Chapter 3: principles of genetics

who formed the foundational work on genetics?

Gregor Mendel

what did mendel’s experiment show?

how traits are passed from one generation to the next

what did mendel’s P1 generation show?

a dominant yellow seed color and a recessive green seed color

what happened when Mendel crossed yellow and green peas

it produced a full generation of yellow seeds and generations with mostly yellow seeds, showing that the yellow trait is dominant over green

what is mendel’s law of segregation

showing how alleles separate into gametes and recombine in offspring

what is a punnett square

tools used in biotechnology to predict inheritance patterns of traits and genetic disorders

how are punnett squares used in biotechnology

predicting inheritance of trait patterns and genetic disorders.

what is the law of independent assortment

how traits and genes are independently inherited

why is the law of independent assortment important in biotechnology

its used to understand how traits and genes are inherited independently

what is a testcross?

a tool to determine whether an individual showing a dominant trait is homo or hetero- zygous 

what is homozygous

organism w two identical alleles inherited from each parent

what is heterozygous

organism w two different alleles inherited from each parent

why are testcrosses important in biotechnology

they help identify carriers of genetics traits and predicting the inheritance of disease

what is incomplete dominance 

how traits blend when no allele is completely dominant 

what does incomplete dominance show in biotechnology 

how genetic variation creates intermediate phenotypes 

what is codominance

genetic inheritance of two different alleles that are fully expressed in the individual 

what is an example of a trait determined by codominance

human blood types

why is codominance important in biotechnology

medicine, transfusions, and paternity testing

what is polygenic inheritance

traits form a range or gradient of phenotypes

what is a classic example of polygenic inheritance

skin color, height, and weight 

what type of results does polygenic inheritance produce 

a bell-curve distribution of traits

how is sex determined

the combination of sex chromosomes

why is sex determination important in biotechnology

understanding inheritance, genetic disorders linked to sex chromosomes, and applications in biotechnology like prenatal testing

how are sex linked traits determined

which sperm fertilizes the egg

why are males more likely to express x-linked disorders

because they only have one x chromosome

how do females express sex linked disorders

they have to inherit two copies of the mutated gene

why is it important to understand sex-linked inheritance in biotechnology

genetic engineering, disease diagnosis, and genetic variations 

what are chromosomal alterations

changes in structure or the number of chromosomes

what is deletion

when a segment of the chromosome is lost

what is inversion

when a segment of the chromosome is reversed

what is translocation

when a segment of a chromosome moves to a non-homologous chromosome

what is duplication 

when a segment of the chromosome is repeated 

what is crossing over 

exchange of genetic material between homologous chromosomes during meiosis 

why is crossing over important in science and biotechnology

increases genetic diversity and can be used during genetic mapping and breeding

when does crossing over occur

prophase 1 of meiosis

what is nondisjunction 

failure of chromosomes or sister chromatids to separate properly during cell division 

what is the result of nondisjunction

abnormal number of chromosomes in the cells

what diseases does nondisjunction help explain

down syndrome, turner syndrome, and Klinefelter syndrome

what is downs syndrome

a genetic disorders caused by the presence of all or part of a third copy of chromosome 21 

what is turner syndrome

genetic disorders affecting people with two x chromosomes, usually they have one x chromosomes missing or partially missing 

what is Klinefelter syndrome 

genetic condition affecting male assigned at birth where they have an extra x chromosome