Inheritance and Chromosomes

Flashcards covering key vocabulary terms related to genetics, chromosomes, and inheritance patterns discussed in the lecture notes.

Chromosomes

Linear DNA wrapped around histones with homologous pairs

Mendels Extensions

• sex linked haemophilia

• mitochondrial inheritance

• polygenic

• co dominance

• incomplete penetrance

• multi factorial

Chromatin

DNA wrapped around histones, forming chromosomes that are joined at centromere

Aneuploidy

Abnormal number of chromosomes; too many or too few.

Trisomy

Three copies of one chromosome

18 - edward’s

13 - pataus

21 - downs

Monosomy

One chromosome missing.

Nondisjunction

Failure in chromosome separation during meiosis, resulting in more or less chromosomes in oocytes or sperm.

Mosaicism

Presence of two or more genetically different cell lines in the body.

Klinefelter's Syndrome

XXY; results in taller stature, feminine characteristics, and reduced fertility due to small testes.

Turner Syndrome

XO; results in short stature, webbed neck, and sterility due to undeveloped ovaries.

Recessive Inheritance

Trait expressed in siblings but not parents, often skipping a generation; more common with consanguinity.

Consanguinity

Inheritance more common with recessive traits due to incest

Mitochondrial Inheritance

Inheritance through the egg during fertilization, allowing mtDNA to show maternal relation.

Polygenic Inheritance

not in a typical Mendelian pattern (one gene), involving multiple factors (e.g., height, skin color).

Incomplete Penetrance

Probability that a person carrying a dominant gene will manifest it; can be sex-dependent. Dominant is not always expressed

Triple X

meta females, long limbs and slender, fertile and may have slight learning difficulties

Y - linked

every son of affected father will be affected while daughters will never

e.g azoospermia - inability to produce sperm

Mandibular Progbathism

hasburgs - caused by incest and dominant allele , low drooping lip and jaw

Mendel

1866, plant hybridisation

F1 = 3:1 F2 = 1:2:1

Fleming

discovers chromosomes using red dye in 1878

Boveri and Sutton

1902 - chm theory of inheritance, chm in pairs and separate in meiosis

Morgan

1930

chm carry genes

eye colour of bugs