Heredity and genetics

HEREDITY AND GENETICS

Part 1

By Vijaya Sawant PMP

Oratechsolve Inc

Heredity defines biological transmission of physical and psychological traits from generation to

generation.

The field of biology that studies heredity is called GENETICS.

Traits are transmitted by Chromosomes and Genes.

Life begins as a single cell or

zygote that divides repeatedly.

© Fancy/Veer/Corbis

Genes are segments of strands of deoxyribonucleic acid (DNA).DNA forms a double spiral (HELIX) that looks like a twisting ladder.

Each “rung” on the ladder consist of 4 basic chemicals that are placed in pairs of either: Adenine and Thymine or Cytosine and Guanine

The sequence of the rungs are the individual genetic code that cause the developing organism to grow arms, wings, skin, or scales.

There are TWO types of cell division Mitosis and Meiosis

The Double Helix of DNA

Mitosis

Identical and Fraternal Twins

Monozygotic Dizygotic

Using PDA technique you can select genes like color of eyes, sex

© Fancy/Veer/Corbis

Chromosomal Abnormalities

• Abnormalities in 22nd or 23rd pairs of autosomes.

• Genetic abnormalities are caused by combinations

of genes called Multifactorial problems

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Down Syndrome

It is caused by an extra

chromosome of the 21st

pair resulting in 47

chromosomes.

Children show deficits in

cognitive and motor

development.

Typically die from

cardiovascular arrest in

middle age.

Sex-Linked Chromosomal Abnormalities

Turner Syndrome (X)

1 girl in 2,500 has syndrome.

Female is shorter than average and infertile.

Cognitive deficits problems with visual-

spatial skills, mathematics and

nonverbal memory.

(XYY) Syndrome

Rare abnormality in men.

Occurs in 1 in 1,000 males.

Active in sex and sport, learning difficulties, delayed speech and difficult time with communicating.

Klinefelter Syndrome (XXY)

1 male in 500 has syndrome

Produces less testosterone

Usually have enlarged breasts

Mild retarded particularly language, Infertile

Triple X Syndrome (XXX)

1 girl in 1,000 has syndrome.

Normal in appearance

Lower than average language skills, poor memory for recent

eventsDevelopment of external

sex organ normal

Genetic Abnormalities

• A number of disorders attributed to genes:

– Phenylketonuria (PKU)

– Huntington’s Disease

– Sickle-Cell Anemia

– Tay-Sachs Disease

– Cystic Fibrosis

– Sex-Linked Genetic Abnormalities

– Blood Linked Genetic Abnormalities

Phenylketonuria (PKU)Enzyme disorder transmitted by a recessive gene affecting 1 child in 8,000.

Cannot metabolize an amino acid called

phenylalanine;

Builds up in body and impairs functioning of the

central nervous system (CNS);

Results are mental retardation, psychological

disorders, physical problems

No cure, but PKU can be detected in new born children through blood or urine analysis; if identified placed on diets low in phenylalanine within three weeks of

birth and develop normally

Huntington’s Disease

Fatal, progressive degenerative disorder

Uncontrollable muscle movements, loss of

intellectual functioning and personality change

No Cure; Half of offspring will have disorder

Sickle-Cell Anemia

Common among African American

Red blood cells take a shape of sickle

obstructing blood and oxygen supply

Impair cognitive and academic functions,

organs failure

Cystic Fibrosis

Caused by recessive gene

Fatal hereditary disease among

European Americans

30,000 Americans have disorder, 10 million more are carriers (1 in 31

people)

Duchenne Muscular Dystrophy

Duchenne Muscular Dystrophy symptoms

Genetic Bleeding Disorder

AbnormalitiesHemophilia

1 in every 4,400 live male birth in the United States.

Caused by shortage of certain clotting factors in

blood.

Spontaneous bleedingProlonged bleeding

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“Test-tube” babies are grown in a laboratory dish throughout their 9

month gestation period.

Misconception

Oratechsolve Inc.Promoter of Maternal and Neonatal Health Literacy

Email: [email protected]