This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1922 Excerpt: ...in snapdragons and by Lindstrom in maize. In these instances the lethal factor is a lack of chlorophyll which is not fatal if inherited from a single parent because the deficiency is supplied by a gene for chlorophyll from the other parent, but when the lack comes from both parents it produces a seedling unable to ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1922 Excerpt: ...in snapdragons and by Lindstrom in maize. In these instances the lethal factor is a lack of chlorophyll which is not fatal if inherited from a single parent because the deficiency is supplied by a gene for chlorophyll from the other parent, but when the lack comes from both parents it produces a seedling unable to survive. Recently'G. H. Shull has demonstrated the existence of two balanced recessive lethal factors in one pair of the fourteen chromosomes in Oenothera, one pair producing a lethal effect in the zygote, the other pair destroying the gametes. This fact explains many of the hitherto confusing ratios obtained in breeding this classical plant. "Such lethal factors modify the expected Mendelian ratios and greatly complicate the study of genetics, but they do not destroy its fundamental principles, indeed when properly understood they furnish one of the strongest proofs of the truth of the factorial theory of heredity" (Conklin). 6. Modifying Genes And Selection The recognition of modifying genes has furnished an explanation for the apparent effectiveness of selection within a pure line without assuming germinal inconstancy. The gene itself, like that producing the hooded pattern of Castle's rats, is constant but it is accompanied by a halo of modifying genes likewise constant which have no somatic expression except when the original factor for hooded pattern is present. These modifying genes are simply potential increasers or diminishers of the hooded-pattern gene. In the absence of the pattern gene there is nothing to increase or diminish and consequently there is no way to demonstrate the modifying factors. They are not imaginary things, however, for their separate existence and transmissibility have been demonstrated from many sides. Wh...
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Add this copy of Genetics an Introduction to the Study of Heredity to cart. $9.68, fair condition, Sold by ThriftBooks-Dallas rated 5.0 out of 5 stars, ships from Dallas, TX, UNITED STATES, published by Macmillan.
Add this copy of Genetics: an Introduction to the Study of Heredity to cart. $19.27, poor condition, Sold by Anybook rated 5.0 out of 5 stars, ships from Lincoln, UNITED KINGDOM, published 1914 by The Macmillan Co.
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Seller's Description:
This book has hardback covers. Ex-library, With usual stamps and markings, In poor condition, suitable as a reading copy. No dust jacket. Please note the Image in this listing is a stock photo and may not match the covers of the actual item, 650grams, ISBN:
Add this copy of Genetics; an Introduction to the Study of Heredity to cart. $20.57, new condition, Sold by Ingram Customer Returns Center rated 5.0 out of 5 stars, ships from NV, USA, published 2022 by Legare Street Press.
Add this copy of Genetics, an Introduction to the Study of Heredity to cart. $21.00, very good condition, Sold by Common Crow Books rated 5.0 out of 5 stars, ships from Pittsburgh, PA, UNITED STATES, published 1913 by Macmillan.
Add this copy of Genetics: an Introduction to the Study of Heredity to cart. $23.64, good condition, Sold by Anybook rated 5.0 out of 5 stars, ships from Lincoln, UNITED KINGDOM, published 1920 by The Macmillan Co.
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Seller's Description:
This is an ex-library book and may have the usual library/used-book markings inside. This book has hardback covers. In good all round condition. No dust jacket. Please note the Image in this listing is a stock photo and may not match the covers of the actual item, 600grams, ISBN:
Add this copy of Genetics: An Introduction To The Study Of Heredity to cart. $29.16, new condition, Sold by Ingram Customer Returns Center rated 5.0 out of 5 stars, ships from NV, USA, published 2014 by Literary Licensing, LLC.
Add this copy of Genetics; an Introduction to the Study of Heredity to cart. $30.01, new condition, Sold by Ingram Customer Returns Center rated 5.0 out of 5 stars, ships from NV, USA, published 2022 by Legare Street Press.
