Genetics of inheritance Flashcards
Distinguish among genome, gene, and chromosome
Genome: complete set of an organisms DNA that contains all instructions needed for organism
Gene: Specific segments of DNA that carry instructions for building proteins, functional units of heredity
-Located on chromosomes
Chromosomes: Structures containing DNA and proteins, organized form of DNA
-Contain many genes, 46 chromosomes/ 23 pairs
Explain how the environment influences how genes are expressed.
Through various mechanisms like epigenetics
-Diet, stress, toxins modify gene activity without altering diet sequence itself
-Influences production of proteins, and risks of developing diseases
Describe a karyotype, and explain what it represents.
A visual representation of an individuals chromosomes, organized by size and shape used to identify chromosomal abnormalities
-Represents complete set of chromosomes including the number, structure and arrangement
-Karyotype help diagnose abnormalities prenatal, cancer
Explain the basis of multiple alleles of a gene.
Arise from mutations in the gene DNA sequence
-Resulting in different versions(alleles) that exist within a population
Distinguish between autosome and sex chromosomes; heterozygous and homozygous; genotype and phenotype; dominant and recessive; mutant and wild type; incomplete dominance and codominance.
Autosomes: #’d chromosomes
Sex chromosomes determine sex
Heterozygous:different alleles
Homozygous: Same alleles
Genotype: Specific alleles for particular trait
Phenotype: Observable traits that result from genotype and environment
Incomplete dominance: RR+WW=RW
Codominance: AB blood type, combination
Distinguish between autosomal recessive and autosomal dominant inheritance.
Autosomal dominant requires only one altered gene copy for a trait to appear
(Marfan syndrome) 50 % of inheriting
Autosomal recessive requires two altered copies (cystic fibrosis) 25% of two copies
Explain how and why the same genotype can have different phenotypes among individuals.
Environmental factors, stochastic developmental events, epigenetic modifications that influence gene expression
Describe and give 3 examples of how traits may be determined by genes and the environment.
Penetrance,Expressivity, and Pleiotropy
Height, skin color, intelligence
Describe how and when sex is determined.
Sex is determined at fertilization with a combination of sex chromosomes inherited from parents detecting sex of offspring
Explain how X-linked inheritance differs from inheritance of autosomal traits, and why the inheritance pattern of X-linked traits differs in males and females.
Makes only have one X chromosome while females have two
Explain why Y-linked traits are passed only from fathers to sons.
The Y chromosome which carries the traits is only passed down from father to son as the father is the one that carrie’s the Y chromosome
Discuss factors that affect how phenotypes may differ between the sexes.
Describe three ways that chromosomes can be abnormal.
Numerical Abnormalities
-Structural Abnormalities( deletions and duplications)
-Mosaicism: two or more different cell populations with different chromosome complements
Explain how prenatal tests provide information about chromosomes.
Analyze fetal DNA to assess ricks of chromosomal abnormalities like down syndrome
Define euploid, anueploid and polyploidy and state whether trisomy 21 Down syndrome is euploid, aneuploid, or polyploidy.
Euploid is normal completely set of chromosomes
Aneuploid is abnormal # of chromosomes (extra or missing)
Polyploidy: Multiple sets of chromosomes
Down syndrome 21 is Aneuploidy
