40. Inheritance - basic of Mendelian genetics. Main types of inheritance. Multiple alleles and sex-linked traits.

Question 1

Gene:

allele: alternative form of the gene phenotype:

genotype:

heterozygous:

homozygous:

Answer 1

Gene:

allele: alternative form of the gene phenotype:

genotype:

heterozygous:

homozygous:

Question 2

Law of dominance Law of segregation

Law of Independent assortment: alleles for different traits are distributed independently

Answer 2

Law of dominance Law of segregation

Law of Independent assortment: alleles for different traits are distributed independently

Question 3

Inheritance:

Monogenic - trait is determined by the expression of a signal gene Polygenic - trait is produced from accumulative effects of many genes Autosomal - dominant or recessive

Sex linked - Y linked or X linked

Answer 3

Inheritance:

Monogenic - trait is determined by the expression of a signal gene Polygenic - trait is produced from accumulative effects of many genes Autosomal - dominant or recessive

Sex linked - Y linked or X linked

Question 4

Deviations from Mendals laws:

1. Linked genes
2. interactions between alleles of a gene
   - incomplete dominance (some flowers)
   - codominance (blood groups)
   - overdominance (Aa is the strong genotype, not AA)
3. Interactions between alleles of different genes
   Epistasis: one gene suppresses another one (hypostatic gene, epistatic gene) Positional effect of the gene

Polimery effect (the more alleles the stronger) Complementary: one gene influences the trait of the other

Answer 4

Deviations from Mendals laws:

1. Linked genes
2. interactions between alleles of a gene
   - incomplete dominance (some flowers)
   - codominance (blood groups)
   - overdominance (Aa is the strong genotype, not AA)
3. Interactions between alleles of different genes
   Epistasis: one gene suppresses another one (hypostatic gene, epistatic gene) Positional effect of the gene

Polimery effect (the more alleles the stronger) Complementary: one gene influences the trait of the other

Question 5

4. Pleiotropy: one gene gives rise to multiple traits e.g. phenylketonuria
5. variability of the genetic effect

Penetrance - amount of people with active gene expressivity - severity of the genes activeness
6. inheritance related, dependance or restricted by sex

7. lethal and sublethal factors
8. false domination - deletion, deficiency, monosomy, haploidity, sex-linked inheritance
9. Phenocopy: environmentally induced phenotype mimicking genotype

Genocopy: two different genotypes, one phenotype 10. Influence of the mitochondrial genes

Answer 5

4. Pleiotropy: one gene gives rise to multiple traits e.g. phenylketonuria
5. variability of the genetic effect

Penetrance - amount of people with active gene expressivity - severity of the genes activeness
6. inheritance related, dependance or restricted by sex

7. lethal and sublethal factors
8. false domination - deletion, deficiency, monosomy, haploidity, sex-linked inheritance
9. Phenocopy: environmentally induced phenotype mimicking genotype

Genocopy: two different genotypes, one phenotype 10. Influence of the mitochondrial genes

Question 6

Multiple allele: set of 3+ alleles, or alternative states of a gene Sex-linked traits - gene carried on sex chromosome
Colour blindness + Haemophilia - X-linked (boys more likely to get it - they only have one X)

Hypertricosis - X linked dominant, males can never be carriers

Answer 6

Multiple allele: set of 3+ alleles, or alternative states of a gene Sex-linked traits - gene carried on sex chromosome
Colour blindness + Haemophilia - X-linked (boys more likely to get it - they only have one X)

Hypertricosis - X linked dominant, males can never be carriers