KELAINAN MENURUN PADA AUTOSOM

Summary

This educational video covers human genetic inheritance patterns, focusing on autosomal genetic disorders. The speaker explains various conditions, including albinism, brachydactyly, cataracts, thalassemia, and mental disorders, describing their genetic causes and inheritance. Detailed examples show how to calculate the likelihood of these disorders in offspring using genetic symbols and Punnett squares. The video also touches on the determination of blood groups and sex. The content is designed to help students understand basic concepts of genetics and hereditary conditions, with clear explanations and examples for each topic.

Takeaways

• 😀 Autosomal inheritance refers to genetic disorders caused by genes located on non-sex chromosomes, which are inherited according to Mendelian principles.
• 😀 Albinism is a genetic disorder where individuals lack the ability to produce melanin, resulting in pale skin, and is inherited as a recessive trait.
• 😀 Brachydactyly is a genetic condition characterized by short fingers and toes, and it follows a dominant inheritance pattern, where one dominant allele can cause the condition.
• 😀 Cataracts, a condition that leads to clouding of the eye's lens, impairing vision, are inherited as an autosomal dominant trait.
• 😀 Thalassemia is a blood disorder affecting red blood cells, leading to oxygen supply issues, and can be inherited as a recessive condition (thalassemia minor and major).
• 😀 Mental disorders can also be inherited, and one example in the script is a condition caused by an amino acid buildup in the blood, which disrupts the nervous system.
• 😀 Inheritance of genetic disorders can be understood through Punnett squares, which help predict the probability of offspring inheriting a specific genetic trait.
• 😀 Recessive genetic conditions require both parents to pass on a copy of the mutated gene for the child to express the disorder.
• 😀 Dominant genetic conditions only require one copy of the mutated gene to express the condition, which can be inherited from either parent.
• 😀 The script highlights various examples of genetic inheritance and provides detailed methods for calculating the probability of inheritance using genetic symbols and Punnett squares.

Q & A

What is albinism and how is it inherited?

Albinism is a genetic condition caused by the inability of the body to produce melanin, leading to white skin and light hair. It is inherited in a recessive manner, meaning both parents must pass on the albino gene (represented by 'a') for the child to develop the condition. The genotype for an albino individual is 'a small a small'.

How can you calculate the probability of a child inheriting albinism?

To calculate the probability of a child inheriting albinism, a Punnett square is used. For example, if a heterozygous father (Aa) marries an albino woman (aa), there is a 50% chance that the child will inherit albinism, as the possible genotypes are 50% heterozygous carriers (Aa) and 50% albino (aa).

What is brachydactyly and what inheritance pattern does it follow?

Brachydactyly is a genetic condition causing shortened fingers and toes. It follows a dominant inheritance pattern, meaning only one copy of the dominant allele (B) is required to express the condition. The genotype for an individual with brachydactyly is 'B' for the dominant allele and 'b' for the normal allele.

If two individuals with brachydactyly marry, what is the likelihood their child will have the condition?

If both parents are heterozygous for brachydactyly (Bb), the probability of their child inheriting the condition can be determined using a Punnett square. The possible genotypes would be 25% 'BB' (fatal), 50% 'Bb' (affected), and 25% 'bb' (normal). Hence, there is a 50% chance the child will have brachydactyly.

What is the cause of cataracts and how is it inherited?

Cataracts are caused by clouding of the eye's lens, leading to blurred vision. Cataracts are inherited as a dominant trait, meaning only one copy of the dominant allele (C) is needed to express the condition. The genotype for cataracts is 'C' for the dominant allele and 'c' for the recessive normal allele.

How would you calculate the likelihood of a child inheriting cataracts from a heterozygous parent?

If one parent is heterozygous for cataracts (Cc) and the other parent is normal (cc), the likelihood of their child inheriting cataracts can be calculated using a Punnett square. The possible genotypes would be 50% 'Cc' (affected) and 50% 'cc' (normal), so there is a 50% chance the child will inherit cataracts.

What is thalassemia and how is it inherited?

Thalassemia is a blood disorder caused by abnormal red blood cell shapes, leading to oxygen supply issues. Thalassemia can be classified as 'minor' (heterozygous) or 'major' (homozygous dominant). The inheritance follows a recessive pattern, with 'T' for thalassemia and 't' for normal red blood cells.

If a thalassemia minor individual marries a normal person, what is the chance their child will be affected?

If a thalassemia minor individual (Tt) marries a normal individual (tt), the probability of the child inheriting thalassemia can be calculated using a Punnett square. The possible genotypes would be 50% 'Tt' (thalassemia minor) and 50% 'tt' (normal), so there is a 50% chance the child will inherit thalassemia minor.

What causes mental disorders like phenylketonuria (PKU), and how is it inherited?

Phenylketonuria (PKU) is a metabolic disorder where high levels of phenylalanine build up in the blood, affecting the nervous system. It is inherited in a recessive manner, with 'f' representing the defective allele and 'F' representing the normal allele. A person with two 'f' alleles will express PKU.

If a heterozygous man with a mental disorder (PKU) marries a woman with the disorder, what is the chance their child will inherit PKU?

If a heterozygous man (Ff) with PKU marries a woman with the disorder (ff), the chance their child will inherit PKU can be calculated using a Punnett square. The possible genotypes are 50% 'Ff' (carrier) and 50% 'ff' (affected), so there is a 50% chance the child will inherit PKU.