FEATURING THE SUMMARY OF SCIENCE 10 UNIT 3 MODULE 2.
INCLUDING RNA AND DNA
GENETIC ENGINEERING
HUMAN KARYOTYPING
DOWNS SYNDROME
CRI DU CHAT
EDWARDS SYNDROME
CHROMOSOME ABNORMALITIES
TRAITS INHERITED
A PowerPoint Presentation for Grade 9 teachers. This presentation is ONLY suggested guide for teachers to assist them on the discussion after the activities as suggested in the Learner's Module were performed. Please feel free to add comments and suggestions. Thanks!
FEATURING THE SUMMARY OF SCIENCE 10 UNIT 3 MODULE 2.
INCLUDING RNA AND DNA
GENETIC ENGINEERING
HUMAN KARYOTYPING
DOWNS SYNDROME
CRI DU CHAT
EDWARDS SYNDROME
CHROMOSOME ABNORMALITIES
TRAITS INHERITED
A PowerPoint Presentation for Grade 9 teachers. This presentation is ONLY suggested guide for teachers to assist them on the discussion after the activities as suggested in the Learner's Module were performed. Please feel free to add comments and suggestions. Thanks!
My notes for 9th grade, 2nd Quarter. Consists of multiple lessons in Science from the History of the Atomic Model to Electron Dot Structure. To be honest, I got lazy in making this halfway there. Sorry. ^^u
My notes for 9th grade, 2nd Quarter. Consists of multiple lessons in Science from the History of the Atomic Model to Electron Dot Structure. To be honest, I got lazy in making this halfway there. Sorry. ^^u
Assignment Details
Open Date
Apr 2, 2018 12:05 AM
Graded?
Yes
Points Possible
100.0
Resubmissions Allowed?
No
Attachments checked for originality?
Yes
Top of Form
Assignment Instructions
Develop a chart or diagram that will illustrate how prenatal development is influenced by environmental or genetic factors. Creativity is strongly suggested. There is no requirement for APA format in this assignment. There is no requirement of references for this assignment.
Supporting Materials
·
308 Assignment 2. Rubric.doc
(50 KB)
Bottom of Form
Nature and Nurture: Genetic and Environmental Foundations of Child Development
Child development is impacted by both genetic or inherited factors and environmental factors. Genetic factors are inherited from both parents at the time of conception, but can be the result of different types of gene interactions. Environmental factors impact different ways families function and children develop. Environmental factors include the ecological systems that may alter family function, socio-economic status and cultural values and public policy.
TOPICS COVERED WILL INCLUDE:
· Genetics
· Family functioning from an ecological systems perspective
· The impact of
socioeconomic status
· Cultural values and public policies
“
Toddler hopscotch
” by
Ilya Haykinson
is licensed under
CC BY 2.0
The Influence of Alleles
In the argument over nature versus nurture in child development, nature is determined by genes passed down from parent to child during conception. Both parents pass genetic traits to their offspring, but different offspring may acquire different traits from each parent. Why do some children in one family have similar characteristics or appearances and yet other children in the same family look very different? The answer lies in the interaction of genes inherited from the mother and father.
Genes and alleles influence the inheritance of traits, through dominant–recessive inheritance, incomplete dominance, X-linked inheritance, genomic imprinting,
mutation
, and
polygenic inheritance
. In order to understand genetic inheritance, you need to understand the basics of how genes work, and how they work together with one another.
Fundamental Definitions
Understanding the basic structures and elements of genetics is essential to recognize how various traits are inherited, from appearance to intelligence.
GENE
The basic building block of the study of genetics is the gene; a gene is a single unit of genetic information.
CHROMOSOME
A chromosome is a threadlike strand of DNA encoded with a large number of genes. Humans receive 23 chromosomes from each parent, for a total of 46 chromosomes.
ALLELE
An
allele
is one of a pair of genes that appear at a particular location on a particular chromosome and control the same characteristics in the individual. Humans have two alleles, one from each parent, at each genetic locus, or position, on a chromosome.
GENOTYPE
The entire ...
Assignment Details
Open Date
Apr 2, 2018 12:05 AM
Graded?
Yes
Points Possible
100.0
Resubmissions Allowed?
No
Attachments checked for originality?
Yes
Top of Form
Assignment Instructions
Develop a chart or diagram that will illustrate how prenatal development is influenced by environmental or genetic factors. Creativity is strongly suggested. There is no requirement for APA format in this assignment. There is no requirement of references for this assignment.
Supporting Materials
· 308 Assignment 2. Rubric.doc (50 KB)
Bottom of Form
Nature and Nurture: Genetic and Environmental Foundations of Child Development
Child development is impacted by both genetic or inherited factors and environmental factors. Genetic factors are inherited from both parents at the time of conception, but can be the result of different types of gene interactions. Environmental factors impact different ways families function and children develop. Environmental factors include the ecological systems that may alter family function, socio-economic status and cultural values and public policy.
TOPICS COVERED WILL INCLUDE:
· Genetics
· Family functioning from an ecological systems perspective
· The impact of socioeconomic status
· Cultural values and public policies
“Toddler hopscotch” by Ilya Haykinson is licensed under CC BY 2.0
The Influence of Alleles
In the argument over nature versus nurture in child development, nature is determined by genes passed down from parent to child during conception. Both parents pass genetic traits to their offspring, but different offspring may acquire different traits from each parent. Why do some children in one family have similar characteristics or appearances and yet other children in the same family look very different? The answer lies in the interaction of genes inherited from the mother and father.
Genes and alleles influence the inheritance of traits, through dominant–recessive inheritance, incomplete dominance, X-linked inheritance, genomic imprinting, mutation, and polygenic inheritance. In order to understand genetic inheritance, you need to understand the basics of how genes work, and how they work together with one another.
Fundamental Definitions
Understanding the basic structures and elements of genetics is essential to recognize how various traits are inherited, from appearance to intelligence.
GENE
The basic building block of the study of genetics is the gene; a gene is a single unit of genetic information.
CHROMOSOME
A chromosome is a threadlike strand of DNA encoded with a large number of genes. Humans receive 23 chromosomes from each parent, for a total of 46 chromosomes.
ALLELE
An allele is one of a pair of genes that appear at a particular location on a particular chromosome and control the same characteristics in the individual. Humans have two alleles, one from each parent, at each genetic locus, or position, on a chromosome.
GENOTYPE
The entire genetic makeup of an individual is called the genotype. The geno ...
Lec 02 Factors influencing Human Growth and DevelopmentDr. Imran A. Sajid
These slides are prepared for students of BS Social Work. Social Workers come across clients in different age groups and categories. This subject helps them put the client into social, physical, psychological, and emotional perspectives.
Dr. Imran A. Sajid
Department of Social Work, University of Peshawar, Pakistan
Genetics is the science of studying how living things pass on characteristics or traits and its variations in their cell make-up from one generation to the other.
Genetic and Environmental FoundationsChapter 2.docxbudbarber38650
Genetic and Environmental Foundations
Chapter 2
Where do we start? What is inherited from our parents and their ancestors and what role does environment contribute? These are but a few of the questions that this chapter will explore.
1
Heredity
DNA
Chromosomes
Genes
Meiosis
Mitosis
Heredity defines one’s nature – which based on the biological transmission of traits and characteristics from one generation to another. The structures we inherit both make our behaviors possible and places limits on them.
Genetic (inherited) influences are fundamental in the transmission of physical traits, such as height, hair texture, and eye color. Genetics also appears to be a factor in intelligence and in the origins of personality traits such as activity level, sociability, shyness, fearfulness etc. Genetic influences are also implicated in psychological problems and disorders such as anxiety and depression, dependence on nicotine and alcohol etc.
Chromosomes and genes – rod shaped structures found in cells. A normal human cell contains 46 chromosomes organized into 23 pairs. Each chromosome contains thousands of segments called genes. Genes carry the biochemical materials that regulate the development of traits. Polygenic – some traits are determined by the combination of pairs of genes.
We begin life as a single cell or zygote. There are 2 types of cell division.
Mitosis – cell division process by which growth occurs and tissues are replaced. Through mitosis, genetic code is carried into new cells in our bodies.
Sperm and ova are produced through meiosis, or reduction division. In meiosis the 46 chromosomes within the cell first line up into 23 pairs. The DNA ladders then unzip, leaving unpaired chromosome halves. As a consequence each new cell only contains 23 chromosomes.
2
Fertilization
Union of egg and sperm
Zygote
Union of egg and sperm - please note sperm with y sex chromosomes seem to swim faster then x one of the reason more boys are conceived then girls. Male fetuses suffer higher rate of spontaneous abortion usually during the first month of pregnancy. Boys also higher rate of infant mortality
The resulting fertilized egg is called a zygote.
3
Male or Female
Autosomes
Twenty-third pair (sex chromosomes)
XX
XY
When a sperm cell fertilizes an ovum we receive 23 from each which combine for the 23 pairs. Twenty-two of the pairs are autosomes – pair that look alike and possess genetic information concerning the same set of traits.
The 23rd pair consists of the sex chromosomes which look different and determine our sex. Males are XY and females are XX
4
Multiple Births
How they occur
Dizygotic twins
Monozygotic twins
Monozygotic or identical twins – one egg fertilized and then the zygote divides into 2.
Dizygotic twins – two eggs fertilized by different sperm.
MZ twins occur with equal frequency in all ethnic groups – but for DZ incidence does vary. European Americans.
Similar to Heredity, inheritance, and variation (20)
lesson for grade 9 science
the topics includes: (a)respiratory system, (b) circulatory system, (c) other organs working together with the respiratory and circulatory system
An introduction to the study of World Geography.
a) meaning of geography
b) essential elements of geography
c) branches of geography
d) themes of geography
e) graphic representation of the Earth (maps)
f) the global grid system
g) types of maps
h) map essentials
i) earth as a member of the solar system
j) the Planet Earth
k) evaluation (Quiz)
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
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.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
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
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.
2. Appreciate Similarities and
Differences Among Organisms
What characteristics do you share among all human species?
What characteristics do you share among your siblings?
What characteristics do you share among your close relatives?
Which traits resemble your parent/s?
Which traits neither resemble your mom’s or your dad’s?
Have you been told that you have your mother’s nose or your
grandmother’s eyebrows?
3. Examine closely the picture of a family, what
characteristics do these siblings share in
4. People have been fascinated at how children
will resemble their parents and vice versa.
As years went by, scientists began to search
for more information on how these traits are
passed on.
The passing of traits from parents to offspring
is HEREDITY and the science that deals
with the study of heredity is GENETICS.
5. The family picture shows how some traits of the parents
blend into the traits of the offspring.
Can you name some of the traits?
6. Nature Versus Nurture
Human grow and develop according to the instructions in our
GENES.
The Human Genome Project (HGP -1987-2003) was aimed to map
out the sequence of the genes that will benefit many fields including
medicine and human evolution.
The findings concluded that there are about 20,000 genes that shape
how humans develop.
But despite this big number, it is very difficult to separate the relative
influence of heredity and environment on an individual’s
characteristics.
Human development is not just genetic.
7. The girl and boy in the picture may have had their father’s eye but
got their mother’s lips.
The uniqueness is brought about by the combination of genes of
their parents.
8. How will the environment influence
their inherited traits?
The environment may influence an individual’s growth and
development.
Height is determined by genes. Tall parents will likely
produce tall children.
However, inadequate nutrition and lack of sleep may lead
to stunted growth.
In similar way, intelligence which includes the speed of
processing information has been studied to be genetically
controlled.
9. But even if a person is predisposed to
become intelligent, if the environment in
which he or she grows up in is not
stimulating, the person may not reach his full
potential.
Similarly, a person may not have the perfect
combination of genes for intelligence, but if
the environment motivates and nurtures
learning, the person may develop higher
intelligence quotient.
10. Check Your Understanding
1.Why does father or mother who paints well
will likely have children who are excellent
painters as well?
2.Two identical twins (twins who look exactly
alike and come from the same fertilized egg;
same genetic make-up; same sex) were
separated at birth. One was adopted by a rich
family and the other by a poor sidewalk vendor.
How will this scenario affect the twins?
11. Traits are observable characteristics determined by
specific segments of DNA called GENES.
The DNA
(deoxyribonucleic acid) is
a double helix molecule,
the thin strands of which
are twisted around each
other like a twisted ladder.
The sides of the ladder are
made up of sugar and
phosphate molecules and
the steps of the ladder are
made of nitrogen base
pairs.
12. A GENE is a length of DNA that codes for a
particular protein.
For example, a gene may code for the protein of
your hair or a protein like insulin which controls
the level of glucose or sugar in the blood.
The gene is responsible why you are different from
everyone else alive today and even among those
who lived in the past.
But it is also the same gene responsible why you
shares some features of your family members.
13. Genes store the information needed to make the
necessary proteins that will eventually lead to
specific traits.
It determines how you will look outside and how
your body will work inside.
The DNA are tightly coiled around special proteins
called HISTONES and make up the chromosomes.
Chromosomes are found inside the nucleus of the
cell.
14. Chromosomes replicate before a cell divides to
make sure that each daughter cell will contain the
complete set of chromosomes.
15. From Haploid to Diploid
All living things have the ability to reproduce
in order to perpetuate their own kind.
But multi cellular organisms like human
being go through a complex series of events
in some cells of their body, specially in their
sex cells or gametes, to maintain the
chromosomes number of a particular species.
16. Chromosomes Number of Some
Organisms
Organisms Diploid
Number (2N)
Haploid (N)
Human 46 23
Mosquito 6 3
Housefly 12 6
Cat 38 19
Chimpanzee 48 24
Dog 78 39
Onion 16 8
Rice 24 12
Potato 48 24
Cotton 52 26
17. The process by which sex cells divide and shuffle
their genetic materials is called MEIOSIS.
Meiosis takes place in the sperm and egg cell of
animal and in the anther and ovaries of plants.
It results in daughter cells which posses half the
number of chromosomes of the parent cell.
This is necessary so that when sex cells unite
during the fertilization, the original number of
chromosomes is maintained.
18. Human being have 23 chromosomes in their
GAMETES, and therefore contain only half of the
complete set of chromosomes.
These sex cells are said to be HAPLOID. It is
represented by letter n
19. During fertilization, the sperm carries only half the
number of chromosomes (haploid) and unites with
the egg cell which is also haploid.
Both father and mother contribute a copy of each
gene to the resulting offspring.
20. Two sets of
chromosomes from
both parents now
results in 46
chromosomes in the
developing embryo.
The resulting zygote
from the union of the
egg and sperm now
have a complete set of
chromosomes and is
said to be diploid,
represented by 2n.
21. All cells of our body with the exception of the sperm cells contain
the complete set of chromosomes.
The first 22 pairs are body chromosomes or autosomes and the 23
pair make up the sex chromosomes.
22. The sex chromosomes determine the sex of an
individual.
Egg always carry an X
sex chromosomes
while the sperm may
carry either X or a Y
chromosomes.
The egg and the sperm
carry one member of
the sex chromosome
pair.
23. If an X bearing sperm
fertilizes an egg, the
resulting offspring is a
female (XX)
But if a Y-bearing sperm
fertilizes and egg, the
resulting offspring is a
male (XY)
24. In short, the 44 chromosomes are autosomes and the 45th
and 46th chromosomes are sex chromosomes.
In human,
chromosomes
number 1 is
the biggest
containing
8,000 genes
and
chromosomes
21 is the
smallest with
300 genes.
25. Variation and Inherited Human
Traits
The combination of the sex cells during
fertilization results in VARIATION in the
offspring.
Several factors influence this variation which
actually happens during the meiotic process.
CROSSING OVER during the prophase stage
of meiosis.
26. Crossing over allows
the exchange of a part
of a chromosomes
with another part
from its homologous
or identical
chromosomes.
It occurs at a number
of different points on
the same
chromosomes, this
leads to greater
variation.
27. MUTATION or the permanent change of DNA
sequence can also result in variation.
These changes may be brought about by
environmental factors such as:
a) exposure to ultraviolet or nuclear radiation
b) exposure to chemicals
It may also happen during the time when a cell
copies its DNA before it divides.
If the mutation takes place in the gametes, they can
readily passed on to the offspring.
28. Most genes have two or more variations called
ALLELES.
For instance, the two alleles for hairline shape are
straight and heart-shape hairline.
A child may inherit the same allele or two different
alleles from his/her parents.
Two different alleles will interact in specific ways
to cause a trait to be expressed.
29. Other inherited traits include:
a) Free and attached airlobe
b) Straight or the bent thumb
c) Tongue rolling
d) Color of eyes
e) Shape of lips
f) Color of hair
g) Blood type
h) Diabetes
i) Texture of the hair
30. The actual set of genes carried by an organism is its
genotype and expression of manifestation of an
organism, the gene type is called PHENOTYPE.
An individual is said to be HOMOZYGOUS if the
alleles for a traits are identical or the same.
A person with two alleles for freckles is
homozygous for that particular trait.
Similarly, if a person also has two alleles for no
freckles, then he or she is homozygous as well.
31. An individual is said to be
HETEROZYGOUS when the two inherited
alleles are different for a particular gene.
In this case, an individual who possesses one
allele for freckles and one allele for no
freckles is heterozygous.
Alleles interact in a dominant or recessive
manner.
32. A DOMINANT ALLELE expressed itself and
masks the effect of the allele for the same traits.
For example, a person has an allele for free or
hanging earlobes and one allele for attached
earlobe, yet what was expressed in his physical
appearance is free earlobes.
33. A RECESSIVE ALLELE on one hand is one
expressed in the presence of the other allele.
Recessive allele can only be expressed when the
organism is homozygous for the recessive alleles.
A trait is symbolized by one letter.
for example: earlobe may be represented by
the letter E
Its alleles may be written in the following
manner: EE, Ee, ee.
34. Its alleles may be written in the following manner:
EE, Ee, ee.
Since free earlobes is dominant it is represented by
a capital letter E, attached earlobe is recessive thus
it is written as a small letter e.
a) homozygous dominant genotype EE = free
b) heterozygous Ee = free
c) homozygous recessive ee = attached
35.
36. Traits and Expression in Human
Traits Expression
1. Shape of face
Oval : dominant,
Square : recessive
2. Cleft in chin
No cleft: dominant
Cleft : recessive
43. Traits Expression
15. Hitch hiker
thumb
Straight thumb : dominant
Hitch-hiker thumb: recessive
16. Hair on Back
hands
No Hair: dominant
Hair :recessive
44. Gene Mutation
Sometimes, an organism may appear with a
genetic trait totally unlike anything that is
seen in otjer members of the species.
This total unlikeness is a physical
manifestation of changes at the biochemical
level which are called MUTATIONS.
45. Mutations may either SOMATIC or GERM
SOMATIC MUTATION occurs in any body cells
except the reproductive cells.
It is not passed on to the offspring and will cease
to exists when the parent or organism dies.
GERM MUTATION occurs in reproductive cells
and is transmitted to offspring.
It may be passed on from one generation to
another.
46. Causes of Mutation
1. High energy radiation
Exposure to different kinds of rays : cosmic
rays, radiation from radioactive elements, X-
ray, gamma rays, beta particles and ultraviolet
rays.
High-energy radiation is one of the most
frequent causes of mutations.
47. 2. Chemical as mutagens (agent of mutation)
among these mutagens are formaldehyde, nitrous
acid, peroxide, mustard gas, marijuana plants
61 cannabinoids with the principal component
delta-9-THC. This component has been traced
as radioactive, and it takes 5 to 8 days for just half
the THC in a single marijuana cigarette to clear
from the body.
constant exposure to THC diminishes the capacity of
individual cells to begin life according to genetic
plan built into cellular molecules.
48. 3. Induced mutations
One form of induced mutation comes from
recombinant DNA experiments.
Here, DNA from one kind of organism is treated with
enzymes to isolate a specific sequence of genes.
These genes are then added to another kind of
organism, and this added DNA recombines (with the
help of some enzymes) with DNA already present in
the recipients organisms.
Consequently, the organism can be considered a
mutant
49. MUTATIONS
Changes which can be
inherited
Changes in
Chromosomes
Cause by
Nature
Changes in
Chromosomes
Changes in
Chromosomes
Genetic Changes
50. NN Non-Mendelian Inheritance
Our modern understanding of how traits may be inherited
through generations comes from the principles proposed by
Gregor Mendel in 1865.
His experiment on Pisum sativum, or pea plants led to the
following principles:
a) Independent assortment – traits are inherited
independent of each other.
b) Dominance- when pure parents with opposite traits are
mated, the first generation shows only one traits
(dominant). The other trait (recessive) is hidden
c) Segregation – when hybrid are crossed, the opposite
traits are separated into different offspring in a ratio of
3:4 (dominant : recessive)
51. However, not all pattern of inheritance obey
the principle of Mendelian genetics. In fact,
many traits we observe are due to a combined
expression of alleles
Non-Mendelian inheritance is a term that refer
to any pattern of inheritance in which traits do
not segregate in accordance with Mendel’s
principle (that is, each parent contributes one
of two possible alleles for a traits)
52. A. INCOMPLETE DOMINANCE and
CODOMINANCE
Incomplete dominance occurs when one allele is
unable to express its full phenotype in a
homozygous individual.
This results to an individual with a phenotype that
is intermediate to homozygous individual.
53. Red Carnation is
dominant over white
carnation.
Following Mendel’s
principle of dominance,
when these traits are
crossed, the dominant
red carnation should
hide the recessive white.
54. Scientists after Mendel
found out differently.
In 1760, Josef Kolreuter
crossed pure red
carnation (RR) and pure
white carnation (WW)
and produced pink
carnation – an
intermediate phenotype
of red and white.
The phenotype of the offspring is a “blend” of the parent’s
phenotype. This is an example of incomplete dominance.
57. Codominance is a situation in which both alleles are equally
strong and both alleles are visible in the hybrid genotype.
An example of codominance is found in chickens.
When a white chicken is cross with black chicken, the result
is not a grey chicken, but a chicken with both black and
white feathers.
58.
59.
60. B. Multiple Alleles
A gene with more than two alleles is said to have multiple
alleles.
Many genes exist in multiple alleles.
A rabbit’s coat, for example has at least four different
alleles
Hair color is determined by a single gene with a series of
alleles, each resulting in different colors like alleles for
black, brown, blond, etc.
61.
62. C. Epistasis
The interaction between two or more genes to
control a single phenotype result in an
inheritance pattern called EPISTASIS.
It occurs when the action of one gene is
modified by one or several other genes, which
are sometimes called MODIFIER genes.
A gene can either mask or modify the
phenotype controlled by the other gene.
63. Masking epistasis occurs when a gene at one
locus masks the expression of a gene at the
second locus so its phenotype is not
expressed.
Modifying epistasis occurs when a gene at one
locus modifies or change the expression of the
phenotype of a gene at the second locus
The gene that does masking / modifying is
referred to as epistatic, while the gene that is
masked / modified is referred to as hypostatic.
64. Labrador’s coat
color vary from
yellow to black
and is controlled by
two dominant
alleles, one for the
presence of dark
pigment (allele E)
and another for the
degree of
pigmentation
(allele B)
The coat of Labrador retrievers show masking epistasis.
65. Chaff Colour in Oat. In Oat, the chaff can have three colours - black, grey and white.
Black colour (B-) is dominant over all others. In its absence grey colour (bbG-) is
dominant over white (bbgg). The dominant gene of black colour (B) is epistatic over the
alleles for grey and white chaff colour (G-and gg). When a pure black chaff producing
plant (BBGG) is crossed with a pure white chaff producing plant (bbgg) the hybrids of
F1 generation plants have black chaff (BbGg). On self breeding the resultant plants of
F2 generation have three types of chaff in the ratio of 12 black : 3 grey : 1 white.
66. Fruit Color in Cucurbita pepo.
In Summer Squash or Cucurbita pepo, there are three types of fruit color-
yellow, green and white.
White color is dominant over other colors
while yellow is dominant over green.
Yellow color is formed only when the dominant epistatic gene is represented by its
recessive allele (w). When the hypostatic gene is also recessive (y), the color of the fruit
is green.
67.
68.
69.
70.
71. D. Sex-linked Traits
After Mendel’s garden peas, an American geneticist
Thomas Hunt Morgan studied genetic variations in
drosophila melanogaster (fruit fly).
In 1910, while examining a large number of drosophila,
Morgan found one that had white eyes instead of the normal
red ones; the fly was a male.
72. Morgan had the white-eyed male mate with a re-eyed
female.
All of the offspring in the first generation had red eye.
73. He then mated flies from this generation. As a result, three-
fourths of the second generation offspring had red eyes and
one-fourth had white eyes.
The results seemingly
conformed with the
results Mendel
observed in garden
peas.
However, there was
one striking
difference, that is, all
of the white-eyed flies
were males.
74.
75. Legend
W : Dominant gene for red eyes
XW Xw Female, pure red eyed
XW Xo Male, red eyed (W cover O)
White-eyed male X Red-eyed female (pure)
XW Xo XW Xw
FEMALE
MALE
XW
Xw
XW
Xo
XW XW
XW Xw
Xw X0
Xw X0
Female, red Female, red
Male, red Male, red
Resulting F1
Genotype:
all female are carriers of
white-eyes recessive gene
Phenotype:
All males are normal; red-
eyed
All females appear red-
eyed because W is
dominant.
76. Legend
w : Recessive gene for white eyes
XW Xw Female, hybrid, red eyed (W dominant
Xw Xo Male, white eyed (O cannot cover w)
Red-eyed male X Red-eyed female (hybrid)
Xw Xo XW Xw
FEMALE
MALE
XW
Xw
Xw
Xo
XW Xw
Xw Xw
XW X0
Xw X0
Female, red Female, red
Male, red Male, red
Resulting F1
Genotype:
One-half of the females
are normal, pure red-eyed
One-half of the females
appear red but are carriers
Phenotype:
One-half of the males are
normal; red eyed