11.3 Exploring Mendelian Genetics
重温先父遗传：后代继承他们母亲前配偶的获得性特征
用了几天时间，终于将一篇2014年发表于高阶学术期刊《生态学通讯》上的一篇关于先父遗传的论文翻译出来了。
这篇论文用实验证实了先父遗传的存在。
因为我认识的人中有学水产养殖的，所以很久之前我就听说过先父遗传现象，据说这种现象在养殖中是非常普遍的。
但后来我看到的所有资料都痛批它是伪科学，而以前我是深信“主流科学”意见的，所以一直没关注它。
后来我发现并解释了淫乱降低后代智力的规律，并一直坚持反淫乱宣传，但那时我觉得，以性解放分子宣传的歪理，中毒的人连自己的孩子是隔壁老王还是经纪人老宋的都不在乎，哪还在乎自己的孩子带有老婆的前炮友的相貌特征？所以先父遗传即使被证实是真的，对反淫乱宣传都没什么卵用。
前几天有个网友在天涯这发出消息，说有科学团队用实验证实先父遗传，出于好奇，我立即去下载了这篇论文来看。
一看之下很受启发。
至少这篇论文证明了，亲代的生活习惯对后代性状有极大影响。
而事实上，2006年美国科学家皮特尼克就通过解剖发现了，淫乱物种大脑小睾丸大，而贞洁物种大脑大睾丸小，推断淫乱物种智力低。
而这个发现不被社会重视（或者相关研究被黑暗民族封杀），原因就在于人们普遍有侥幸心理，认为淫乱降低后代智力的过程起码得有几万年，自己爽了再说，哪管它几万年后的事。
而这篇论文用无可辩驳的实验事实证明，你的生活习惯都可影响后代呢，淫乱降低后代智力哪用得了多久，你自己淫乱你的孩子就遭殃了。
而现在欧美日的民众普遍连个位数乘法都学不会的事实，更增加“淫乱降低后代智力”这一论断的说服力下面是该论文的译文。
因为我此前一直做的是中译英的工作，很少做英译中方向的翻译，并且国内甚少有相关研究，我没读过相应的中文资料，译文不可避免地有不完善的地方，请读者多多包涵！Ecology Letters, (2014) 17: 1545–1552Revisiting telegony: offspring inherit an acquired characteristic of their mother’s previous mate生态学通讯(2014) 17: 1545–1552 （此期刊最新的影响因子为10.772，算是仅次于世界顶级学术期刊的刊物了）重温先父遗传：后代继承他们母亲前配偶的获得性特征AbstractNewly discovered non-genetic mechanisms break the link between genes and inheritance, thereby also raising the possibility that previous mating partners could influence traits in offspring sired by subsequent males that mate with the same female (‘telegony’). In the fly Telostylinus angusticollis, males transmit their environmentally acquired condition via paternal effects on offspring body size. We manipulated male condition, and mated females to two males in high or low condition in a fully crossed design. Although the second male sired a large majority of offspring, offspring body size was influenced by the condition of the first male. This effect was not observed when females were exposed to the first male without mating, implicating semen-mediated effects rather than female differential allocation based on pre-mating assessment of male quality. Our results reveal a novel type of transgenerational effect with potential implications for the evolution of reproductive strategies.【摘要】新发现的非遗传机制打破了基因与遗传特征之间的联系，从而也提高了前配偶能影响由后继雄性与同一雌性交配授精所产后代的性状的可能性（先父遗传）。
关于基因英语作文
关于基因英语作文Title: Understanding Genetics: Exploring the Blueprintof Life。
Genetics is the study of genes, the fundamental unitsof heredity that determine the characteristics of living organisms. It plays a crucial role in various aspects of life, from the traits we inherit from our parents to the development of diseases and the potential for personalized medicine. In this essay, we delve into the fascinatingworld of genetics to understand its significance and implications.First and foremost, genes are segments of DNA (deoxyribonucleic acid) that contain the instructions for building and maintaining an organism. Each gene carries information for a specific trait, such as eye color, height, or susceptibility to certain diseases. The human genome, which is the complete set of genetic information in humans, comprises approximately 20,000 to 25,000 genes.Genetics encompasses several key concepts and processes, including inheritance, mutation, gene expression, and genetic variation. Inheritance refers to the passing oftraits from parents to offspring through the transmissionof genes. This process follows Mendelian principles of inheritance, which describe how traits are inherited according to dominant and recessive alleles.Mutation, on the other hand, is a spontaneous orinduced change in the DNA sequence of a gene. Mutations can occur due to various factors, such as environmental influences, radiation, or errors during DNA replication. While some mutations may have no noticeable effect, others can lead to genetic disorders or contribute to the development of diseases like cancer.Gene expression is the process by which informationfrom a gene is used to synthesize a functional product, typically a protein. This process involves several steps, including transcription, where the DNA sequence is copied into a molecule of messenger RNA (mRNA), and translation,where the mRNA is decoded to assemble the corresponding protein.Genetic variation refers to differences in the DNA sequences among individuals within a population or species. This variation is essential for evolution, as it provides the raw material for natural selection to act upon. Genetic variation can arise through mechanisms such as genetic recombination, gene flow, and random mutations.The study of genetics has far-reaching implications for various fields, including medicine, agriculture, and forensic science. In medicine, genetics plays a crucialrole in understanding the genetic basis of diseases and developing targeted therapies. For example, advancements in genetic testing have enabled the diagnosis and treatment of genetic disorders such as cystic fibrosis, sickle cell anemia, and Huntington's disease.Moreover, genetics holds promise for the field of personalized medicine, where treatments are tailored to an individual's genetic makeup. By analyzing a person'sgenetic profile, healthcare providers can predict theirrisk of developing certain diseases and prescribe medications that are most likely to be effective based on their genetic predispositions.In agriculture, genetics plays a vital role in crop improvement and animal breeding. Through selective breeding and genetic engineering techniques, scientists can develop crops and livestock with desirable traits such as increased yield, disease resistance, and nutritional content. This has significant implications for global food security and sustainability.In forensic science, genetics is used for various purposes, including identifying individuals based on DNA evidence, determining familial relationships, and solving crimes. DNA profiling, also known as DNA fingerprinting, has revolutionized criminal investigations by providing highly accurate and reliable evidence.Despite its immense potential, the field of genetics also raises ethical, legal, and social implications (ELSI).These include concerns about genetic privacy,discrimination based on genetic information, and the equitable distribution of genetic technologies and treatments. Addressing these challenges requires careful consideration of ethical principles, informed public dialogue, and robust regulatory frameworks.In conclusion, genetics is a fascinating and rapidly advancing field that holds the key to understanding the blueprint of life. From unraveling the mysteries of inheritance to unlocking the secrets of disease, genetics has revolutionized our understanding of biology and has the potential to transform various aspects of society. As we continue to explore the complexities of the genome, it is essential to approach the ethical, legal, and social implications of genetics with wisdom and foresight.。
七年级下册生物教材涵盖的主题和内容是什么？
七年级下册生物教材涵盖的主题和内容是什么？The theme and content covered in the seventh-grade biology textbook of the second semester are diverse and comprehensive. The topics covered in this textbook aim to provide students with a solid foundation in understanding the fundamental concepts and principles of biology.One of the main themes explored in the textbook is cell biology. Students will learn about the structure and function of cells, including the different organelles and their roles in cellular processes. They will also study cell division, exploring the processes of mitosis and meiosis, and understand how these processes contribute to growth, development, and reproduction.Another important topic covered in the textbook is genetics. Students will delve into the study of heredity, learning about genes, alleles, and how traits are passed down from parents to offspring. They will also explore the principles of Mendelian genetics and understand how Punnett squares can be used topredict the probability of certain traits in offspring.The textbook also covers the topic of ecology. Students will learn about ecosystems, food webs, and the interactions between organisms and their environment. They will explore concepts such as energy flow, nutrient cycling, and the impact of human activities on the environment. The importance of biodiversity and conservation will also be emphasized.Furthermore, the textbook includes sections on human biology, where students will learn about the different body systems and their functions. Topics such as the circulatory system, respiratory system, digestive system, and nervous system will be covered in detail. Students will also gain an understanding of common health issues and the importance of maintaining a healthy lifestyle.In addition to these core topics, the textbook also touches upon other areas of biology, such as evolution, classification of organisms, and the scientific method. Students will explore the evidence for evolution, learn about the different kingdoms and phyla, and understand the steps involved in conductingscientific experiments.Overall, the seventh-grade biology textbook provides students with a comprehensive overview of fundamental biology concepts. It aims to foster an appreciation for the natural world and develop critical thinking skills through hands-on activities, case studies, and real-life examples. By the end of the semester, students should have a solid foundation in biology and be well-prepared for further studies in the subject.中文回答：七年级下册生物教材涵盖的主题和内容非常多样且全面。
生物专业英语翻译--蒋悟生
核糖体的数量变化从几百到几千，核糖体是氨基酸组装成蛋白质的重要场所。
完整的核糖体由大亚基和小亚基组成。
核糖体沿着mRNA移动并阅读遗传密码，翻译成蛋白质。
一条mRNA上可能有多个核糖体，称多聚核糖体。
大多数细胞蛋白是由细胞质中核糖体生产。
输出蛋白和膜蛋白通常与内质网有关。
内质网，带有花边的生物囊，有管状，泡状之分，以及光滑和粗糙面区别。
两种都与蛋白质的合成和运输有关。
粗糙内质网上分布许多核糖体，也可能提供细胞分裂后所需的细胞膜。
光滑内质网上无核糖体，主要作用是脂肪和类固醇的合成以及细胞内有毒物质的氧化。
两种内质网合成的产物在其中进行分流或运输到细胞外。
运输小泡能够将可运输分子从内质网运输到高尔基复合体上。
在高尔基复合体中修饰，包装后输出细胞或传递到细胞质中的其他场所。
细胞中的液泡好象是中空的，但实际上充满了液体和可溶分子。
最典型的液泡存在于植物细胞中，储备水，糖以及其它分子。
动物中的液泡起吞噬和胞饮作用。
溶酶体是液泡亚单位，含有消化酶，降解大部分生物大分子。
消化食物微粒和降解损伤的细胞残片。
线粒体是细胞中化学产能的场所。
另外，植物细胞中的质体在光合作用中利用光能产生碳水化合物，线粒体内嵴上提供了很大的表面积并分布着产ATP酶。
线粒体自我复制，并且可能是自由生活的原核生物在进化中形成的后代。
质体有两种类型：白色体，缺乏色素，是淀粉，蛋白质和油的储备场所；色质体，含有色素。
叶绿体是最重要的色质体，含有与光合作用有关的叶绿素。
叶绿体的内部结构是由多层膜形成的叶绿体基粒，其中包埋在基质中的基粒称子座。
The Cytoskeleton（细胞骨架）所有的细胞都有细胞骨架，网络结构的纤丝充满了它所能触及的全部空间并且对细胞器提供支持作用。
细胞骨架大部分由微丝组成，微丝主要由可收缩的肌动蛋白组成。
动植物细胞的许多种类型细胞内运动与肌动蛋白有关。
第二类蛋白是肌球蛋白，它与肌肉细胞的收缩有关。
细胞骨架的另一个主要结构成分是微管，由球状的微管蛋白组成，象脚手架一般维持细胞的稳定形态。
《孟德尔随机化研究指南》中英文版
《孟德尔随机化研究指南》中英文版全文共3篇示例，供读者参考篇1Randomized research is a vital component of scientific studies, allowing researchers to investigate causal relationships between variables and make accurate inferences about the effects of interventions. One of the most renowned guides for conducting randomized research is the "Mendel Randomization Research Guide," which provides detailed instructions and best practices for designing and implementing randomized controlled trials.The Mendel Randomization Research Guide offers comprehensive guidance on all aspects of randomized research, from study design and sample selection to data analysis and interpretation of results. It emphasizes the importance of randomization in reducing bias and confounding effects, thus ensuring the validity and reliability of study findings. With clear and practical recommendations, researchers can feel confident in the quality and rigor of their randomized research studies.The guide highlights the key principles of randomization, such as the use of random assignment to treatment groups, blinding of participants and researchers, and intent-to-treat analysis. It also discusses strategies for achieving balance in sample characteristics and minimizing the risk of selection bias. By following these principles and guidelines, researchers can maximize the internal validity of their studies and draw accurate conclusions about the causal effects of interventions.In addition to the technical aspects of randomized research, the Mendel Randomization Research Guide also addresses ethical considerations and practical challenges that researchers may face. It emphasizes the importance of obtaining informed consent from participants, protecting their privacy and confidentiality, and ensuring the safety and well-being of study subjects. The guide also discusses strategies for overcoming common obstacles in randomized research, such as recruitment and retention issues, data collection problems, and statistical challenges.Overall, the Mendel Randomization Research Guide is a valuable resource for researchers looking to improve the quality and validity of their randomized research studies. By following its recommendations and best practices, researchers can conductstudies that produce reliable and actionable findings, advancing scientific knowledge and contributing to evidence-based decision making in various fields.篇2Mendel Randomization Study GuideIntroductionMendel Randomization Study Guide is a comprehensive and informative resource for researchers and students interested in the field of Mendel randomization. This guide provides anin-depth overview of the principles and methods of Mendel randomization, as well as practical advice on how to design and conduct Mendel randomization studies.The guide is divided into several sections, each covering a different aspect of Mendel randomization. The first section provides a brief introduction to the history and background of Mendel randomization, tracing its origins to the work of Gregor Mendel, the father of modern genetics. It also discusses the theoretical foundations of Mendel randomization and its potential applications in causal inference.The second section of the guide focuses on the methods and techniques used in Mendel randomization studies. This includesa detailed explanation of how Mendel randomization works, as well as guidelines on how to select instrumental variables and control for potential confounders. It also discusses the strengths and limitations of Mendel randomization, and provides practical tips on how to deal with common challenges in Mendel randomization studies.The third section of the guide is dedicated to practical considerations in Mendel randomization studies. This includes advice on how to design a Mendel randomization study, collect and analyze data, and interpret the results. It also provides recommendations on how to report Mendel randomization studies and publish research findings in scientific journals.In addition, the guide includes a glossary of key terms and concepts related to Mendel randomization, as well as a list of recommended readings for further study. It also includes case studies and examples of Mendel randomization studies in practice, to illustrate the principles and techniques discussed in the guide.ConclusionIn conclusion, the Mendel Randomization Study Guide is a valuable resource for researchers and students interested in Mendel randomization. It provides a comprehensive overview ofthe principles and methods of Mendel randomization, as well as practical advice on how to design and conduct Mendel randomization studies. Whether you are new to Mendel randomization or looking to deepen your understanding of the field, this guide is an essential reference for anyone interested in causal inference and genetic epidemiology.篇3"Guide to Mendelian Randomization Studies" English VersionIntroductionMendelian randomization (MR) is a method that uses genetic variants to investigate the causal relationship between an exposure and an outcome. It is a powerful tool that can help researchers to better understand the underlying mechanisms of complex traits and diseases. The "Guide to Mendelian Randomization Studies" provides a comprehensive overview of MR studies and offers practical guidance on how to design and carry out these studies effectively.Chapter 1: Introduction to Mendelian RandomizationThis chapter provides an overview of the principles of Mendelian randomization, including the assumptions andlimitations of the method. It explains how genetic variants can be used as instrumental variables to estimate the causal effect of an exposure on an outcome, and outlines the key steps involved in conducting an MR study.Chapter 2: Choosing Genetic InstrumentsIn this chapter, the guide discusses the criteria for selecting appropriate genetic instruments for Mendelian randomization. It covers issues such as the relevance of the genetic variant to the exposure of interest, the strength of the instrument, and the potential for pleiotropy. The chapter also provides practical tips on how to search for suitable genetic variants in public databases.Chapter 3: Data Sources and ValidationThis chapter highlights the importance of using high-quality data sources for Mendelian randomization studies. It discusses the different types of data that can be used, such asgenome-wide association studies and biobanks, and offers advice on how to validate genetic instruments and ensure the reliability of the data.Chapter 4: Statistical MethodsIn this chapter, the guide explains the various statistical methods that can be used to analyze Mendelian randomization data. It covers techniques such as inverse variance weighting, MR-Egger regression, and bi-directional Mendelian randomization, and provides guidance on how to choose the most appropriate method for a given study.Chapter 5: Interpretation and ReportingThe final chapter of the guide focuses on the interpretation and reporting of Mendelian randomization results. It discusses how to assess the strength of causal inference, consider potential biases, and communicate findings effectively in research papers and presentations.ConclusionThe "Guide to Mendelian Randomization Studies" is a valuable resource for researchers who are interested in using genetic data to investigate causal relationships in epidemiological studies. By following the guidance provided in the guide, researchers can enhance the rigor and validity of their Mendelian randomization studies and contribute to a better understanding of the determinants of complex traits and diseases.。
Mendelian Genetics
Mendelian Genetics
Genes and The Environment
• The product of a genotype is generally not a rigidly defined phenotype, but a range of phenotypic possibilities, the norm of reaction, that are determined by the environment. – In some cases the norm of reaction has no breadth (for example, blood type). • Norms of reactions are broadest for polygenic characters. • For these multifactorial characters, the environment contributes to their quantitative nature.
Normal Aa
a Aa Normal (carrier) aa Albino
a
Cystic Fibrosis
Cystic fibrosis
• One in 25 whites of European ancestry is a carrier, 1 in 2500 is affected. • The normal allele codes for a membrane protein that transports Cl- between cells and the environment. • If these channels are defective or absent, there are abnormally high extracellular levels of chloride that causes the mucus coats of certain cells to become thicker and stickier than normal. • This mucus build-up in the pancreas, lungs, digestive tract, and elsewhere favors bacterial infections. • Without treatment, affected children die before five, but with treatment can live past their late 20’s or even longer.
全基因组拷贝数变异测序检测胎儿生长受限染色体异常的诊断价值
ＤＯＩ：１０．１３６０２／ｊ．ｃｎｋｉ．ｊｃｌｓ．２０２０．１２．０２·临床检验技术研究·全基因组拷贝数变异测序检测胎儿生长受限染色体异常的诊断价值罗小金１，郭岩芸２，黄和明１，韦升市１，刘金星１，陈婧１，曹宪振１，欧德标１，白江涛１（１．深圳市龙岗区妇幼保健院中心实验室，广东深圳５１８１７２；２．深圳市龙岗区人民医院妇产科，广东深圳５１８１７２）摘要：目的 探讨低深度全基因组拷贝数变异测序（ｃｏｐｙｎｕｍｂｅｒｖａｒｉａｔｉｏｎｓｅｑｕｅｎｃｉｎｇ，ＣＮＶ Ｓｅｑ）与核型分析技术在检测产前孕中晚期胎儿生长受限（ｆｅｔａｌｇｒｏｗｔｈｒｅｓｔｒｉｃｔｉｏｎ，ＦＧＲ）染色体异常中的临床诊断价值。
方法 对２０１８年４月至２０２０年１０月因ＦＧＲ行侵入性产前诊断分析的１３８例胎儿同时进行Ｇ显带核型分析和全基因组ＣＮＶ Ｓｅｑ检测，结合短串联重复序列（ＳＴＲ）检测鉴别母体污染。
结果 １３８例ＦＧＲ病例中，采用Ｇ显带核型分析检出＞１０Ｍｂ染色体异常１２例（８．７％，１２／１３８），采用ＣＮＶ Ｓｅｑ检出９例（６．５％，１２／１３８）＞１０Ｍｂ染色体异常，２例平衡易位和１例低比例嵌合体。
Ｇ显带核型分析检出＜１０Ｍｂ染色体异常１例，ＣＮＶ Ｓｅｑ额外检出＜１０Ｍｂ染色体ＣＮＶｓ１１例（８．０％，１１／１３８），其中８例为致病性ＣＮＶｓ（包括２例Ｗｉｌｌｉａｍｓ Ｂｅｕｒｅｎ综合征、２例１６ｐ微缺失／微重复综合征、１例为Ｍｉｌｌｅｒ Ｄｉｅｋｅｒ综合征、１例Ｗｏｌｆ Ｈｉｒｓｃｈｈｏｒｎ综合征、１例３ｑ２９缺失综合征和１例父源单亲二倍体），３例为临床意义不明拷贝数变异（ｖａｒｉａｎｔｓｏｆｕｎｃｅｒｔａｉｎｓｉｇｎｉｆｉｃａｎｃｅ，ＶＯＵＳ）。
结论 与传统Ｇ显带核型分析相比较，ＣＮＶ Ｓｅｑ除可有效检出产前ＦＧＲ中＞１０Ｍｂ且涉及ＣＮＶｓ的染色体数目和结构异常外，还可额外检出核型正常ＦＧＲ中＜１０Ｍｂ的染色体ＣＮＶ，可更系统全面地揭示产前ＦＧＲ的遗传学病因，科学指导ＦＧＲ胎儿妊娠选择。
遗传英语作文
遗传英语作文In the realm of biology genetics is a fascinating field that explores the inheritance of traits from one generation to the next. Heres an essay on genetics that delves into its definition significance and some of the key concepts.Title The Wonders of Genetics Understanding Our Inherited TraitsIntroductionGenetics is the branch of biology that studies the patterns of inheritance of traits from parents to offspring. It is a cornerstone of modern biology providing insights into the mechanisms that govern the transmission of hereditary information. This essay aims to explore the fundamental principles of genetics its importance in various fields and the ethical considerations that arise from genetic research.Definition of GeneticsAt its core genetics is the study of genes which are segments of DNA that carry the instructions for making proteins. These proteins are the building blocks of the body and are responsible for the characteristics we inherit from our parents. Genetics helps us understand how these traits are passed down through generations and how variations in genes can lead to differences in physical appearance susceptibility to diseases and more. Key Concepts in Genetics1. Mendelian Inheritance Named after Gregor Mendel the father of modern genetics Mendelian inheritance is the basic pattern by which traits are passed from parents to offspring. Mendels laws of segregation and independent assortment describe how alleles different forms of a gene are separated and distributed during the formation of gametes.2. DNA Structure and Function Deoxyribonucleic acid DNA is the molecule that carries genetic information. It is composed of two strands that coil around each other to form a double helix. The sequence of nucleotide bases adenine thymine cytosine and guanine in DNA determines the genetic code.3. Gene Expression This is the process by which the information in a gene is used to synthesize a functional gene product such as a protein. Gene expression is regulated by various mechanisms and can be influenced by environmental factors.4. Mutations A mutation is a change in the DNA sequence. While many mutations areharmless some can lead to genetic disorders or alter an organisms traits.5. Chromosomes Genes are organized on structures called chromosomes which are found in the nucleus of cells. Humans typically have 46 chromosomes arranged in 23 pairs. Significance of GeneticsGenetics plays a crucial role in various aspects of life and society. It is essential inMedicine Understanding the genetic basis of diseases can lead to better treatments and preventive measures.Agriculture Genetic knowledge helps in developing crops that are more resistant to diseases and environmental stresses.Forensic Science DNA fingerprinting is used to solve crimes and establish paternity.Conservation Biology Genetic studies can inform conservation efforts by revealing the genetic diversity and relatedness of species.Ethical ConsiderationsThe power of genetic knowledge also brings ethical challenges. Issues such as genetic privacy the potential for genetic discrimination and the implications of genetic engineering are subjects of ongoing debate.ConclusionGenetics is a field of immense importance and potential. As we continue to unravel the complexities of our genetic code we gain the power to address some of humanitys most pressing challenges. However with this power comes the responsibility to navigate the ethical landscape carefully ensuring that the benefits of genetic research are shared equitably and do not infringe upon fundamental rights.Further ReadingFor those interested in delving deeper into the subject The Double Helix by James D. Watson provides a historical account of the discovery of the DNA structure while The Gene An Intimate History by Siddhartha Mukherjee offers a comprehensive look at the history and future of genetics.。
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Homework: pg. 274, problems 1 – 5
Section 11.3 Exploring Mendelian Genetics
Dihybrid Cross
round yellow wrinkled green
– study two pairs of alleles (two traits) at the same time – e.g.: seed color & seed shape
RR
Rr
Rr
rr
Complete Dominance
Cross Genotype ratio Phenotype ratio
Rr x Rr
RR: Rr: rr (1:2:1)
dominant: recessive (3:1)
Incomplete Dominance
Cross Genotype Phenotype ratio ratio
genotype
or
IB IB
or
IA IB
AB
ii
O
IA i
phenotype phenotype A
IB i
B
• Multiple Alleles
Full
– One gene has more than two alleles (in the population, not in a single organism). – e.g.: rabbit coat color, four alleles:
Beyond Dominant and Recessive Alleles
• Incomplete Dominance
RR rr
– One allele is not completely dominant over the other.
Rr
– Offspring show a blending of traits. – e.g.: Crossing a white flower with a red flower yields a pink flower.
Rr x Rr
RR: Rr: rr dominant: blending: recessive (1:2:1) (1:2:1)
• Codominance
– Both alleles contribute to the phenotype. – e.g.: roan cow – e.g.: blood type IA IA
round yellow
round round wrinkled wrinkled yellow green yellow green Number Ratio
• Dihybrid Cross
– P: YYRR, yyrr – F1: YyRr – F2:
• 9 genotypes • 4 phenotypes (9:3:3:1)
Independent Assortment
Alleles for different traits can segregate independently during gamete formation.
Summary of Mendel’s Principles
• The inheritance of biological characteristics is determined by genes. • In cases where there’s more than one allele for a particular gene, some alleles may be dominant and some may be recessive. • Most sexually reproducing organisms have two copies of each gene – one from each parent. These copies separate during gamete formation. • Alleles for different genes segregate independently.
• C > cБайду номын сангаасh > ch > c
– e.g.: blood type, three alleles
• IA = IB > i
• Polygenic Traits
– If more than one gene controls a trait, that trait is a polygenic trait. – e.g.: skin color, height, eye color