Polygenic inheritance involves multiple genes contributing to a trait, as opposed to single-gene inheritance. It can result in continuous variation, where a wide range of phenotypes exist between extremes. Human skin color and wheat seed color are examples of polygenic traits that show continuous variation, with skin color determined by 3-4 genes influencing melanin production and seed color by 3 genes determining red pigment levels.
This PPT consists of 15 slides only explaining Pleiotropy. This is a phenomenon when one gene controls more than one trait , the traits may be related .Generally one gene's product acts for many reactions and so can affect more than one trait. Examples can be seen in pea Coloured flower and pigmentation in leaf axil, frizzle trait in chicken, fur colour and deafness in cats,Human pleiotropic traits are PKU,Sickle cell Anaemia. HOsyndrome , p53 gene etc
This PPT consists of 15 slides only explaining Pleiotropy. This is a phenomenon when one gene controls more than one trait , the traits may be related .Generally one gene's product acts for many reactions and so can affect more than one trait. Examples can be seen in pea Coloured flower and pigmentation in leaf axil, frizzle trait in chicken, fur colour and deafness in cats,Human pleiotropic traits are PKU,Sickle cell Anaemia. HOsyndrome , p53 gene etc
Epistasis is a Greek word that means standing over .Bateson used it to describe the masking effect in 1909.
An interaction between a pair of loci in which the phenotype effect of one locus depends on the genotype at the second locus.
Genes whose phenotypes are ;
Expressed,epistatic.
Altered or suppressed hypostatic.
Introduction :
Mendel and subsequent workers assumed that a character was governed by a single gene.
But it was later discovered that many characters in almost all the organisms are governed by two or more genes. Such gene affect the development of concerned characters in various ways.
The phenomenon of two or more gene affecting the expression of each other in various ways in the development of a single character of on organism is known as gene interaction.
It is the fundamental law of population genetics and provides the basis for studying Mendelian populations ( Mendelian population: A group of sexually inbreeding organisms living within a circumscribed area). It describes populations that are not evolving.
Inability of a plant with functional pollen to set seed when self-pollinated.
Hindrance to self-fertilization.
Prevents inbreeding and promotes outcrossing.
Reported in about 70 families of angiosperms including crop species.
This PPT consists of 24 slides explaining Polygenic Inheritance . Some traits are controlled by two or more genes. These traits differ from Mendelian traits and donot show discrete alternative or contrasting forms and show continuous ranges. Examples of such traits are wheat seed colour, plant height, Human skin colour controlled by at least three genes showing many shades of dark and fare, human height, human eye colour etc
According to Hardy (England,1908) and Weinberg (Germany,1909), gene and genotype frequency of a Mendelian population remain constant generation after generation unless there is selection,mutation,migration or random drift.
For the IB Biology course. To get the editable pptx file, please make a donation to one of my chosen charities. More information: http://sciencevideos.wordpress.com/about/biology4good/
For the IB Biology course. To be sent the file, please make a donation to one of my chosen charities at Biology4Good. More information here: http://sciencevideos.wordpress.com/about/biology4good/
Epistasis is a Greek word that means standing over .Bateson used it to describe the masking effect in 1909.
An interaction between a pair of loci in which the phenotype effect of one locus depends on the genotype at the second locus.
Genes whose phenotypes are ;
Expressed,epistatic.
Altered or suppressed hypostatic.
Introduction :
Mendel and subsequent workers assumed that a character was governed by a single gene.
But it was later discovered that many characters in almost all the organisms are governed by two or more genes. Such gene affect the development of concerned characters in various ways.
The phenomenon of two or more gene affecting the expression of each other in various ways in the development of a single character of on organism is known as gene interaction.
It is the fundamental law of population genetics and provides the basis for studying Mendelian populations ( Mendelian population: A group of sexually inbreeding organisms living within a circumscribed area). It describes populations that are not evolving.
Inability of a plant with functional pollen to set seed when self-pollinated.
Hindrance to self-fertilization.
Prevents inbreeding and promotes outcrossing.
Reported in about 70 families of angiosperms including crop species.
This PPT consists of 24 slides explaining Polygenic Inheritance . Some traits are controlled by two or more genes. These traits differ from Mendelian traits and donot show discrete alternative or contrasting forms and show continuous ranges. Examples of such traits are wheat seed colour, plant height, Human skin colour controlled by at least three genes showing many shades of dark and fare, human height, human eye colour etc
According to Hardy (England,1908) and Weinberg (Germany,1909), gene and genotype frequency of a Mendelian population remain constant generation after generation unless there is selection,mutation,migration or random drift.
For the IB Biology course. To get the editable pptx file, please make a donation to one of my chosen charities. More information: http://sciencevideos.wordpress.com/about/biology4good/
For the IB Biology course. To be sent the file, please make a donation to one of my chosen charities at Biology4Good. More information here: http://sciencevideos.wordpress.com/about/biology4good/
Which statement describes a similarity between the diploid and haplo.pdfarpitcollections
Which statement describes a similarity between the diploid and haploid phases of plant life?
A zygote is formed ____.
Human skin color is an example of ____, while sickle-cell anemia is an example of ____.both
are multicellular
Solution
1. both are multicellular.
The plant life cycle alternates between haploid and diploid generations.Plants have multicellular
haploid and multicellular diploid stages in their life cycle.Gametes develop in the multicellular
haploid gametophyte.Fertilization gives rise to a multicellular diploid sporophyte,which
produces haploid spores via meiosis.
2.Zygote is formed by the fusion of egg and sperm nuclei.
In human fertilization,ovum which is a haploid secondary oocyte and a haploid sperm cell
combine to form a single 2n diploid cell called the zygote.
In fungi,the sexual fusion of haploid cells is called karyogamy.This cell may then enter meiosis
or mitosis depending on the life cycle of the species.
In plants,the zygote may be polyploid if fertilization occurs between meiotically unreduced
gametes.
Somatic cells are other than reproductive cells.Zygote formation occurs in reproductive cells.
3.Human skin color is an example of polygenic inheritance, while sickle-cell anemia is an
example of pleiotropy.
Polygenic inheritance occurs when one characteristic is controlled by two or more genes.Skin
color is largely determined by the amount of melanin. Dark skinned individuals produce more
melanin than light skinned individuals.At least three genes regulate the amount of melanin
produced. Each gene has two forms: dark skin allele (A,B,and C) and light skin allele (a,b,and c).
Pleiotropy occurs when variation at a single gene locus affects multiple aspects of the
phenotype.Sickle cell anemia is a genetic disease that causes deformed red blood cells with a
rigid,crescent shape instead of the normal flexible,round shape.It is caused by a change in one
nucleotide in the HBB gene.Sickle cell anemia occurs when the HBB gene mutation causes both
beta-globin subunits of hemoglobin to change into hemoglobin S..
Example OneDiscuss how new discoveries in genetics are contr.docxSANSKAR20
Example One
Discuss how new discoveries in genetics are contributing to our understanding of the HIV virus
and how some folks exposed to HIV have been able to escape developing AIDS.
The HIV virus daily infects 14,000 people, however some individuals’ odds of contracting the
virus are very low. Dr. Donald Mosier of the Script Institute was puzzled by this and launched a
genetic study to determine why certain individuals are resistant to the HIV virus. What Dr.
Mosier discovered was the resistant people inherited a deletion mutation that gave them
protection. Within the deletion mutation, the receptor CCR5, is excluded. This deleted section
of the CCR5 receptor functions as a lock, therefore people born with the mutation will not get
the HIV virus. Those individuals that are homozygous – have two copies of the same deletion
gene, are immune to the virus and are protected. Individuals that are heterozygous – have two
different genes – have some protection from HIV because their body have half the “locks.” Dr.
Mosier further studied populations and discovered the deleted mutation was higher in certain
parts of the world and among Caucasians.
Explain the genetic connection between phenotype and genotype discovered by Mendel in the
19th century.
Genetics helps to understand human diversity, not only in today’s world but in the past as well.
When studying genetics it is important to understand the relationship between phenotype and
genotype. A phenotype is defined as an observable physical characteristic whereas a genotype
is the set of specific genes an organism carries (Allen, Anton, Stanford 60). In the video lesson,
Anne Stone commented the phenotype can be impacted by the environment. For example, if
there is not sufficient food or there is disease, this can impact an individual’s height which is a
phenotype. Anthropologist Geneticist Joanna Mountain explained a phenotype can be
“measurements and anything we can describe about a person from appearance to metabolism.”
Utilizing the garden pea plant to conduct his experiment, Gregor Mendel was able to recognize
traits were passed on from parents to offspring. He knew traits were inherited but did not know
how this inheritance worked. Mendel’s Principles of Segregation which states in an organism,
alleles occurs in pairs and when gametes sex cells get produced, alleles separate so each
gamete contains one member of each pair. Further experiments by Mendel lead him to
conclude in a unit of inheritance, meaning offspring received receive genes from each parent.
Theses principles laid the foundation for future scientists to study inheritance.
Vocabulary
Phenotype – observable characteristics; expression of genetic instructions; something you can
measure
Genotype – genetic make-up of an individual; every person has a unique genotype made of
genes inherited from parents
Recessive – a masked trait or covered up
Dominant – mask recessive characteristics
P ...
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
2. Polygenic Inheritance
10.3.1 Define polygenic inheritance.
10.3.2 Explain that polygenic inheritance can contribute to
continuous variation using two examples, one of which
must be human skin colour.
3. Polygenic Inheritance
So far, the characteristics we have studied have been
controlled by one gene.
Some characteristics are controlled by more than one
gene.
This is called Polygenic Inheritance.
Examples of traits controlled by polygenic inheritance
include:
skin colour, eye colour, seed colour in wheat,
4. Polygenic Inheritance
It is important not to confuse multiple alleles with
polygenic inheritance.
Blood type is an example of multiple alleles, whereby
blood type is controlled by three possible alleles (IA
, IB
, i)
all occurring at one locus.
Polygenic inheritance involves many genes at several
different loci.
5. Continuous vs Non-continuous Variation
Variation is expressed by the different phenotypes for a
characteristic.
Variation can be:
Continuous.
Exhibits a wide range of phenotypes ranging from one extreme to
the other.
Discontinuous.
Usually only has 2 forms.
Polygenic Inheritance can contribute to continuous
variation.
6. Human Skin Colour
Human skin colour is a result of polygenic inheritance.
Skin colour is controlled by 3 or 4 genes.
Skin colour depends on the amount of a black pigment
called melanin present.
Each gene has alleles which promote melanin production
and alleles which do not.
Thus there is a wide range of phenotypes possible ranging
from all alleles promoting melanin production (black
Skin) to non alleles promoting melanin production (white
skin).
7. Continuous Variation in Human Skin
Colour as a Result of Polygenic
Inheritance Ref: Yr12 Biology, Biozone
8. Seed Colour in Wheat
Seed colour in wheat is also the result of polygenic
inheritance.
Seed colour is controlled by 3 genes, each on a different
chromosome.
Each gene has two alleles, coding for the production of a
red pigment or not.
Thus a seed can have up to 6 red alleles.
Seed colour exhibits continuous variation, with seed
colours ranging from dark red to white.
11. IBO guide:
10.3.1 Define polygenic inheritance.
10.3.2 Explain that polygenic inheritance can contribute to
continuous variation using two examples, one of which
must be human skin colour.
12. IBO guide:
Aim 8: This is one of the most obvious opportunities to
develop the theme of parity of esteem for all humans. The
selective advantage of dark skin to protect against
ultraviolet light and light skin to allow vitamin D
production could be mentioned. The correlation between
skin colour and intensity of sunlight is clear, though the
selective advantages of particular skin colours can now be
overcome by the use of sun-block creams and vitamin D
supplements.
