Fill in the gaps with the following words. selection / adaptation / application / remains / mature / transpiration / adjusts / predictselection / adaptation / application / remains / mature / transpiration / adjusts / predict
1. The loss of water from the leaf surface, called ______________, literally pulls water up the stem from the roots which have a greater water potential. 2. Darwin was the first to propose natural ______________ as an explanation for the mechanism of evolution that produced the diversity of life on earth. 3. The more complex the ______________ of an individual organism, the less likely that recombination will improve it, and the more likely that recombination will disrupt it. 4. Focusing is accomplished by contraction and relaxation of the ciliary muscle, which ______________ the curvature of the lens. 5. The origin of bipedalism, the key event in the evolution of hominids, ______________ a mystery. 6. The first and perhaps most obvious commercial ______________ of genetic engineering was the introduction of genes that encode clinically important proteins into bacteria. 7. Pleiotropic effects are difficult to ______________, because the genes that affect a trait often perform other functions we may know nothing about. 8. Courtship songs are sung by ______________ males and are species-specific.
Translate into Russian 1. Thus electron transport is thought to occur not by molecular collision between the components of the chain, but by means of an actual flow of electrons. 2. At least two distinct RNA fractions have been isolated from the cytoplasm, and one of them has been shown to vary greatly in amount from tissue to tissue. 3. Some variations in phenotype are shown to be caused by rearrangements or loss of large segments of the genetic material. 4. When the mutation rate is measured after different periods of growth of bacteria under identical conditions, it is always found to be the same. 5. The assumption is that the mutational events are distributed at random and this has been amply demonstrated to be the case. 6. When two pairs of alleles show less than 50 per cent recombination they are said to be linked. 7. A confirmation of the genetic heterogeneity of the gametes of heterozygote is found in the results of a cross of a heterozygote with a homozygote; there should be only two diploid combinations in equal proportions and this is found to be the case. 8. Many recessive alleles seem to exert no influence upon the phenotype, but only a comparison between recessivity and deficiency can provide critical evidence on this point. 9. The frequency of recombination between closely linked markers is often found to be lower than expected on the basis of linkage with more distant markers. 10. The segregation and recombination of genes were found to be governed by the mechanics of chromosome behaviour: whether normal or aberrant. The recombination of linked genes, attributed to the process of crossing-over, was shown to exhibit certain regularities. 11. It is most interesting that the bulk of this phage DNA seems to pass intact from generation to generation. 12. These and other temperate phage genes may be mapped and are found to exist in a linear order. 13. Bacterial cells can be shown to possess microscopically visible nuclei, but these have not been shown to divide by mitosis. 14. In bacteria, the DNA seems to exist in a relatively free form both in uninfected and in phage-infected bacteria. In viruses, too, the nucleic acids seem to be free of specific attachment to the protein coats which surround them. 15. When the observed frequency is found to be significantly less than 50 per cent, the genes are linked and can be assumed to lie on the same chromosome. 16. It is obvious that the evolution of HbS is likely to have been a single mutant event from HbA, for only a slight alteration of the base sequence is needed to change one amino acid in the B-chain. 17. The tertiary structure of the molecule with abnormal bridges is found to be less stable than the native form. 18. The plasma membrane about 75 Å thick appears to be composed of three separate layers. 19. These two bodies, lying at the right angles to each other near the nucleus, appear to be involved in the organization of the spindle during nuclear division. 20. The ribosomes appear to be recipients of specific «messages» from the genes of the nucleus. 21. Although living matter often contains traces of all the elements found in its surroundings, only some 20 elements have been demonstrated to be essential for life. 22. This specificity of proteins is believed not only to permit the regulation of the multitude of cellular processes, but also to be the molecular basis of the differences that exist between individuals and between species. 23. By 1956 some 75 enzymes had been crystallized and a great many more had been purified, and all of them were found to contain protein. 24. Radioactive traces indicate that all these pathways seem to be operating in the cell at the same time, though the traffic on the road leading to ribose via uronic acids seems to be insignificant compared to the other two. 25. There seems to be more species variation in the DNA ratios than in the RNA ratios, but since these values are averages of large numbers of different molecules more than one interpretation is possible.
UNIT 6 Nature and Subject of Biophysics The subjects of biophysics are the physical principles underlying all processes of living systems. This also includes the explanation of interactions of various physical influences on physiological functions, which is a special sub-area, called environmental biophysics. Biophysics is an interdisciplinary science somewhere between biology and physics, as may be concluded from its name, and is furthermore connected with other disciplines, such as mathematics, physical chemistry, and biochemistry. The term "biophysics" was first used in 1892 by Karl Pearson in his book The Grammar of Science. Does biophysics belong to biology, or is it a part of physics? Biology, by definition, claims to be a comprehensive science relating to all functions of living systems. Hence, biophysics, like genetics, biochemistry, physiology etc., should be considered as a specialized sub-area of biology. This view has not remained undisputed by physicists, since physics is not confined to subjects of inanimate matter. Biophysics can be considered, with equal justification, as a specialized part of physics. It would be futile to try to balance those aspects against each other. Both of them are justified. Biophysics cannot flourish unless cooperation is ensured between professionals from either side. Delimitation of biophysics from clearly unrelated areas has appeared to be much easier than its definition. Biophysics, for example, is by no means some sort of a melting pot for various physical methods and their applications to biological problems. The use of a magnifying glass, the most primitive optico-physical instrument, for example, has just as little to do with biophysics as the use of most up-to-date optical or electronic measuring instruments. Biophysical research, of course, requires modern methods, just as other fields of science do. The nature of biophysics, however, is actually defined by the scientific problems and approaches rather than by the applied methods. Biophysical chemistry and bioelectrochemistry can be considered as specialized sub-areas of biophysics. Medical physics, on the other hand, is an interdisciplinary area which has its roots in biophysics but has ramifications of far-reaching dimensions, even with medical engineering.
Define the following words using a dictionary Comprehensive, futile, ramification, delimitation, inanimate, underlying, to ensure, bioelectrochemistry
Complete the sentences
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