Download Polygenic Inheritance

Polygenic Inheritance
–Occurs when a group of _________________ acts together to produce a trait
–The effects of many alleles produce a wide variety of ____________________
–It may be hard to classify all the _________________ of eye color
–Two gene pairs on chromosome pair ____, and one occurs on pair _____ control
eye color. There are thought to be more
–_______________ is dominant over blue in eye color.
Human Genes and Mutations
–Not all mutations are ____________, they might be helpful or have no effect on an
organism
–Chromosome Disorders
–Mistakes that result in a new organism with ____________________
chromosomes
–Is usually ____________
–1. Down Syndrome -Extra 21 Chromosome
–________________ copies of the 21 Chromosomes results in Down Syndrome
–
–Exhibit learning ______________________
–
–Can lead a normal life
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2. Trisomy 18 – Extra 18 Chromosome
•These physical findings if Trisomy 18
•They include: prominence to the back part of the head,
–
–
–
–clenched fist with index finger overlapping the third and 5th finger overlapping
the 4th, small fingernails,
–underdeveloped or altered_____________
–short sternum (_________________)
–club feet and redundant skin at the back of the neck.
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3. Klinefelters
–_________males are almost always sterile,
– some degree of _____________impairment may be present.
–a lanky, youthful build and facial appearance,
–risk of breast cancer, pulmonary disease, varicose veins, and osteoporosis, risks
shared with women.
–. Occurs ____________to ____________males
–________________ characteristics:
–tendency to grow less body ________,
–small testicular (testes) size,
–long _____________________,
–narrow shoulders,
–poor _________ growth,
–______________ Development
–and narrow shoulders.
4. Turners Syndrome – Missing Y chromosome
•Identifying features of the condition
– ________________ 100%
–Ovarian failure 90%
– Puffy ___________________80%
– Broad _______________80%
–Low posterior hairline 80%
–Unusual shape and rotation of ___________ 80%
–Small lower jaw 70%
–Arms turned out slightly at _____________ 70%
– Soft upturned nails 70%
– _______________50%
–Cardiac anomalies 50%
– ____________________50%
– Narrow,high-arched palate 40%
Recessive Genetic Disorders
–Genetic Disorders that are caused by _________________ genes
–Such disorders occur when both parents are __________________
–Heterozygous parents show no ________________________
–Child gets disorder when each _______________ passes a recessive alleles to offspring
–1. Cystic Fibrosis
–Homozygous recessive disorder
–Most common _____________ disorder that can lead to death in Caucasian Americans
–Thick _______________ is produced in the lungs instead of a thin fluid
–Makes it much harder to _____________
–Leads to respiratory _______________
–2. phenylketonuria (PKU)
–3. sickle cell anaemia
•Complications
include:
–pain episodes
from the sickle cells blocking blood flow and early breaking apart
–
–increased
infections
________________
–bone damage
–yellow eyes or ______________
–early gallstones
–lung _________________
–________________damage and loss of body water in urine
–blood blockage in the ______________ or liver
–eye damage
–low red blood cell counts (_________________)
–delayed growth
–leg
Sex Determination
–Females – Pair of _______ Chromosomes and produces eggs with one X in
–Males 23rd pair of chromosomes are an ___________
–Males produce sperm that have either an ____ or a _____
Sex linked Disorders
•Some inherited conditions are linked with the _______________ chromosome
•A male always receives his X chromosome from his __________________.
• As a result, any genes located solely on the _______________________will be
inherited by the son from his mother.
• In contrast, since females receive an X chromosome from both parents, females inherit
X linked genes from ___________________________
Examples
–1. Color Blindness
–Recessive on X Chromosome
–Males with the allele on the X chromosome is Color blind because they only carry
_____ X chromosome
–Females, ______________________need to have the color blind allele to be color blind
–Females with one are called _________________
–2. Hemophilia
–A person with hemophilia has blood that ________________
–Normal clotting factors is symbolized as _________
–Symbol for hemophilia is __________
•3. Colors of a Calico Cat are recessive and carried on the X chromosome
Pedigree
–Pedigree is a _________________ for following a trait through a generation of a family
–Males represented by _____________
–Females represented by _______________
–Completely _________________ in shape represents that the trait is seen in that person
–Half colored shape represents that the person is a _______________
–Geneticist use pedigrees to ______________ the probability that a baby will be born
with a specific trait.
–Pedigrees also important in breeding _________________________
–Organisms such a livestock and plant crops are bred to increase their
_______________________________________________