Chapter 3 Flashcards
What is genetics, and how many pairs of chromosomes do humans have?
Genetics is the biological study of heredity and chromosomes, and humans have 23 pairs of chromosomes (46 total)
What is Down syndrome, and which chromosome is affected?
Down syndrome, also known as Trisomy 21, occurs when chromosome 21 has an extra or partial extra copy, leading to distinct facial features and other health issues.
What is Turner syndrome, and whom does it affect?
Turner syndrome is the absence of a full second sex chromosome and only affects genetic females, leading to physical differences and potential cognitive impairments.
What is Tay-Sachs disease, and how is it inherited?
Tay-Sachs disease is caused by the lack of a protein enzyme to clean fat and plaque on the brain and is inherited when both parents are unaffected carriers.
What is muscular dystrophy (Duchenne), and what are its effects?
Muscular dystrophy (Duchenne) is a sex-linked genetic abnormality resulting in rapid muscle dystrophy, loss of mobility, and other health complications.
Describe the difference between meiosis and mitosis.
Meiosis is the creation of sex cells (gametes) with 23 chromosomes each, while mitosis is the propagation of cells through cell division.
What are monozygotic and dizygotic twins?
Monozygotic twins (identical twins) come from a single zygote splitting, while dizygotic twins (fraternal twins) come from two separate fertilized eggs.
Define genotype and phenotype.
Genotype is the combination of parents’ alleles for a gene, while phenotype is the sum of genotype and environment, representing observable traits.
What are simple traits, intermediate traits, and polygenetic traits?
Simple traits are one or the other; intermediate traits are a blend of traits; and polygenetic traits involve many genes contributing to a trait, making prediction difficult.
Explain dynamic systems theory and reaction range.
Dynamic systems theory examines how complex systems change over time. Reaction range is the spectrum of phenotypic possibilities influenced by gene-environment interactions.
What is epigenetics, and how can it be influenced by lifestyle choices?
Epigenetics involves changes in gene expression influenced by lifestyle choices such as smoking and chronic stress, which can affect multiple generations.
