3.4 Inheritance Flashcards
What experiments led Mendel to discover the principles of inheritance?
Mendel’s experiments with pea plants, crossing large numbers, revealed inheritance principles.
What are Mendel’s principles of inheritance?
Mendel outlined segregation, independent assortment, and dominance.
Why do gametes contain only one allele of each gene?
Gametes are haploid, carrying one allele per gene due to meiosis.
How do alleles of each gene separate during meiosis?
Alleles segregate into different haploid daughter nuclei during meiosis.
What results from the fusion of gametes in terms of zygote’s alleles?
Fusion results in diploid zygotes with two alleles of each gene, same or different.
How do dominant and co-dominant alleles affect phenotype?
Dominant alleles mask recessive ones; co-dominant alleles have joint effects.
How do you construct Punnett grids for monohybrid crosses?
Punnett grids predict genetic crosses’ outcomes by aligning parents’ alleles.
Describe the inheritance of ABO blood groups.
ABO inheritance involves co-dominant (IA, IB) and recessive (i) alleles.
What genetic basis underlies many human diseases?
Diseases often stem from recessive autosomal alleles; some involve dominant/co-dominant alleles.
Explain the inheritance of sex-linked diseases.
Sex-linked diseases result from alleles on sex chromosomes, affecting males and females differently.
How is the inheritance pattern different for sex-linked genes?
Sex-linked inheritance varies with the gene’s sex chromosome location, affecting males and females differently.
State the mutation rate increase due to radiation and chemicals.
Radiation and chemicals can significantly elevate mutation rates, leading to diseases and cancer.
Outline the consequences of radiation exposure in Hiroshima and Chernobyl.
Radiation caused genetic diseases, cancer, and acute radiation syndrome in affected populations.
How do actual genetic cross outcomes compare to predicted ones?
Actual outcomes may differ from predictions due to random genetic events; large sample sizes reduce this discrepancy.
What are the principles of inheritance outlined by Mendel?
Mendel’s principles include segregation, independent assortment, and dominance in heredity.
What role does meiosis play in genetic diversity?
Meiosis results in haploid gametes with one allele of each gene, leading to genetic diversity.
How does the fusion of gametes form zygotes?
Gametes’ fusion forms diploid zygotes, combining two alleles of each gene from each parent.
Describe the genetic basis for cystic fibrosis.
Cystic fibrosis is caused by recessive alleles of the CFTR gene on chromosome 7.
Explain the genetic mechanism behind Huntington’s disease.
Huntington’s disease results from a dominant allele of the HTT gene on chromosome 4.
How are red-green colour blindness and hemophilia inherited?
Both disorders are X-linked, with colour blindness being recessive and hemophilia affecting mostly males.
What does analyzing pedigree charts reveal about genetic diseases?
Pedigree charts help deduce inheritance patterns, distinguishing between dominant, recessive, and sex-linked traits.
How do mutations lead to genetic diseases and cancer?
Mutations, often caused by radiation and chemicals, can alter DNA, leading to diseases and cancers.
Discuss the impact of the Hiroshima bombing and Chernobyl accident on human genetics.
Both events led to increased radiation exposure, causing mutations, genetic diseases, and cancers in affected populations.
How does the actual outcome of genetic crosses compare to predicted outcomes?
Actual outcomes may vary due to random genetic variations; large sample sizes can help align predictions with reality.
Why are dominant alleles able to mask recessive alleles?
Dominant alleles express their trait even when paired with a different allele, masking recessive alleles’ effects unless in a homozygous recessive pair.
How do Punnett grids help predict genetic cross outcomes?
Punnett grids visually represent possible genetic combinations from parents, predicting offspring’s phenotypes.
What illustrates the importance of understanding blood group inheritance for transfusions?
Knowing ABO blood group inheritance is crucial for safe blood transfusions, avoiding immune reactions.
