Genetics week 9 Flashcards
Genetic Variation in population: - Hardy Weinberg Principle - Causes of genetic variation
What is the definition of probability
- The probability of times a specific outcome occurs in a series of events
-It ranges from 0 to 1
For independet events do we add or multiply
multiply
For mutually exclusive do you add or multiply
-Add
What is the significance of gene and genotype frequencies
- They describe the porportion of alleles and genotypes in a population
What does the Hardy-Weinburg principle provide?-
- It provides a mathematical relationship between gene frequencies and genotype frequencies in a population
What does they hardy-weinburg assume
-There is random mating
-No evolutionary influences such as selection,mutation or migration
When can all genotypes be directly observed and counted
When they are co dominant
What are the implications of hardy weinburg principle
- Provides a baseline for comparing real populations to see if evolutionary forces are at work
- Deviation suggest processes like selection,Mutation,migration or non-random mating
Name 3 main causes of genetic variation
- Mutations
-Natural selection - Selective advantage of disease mutation
What is the role of natural selection as causing genetic variation
- Acts as the editor of genetic variation:
- It increases frequencies of favorable mutations that improve survival and reproduction
-It decreases the frequencies of favourable mutations that reduce survival and reproduction
What is the definition of natural selection
Natural selection is an evolutionary process where alleles that confer survival or reproductive advantages are postively selected,increasing their frequency
What is genetic drift
- It is a random evolutionary process that causes changes in gene frequencies, particularly in small populations
What effect does gene drift have in small populations
-In small populations, gene frequencies can fluctuate significantly from generation to generation.
What effect does genetic drift have in large populations
- They experience less random fluctiations
What is founder effect?
- It is a specific type if genetic drift where a small population founded by a few individuals experiences large changes in gene frequency
What is the impact of genetic drift on disease alleles
- It can increase or decrease the frequency of genetic disease
What is gene flow
- The exchange of genes between populations through mating reduces genetic differences
What does the selective coefficient (s) represent
- It represents the reduction in reproductive fitness due to a harmful allele
What is the mutation-selection balance
- A balance between new mutations introducing harmful alleles and natural selection removing them
What are the challenges when diagnosing metabolic disorders
-Diagnosing metabolic disorders is difficult, often leading to underestimation of associated morbidity.
What is the inheritance pattern of metabolic disorders
- Most metabolic disorders are autosomal recessive, requiring 2 mutant alleles to manifest symptopms
Metabolic disorders can be classified based on what factors?(4)
- Pathological effects
-Functional protein classes
-Associated cofactors
-Affected pathways
What is the role of enzymes in metabolism
-Enzymes act as catalysts, increasing rate of reactions
Theese reactions are essential for synthesizing, transferring, using, and degrading biomolecules, which are crucial for building and maintaining cells, tissues, and organs
Name the 4 primary biomolecule groups
- Nucleic Acids
-Proteins
-Carbohydrates
-Lipids
Name 3 pathways involved in metabolising biomolecules
- Glycolysis
-Energy production
-Citric Acid cycle
What is the impact of defective pathways
- Can lead to human diseases, affecting various psychological processes
What is Galactosemia
- A common monogenic disorder of carbohydrate metabolism
What is the prevelance of Galactosemia
Affects 1 in 500,000 new borns
What is Galactosemia caused by
- Mutations in the gene coding galactose-1-phosphate uridyl transferase
What is the result of galactose-1-phosphate uridyl transferase deficiency
- Prevents the conversion of galactose into glucose leading to the accumulation of galactose
What do symptoms of Galactosemia include and when do the symptoms appear
-jaundice,poor sucking and if left untreated: sepsis , liver damage and death can occur
- Symptoms appear in the newborn period
What is the diagnois for Galactosemia
-Newborn screening
What are the long term effects of having Galactosemia
- poor growth
-Development delay
-Speech problems
Name the 2 types of fructose metabolism defects
1.Fructosekinase deficiency
2.Hereditary Fructose Intolerance
which types of fructose Metabolism defect is the most common
- Fructosekinase deficiency
What is fructokinase deficiency caused by
- Mutations in the gene coding hepatic fructokinase
- Results in fructose in the urine
What is hereditary fructose intolerance caused by?
-Caused by a deficiency of fructose 1,6 bisphosphate adolase in the liver, kidney cortex and the small intestine
What does Hereditary Fructose intolerance lead to
- Leads go poor feeding,liver and kidney issues and potentially dath when the fructose or sucrose is ingested.
What is the prevelance of Hereditary Fructose Intolerance
- 1 in 20 000 births
What does fructose 1,6 bisphosphate adolase deficinecy cause in realtion to Hereditary Fructose Intolerance
- Causes impaired gluconeogenesis,hypoglycemia
Which type of Fructose Metabolic Defect is asymptomatic
Fructokinase deficiency
What are abnormalites in glucose metabolism a result of
- environmental and gentic factors
Name the 3 disorders of Glucose Metabolism
- Type 1 diabetes mellitus
-Type 2 diabetes mellitus
-Maturity onest diabtes of the young(MODY)
What is Type 1 diabetes Mellitus a result of
And when does it occur
- Reduced or absent plasma insulin
-Usually in childhood
What is type 2 diabetes mellitus characterised by
- insulin resistance
What does MODY stand for as a glucose metabolism disorder
- Maturtity onset diabetets of the young
What helps to explain the pathways involved in glucose metabolism
rare genetic mutations
Name and describe the examples of rare gene mutations that explain the pathways involved in glucose metabolism
describe: - What it causes and associated with
- Insulin receptor gene mutation: causes insulin resistance
-Mitochondrial DNA mutation: associated w hyperglycemia disorders
-
What is Lactose sugar made of?
- Glucose and galactose
What is lactose metabolised ?
- lactas-phlorizin hydrolase
What areas is Lactase persistence prevalent in
- areas with high milk consumption
How does lactase persistence offer a selective advantage
-By allowing adults to use dairy as vitamin D source
What is the name of the disorder for lactose
- Lactase Nonpersistence(Intolerance)
What are the symptoms of Lactas Nonpersistence(Intolerance)
- Nausea,bloating and diarrhea after lactose consumption
How could the lactose content be reduced
- By processing dairy
