Who first coined the use of the term "cells" to describe the biological compartments found in organisms? (You will need to choose from a list] The formation of a bond from a condensation reaction always generates a by-product molecule of what? [You will need to choose from a list] Lois Learn lot was reading up about nucleic acids and noticed that in books and articles that strands of nucleic acids have a denoted directionality, with one end designated 5' and the other end designated 3'. But she couldn't quite figure out what they stood for. Can you help her? a) Using the diagram below, determine which are structures on the nucleotide that the 5' and 3' stand for and b) state which reason best explains why these notations are used to discuss the directionality of a nucleic acid strand.Explanation / Answer
Answer: (The questions have been answered in general since no options/list were provided)
1. Multicellularity gives rise naturally to increasing levels of complexity, which leads to differentiation of cellular functions and the development of specialist cells and organs. Such specialist cells perform vital roles within the organism but are generally not able to survive outside it.
As the number of cells in an organism grows, so too does its size, and so in contrast to most single-celled organisms, multicellular life is frequently macroscopic (visible to the naked eye).
All multicellular organisms are eukaryotic, which means their cells contain membrane-bound structures.
All animals and plants, most fungi, and some algae are multicellular, though most of the Earth's biomass is comprised of single-celled organisms which are predominantly bacteria.
2. The environments in which cells grow often change rapidly. For example, cells may consume all of a particular food source and must utilize others. To survive in a changing world, cells evolved mechanisms for adjusting their biochemistry in response to signals indicating environmental change.
Initially, the detection of environmental signals occurred inside cells. Chemicals that could pass into cells, either by diffusion through the cell membrane or by the action of transport proteins, and could bind directly to proteins inside the cell and modulate their activities.
An example is the use of the sugar arabinose by the bacterium Escherichia coli. E. coli cells are normally unable to use arabinose efficiently as a source of energy. However, if arabinose is their only source of carbon, E. coli cells synthesize enzymes that catalyze the conversion of this sugar into useful forms.
3. Living cells, while not violating the entropy law, do overcome it for a while by feeding on free energy (energy available to do work) in food taken from the surroundings.Non-living systems cannot do this. The structures in living cells are held together only by fairly weak bonding forces. Therefore, they are easily broken down by the random heat motions of the molecules.
This is an entropy effect. In a dead cell this process soon reduces the cell to formless rubbish. In a living cell energy imported from outside powers a multitude of repair projects that operate continually. They are guided by the plans carried in the DNA molecules, the genes, so that the correct cell structure is preserved.
The DNA molecules are held together by stronger forces than is the general cell structure; therefore the plans are not normally altered by the molecular heat motions. Gradually, however, the degenerative entropy effect does cause the breakdown of some of the permanent structures of the cell, including probably alteration of the DNA, and this leads to aging and death. Non-living systems cannot duplicate the entropy-overcoming activities of living cells.
4. The most common elements on Earth are oxygen, silicone, aluminum and iron. Oxygen makes up about 46 percent of Earth by weight, while silicone makes up about 28 percent, and aluminum and iron make up approximately 8 and 5.5 percent, respectively.
Living organisms, however, are made of only a small selection of these elements, four of which carbon, hydrogen, nitrogen, and oxygen make up 96.5% of an organism's weight.
The most essential elements which make up the cellular constituents are the above 4 elements. Examples include: i. C, H, N and O which forms the backbone of amino acids (buliding blocks of protein)
ii. H and O make up water which constitutes 70% of the cell's weight.
Thus, the 4 most abundant elements in cells and mud are different.
(Answered the first 4 questions according to the rules of Chegg)
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