Chapter 3: Principles of Genetics

Who formed the foundational work on genetics?

gregor mendel

What did mendel’s experiment show?

traits are passed through genes

What did mendel’s P1 generation show?

offspring will only display on parental trait, the dominant one

What happened when Mendel crossed yellow and green peas?

yellow is dominant over green

What is mendel’s law of segregation?

a parent only passes one allele to their offspring

What is a punnett square

a chart that determines possible genotypes

How are punnett squares used in biotechnology?

to predict probability of offspring inheriting specific traits

What is the law of independent assortment?

alleles for different traits are inherited independently of one another

What is the law of independent assortment important in biotechnology?

explains the genetic variation that is essential for selective breeding and genetic engineering

What is a testcross?

when someone with an unknown genotype is crossed with homozygous recessive

What is homozygous?

the same allele

What is heterozygous?

a hybrid allele

Why are test crosses important in biotechnology?

they help figure out what genotype something is

What is incomplete dominance?

when one allele is not completely dominant over the other

How does incomplete dominance show in biotechnology?

utilized to create organisms with intermediate phenotypes

What is codominance?

where both genes are fully expressed equally

What is an example of a trait determined by codominance?

AB blood type

Why is codominance important in biotechnology?

it allows for the creation of genetic markers

What is polygenic inheritance?

the inheritance of a trait governed by more than one genes.

What is a classic example of polygenic inheritance

human height, skin color, eye color

What type of results does polygenic inheritance produce?

continuous variation

How is sex determined?

by the XX or XY chromosomes

Why is sex determination important in biotechnology?

allowing for the separation and selection of males and females based on their desired traits

How are sex linked traits determined?

by genes located on sex chromosomes

hy are males more likely to express X-linked disorders?

they only have one x chromosome

How do females express sex linked disorders?

they are either carriers or have symptoms

Why is it important to understand sex-linked inheritance in biotechnology?

accurately diagnosing and treating genetic disorders

What are chromosomal alterations?

changes in the number or structure of chromosomes,

What is deletion?

when a segment of a chromosome gets deleted

What is inversion?

when a segment of a chromosome gets inverted

What is translocation?

when a segment of a chromosome gets replaces

What is duplication?

When a segment of a chromosome gets duplicated

What is crossing over?

exchange of genetic information between homologous chromosomes

Why is crossing over important in science and biotechnology?

increases genetic diversity

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?

daughter cells with an abnormal number of chromosomes, a condition called aneuploidy

What diseases does nondisjunction help explain?

down syndrome, turner syndrome, klinefelter syndrome.

What is downs syndrome?

extra copy of chromosome 21

What is turner syndrome>

absence or partial deletion of one x chromosome

What is Klinefelter syndrome?

genetic disorder that affects males, caused by an extra X chromosome