Gregor Mendel conducted experiments with pea plants to study inheritance of traits. He found that traits are inherited in discrete units (genes) and that some traits (dominant) mask the expression of others (recessive). Through his laws of segregation and independent assortment, he showed that genes separate and assort independently during gamete formation. This allows for prediction of phenotypic ratios in offspring using a Punnett square. Mendel's work formed the foundation of classical genetics and heredity.
1. The document discusses genes and chromosomes, including the chromosome theory of inheritance proposed by Walter Sutton. It describes the structure of DNA and RNA, as well as DNA replication, transcription, and translation.
2. Key experiments are summarized, such as those determining that DNA is the genetic material and the discovery of the DNA double helix structure. The genetic code and how mutations can occur are also covered.
3. Various genetic disorders are listed that result from mutations, including Down syndrome, Turner syndrome, and Klinefelter syndrome. The document concludes with a brief discussion of polyploidy.
Gregor Mendel conducted experiments with pea plants to study inheritance of traits. He found that traits are inherited in discrete units (genes) and that some traits (dominant) mask the expression of others (recessive). Through his laws of segregation and independent assortment, he showed that genes separate and assort independently during gamete formation. This allows for prediction of phenotypic ratios in offspring using a Punnett square. Mendel's work formed the foundation of classical genetics and heredity.
1. The document discusses genes and chromosomes, including the chromosome theory of inheritance proposed by Walter Sutton. It describes the structure of DNA and RNA, as well as DNA replication, transcription, and translation.
2. Key experiments are summarized, such as those determining that DNA is the genetic material and the discovery of the DNA double helix structure. The genetic code and how mutations can occur are also covered.
3. Various genetic disorders are listed that result from mutations, including Down syndrome, Turner syndrome, and Klinefelter syndrome. The document concludes with a brief discussion of polyploidy.
Enzymes are highly specific and catalyze reactions by lowering the activation energy, not by supplying energy directly. Using heat would not selectively catalyze the desired biochemical reactions and could damage cellular components.
28. Technology is providing new tools for genetic testing
and counseling
ความก้ าวหน้ าทางเทคโนโลยีเอือประโยชน์ ในการตรวจหา
้
ความผิดปกติทางพันธุกรรมและการให้ คาปรึกษา
35. Morgan traced a gene to a specific chromosome
Thomas Hunt Morgan เป็ นนัก embryologist ที่มหาวิทยาลัย
โคลัมเบีย ประเทศสหรั ฐอเมริกา ค้ นพบยีนที่อยู่ในโครโมโซม X
(sex linkage) ของแมลงหวี่ (Drosophila melanogaster) โดย
ขณะศึกษาพันธุกรรมของแมลงหวี่ เขาพบแมลงหวี่ตัวผู้ตัวหนึ่ง
มีตาสีขาว (mutant phenotype) ซึ่งแตกต่ างไปจากแมลงหวี่ตาสี
แดงปกติท่ วไป (wild type)
ั
36. Morgan’s first mutant แมลงหวี่ตาสีแดงเป็ นลักษณะปกติ เรียกว่ า
wild type และลักษณะตาสีขาวเป็ น mutant phenotype จากลักษณะนี ้
ที่ทาให้ เขาค้ นพบยีนที่อยู่ในโครโมโซม X
47. Sex chromosomes
The chromosomal basis of sex varies with organism
Some chromosomal systems of sex determination
ระบบการกาหนดเพศแบบต่ างๆในสัตว์ ต่างชนิดกัน
การกาหนดเพศ (sex determination) ในสิ่งมีชีวิตขึนอยู่กับ
้
ชนิดของโครโมโซมเพศ