BIO 160 Chapter 9 Flashcards
self fertilization
mendel covered flowers with a asmall bag so that no pollen from another plant could reach the carpal
cross-fertilization
fertilization of one plant by pollen from a different plant
purebred organisms
varieties for which self fertilizaion produced offspring all identical to the parent
P generation
parents
F1 generation
kids
F2 generation
when F1s offspring
heredity
transmission of traits from one generation to next
genetics
the scientific study of heredity
character
a hereditable feature like flower color
trait
variant of character
hybrids
offspring of two purebred varieties
monohybrid cross
parents differ in one character
alleles
alternative versions of a gene
homozygous
identical alleles
heterozygous
different alleles
dominant allele
one that determines organisms appearance
heterozygous vs homozygous
Aa vs AA or aa
dominant allele vs recessive allele
dominant shows in either heterzygous or homozygous.. recessive shows only on homo.. masked in hetero
genotype vs phenotype
phenotype- the organisms physical appearance
genotype - the genetic makeup
phenotypic ratio vs genotypic ratio
appearance makeup vs the genetica make
define the law of segregation and how it applies to reproduction
both the parents contribute an allele to make the offsprings’ a pair
define mendel’s law of independent assortment and explain how it applies to a dihybrid cross
one character doesn’t infuence another.. yellow wrinkles, yellow round, green wrinkles, green round
explain how a testcross can be performed to determine an organisms genotype
testcross is mating with a homozygous recessive.. to figure out the parents’s genotype.. wheter het or homozygous
explain how and when the rule of multiplication should be used to determine a probability of an event
probability of event is the product of separate probabilies of independent events
Explain how a pedigree is used to determine how a particular human trait is inherited
pedigree is a family tree that traces the trait
Define a carrier and explein how carriers are revealed in human pedigrees
a carrier has the recessive allele but doesn’t show it.. they can pass the the recessive allele to the offspring
complete dominance vs incomplete dominance vs codominance
Complete Dominance: Where in the dominant gene completely masks the effect of the resesive gen in heterozygous conditions. Ex. Tt or Rr.
Incomplete Dominance: When 2 or more alleles influence a phenotype. Ex. Flowers.
Codominance: When both alleles for a gene are expressed in heterozygous offspring. Ex. Bloodtype.
explain how the environment influences the expression of traits
exercise effects build, height is influenced by nutrition and excercise
explain how chromosomes determine the sex of a human
in sperm half have x half have y..offspring sex is determined on whether sperm that fertilizes egg is an X or Y
explain why sex-linked diseases are more common in male humans
they get their X chromosome from their mothers
red-green colorblindness vs hemophilia
red green colorblindness is a common sex-linked disorder caused by a malfunction of light sensitive cells in the eyes can see 25 colors mostly males are affected because its on sex chromosome males have 50% chance of colorblindness. hemophilia bleed excessively when injured.hets are affected
law of segregation
when sperm and egg unite at fertilizaion, each contributes its alleles restoring the paired condition in the offspring
punnet square
highlights the possible combinations of gametes
locus
specific location on a gene
dihybrid cross
the mating of parental varieties differing in two characters
law of independent segregation
the inheritance of once character has no effect on the inheritance of another
test cross
a mating between an individual of dominant phenotype but unknown genotype with a homozygous recessive
wild type traits
those seen most often in nature
pedigree
family tree
cystic fibrosis
excessive secretion of thick mucus from lungs pancreas and other organs
inbreeding
mating between close blood relatives
achondroplasia
a form of dwarfism in which head and torso develop normally but arms and legs are short
huntington’s disease
a degeneration of the nervous system that doesn’t begin until middle age
incomplete dominance
the appearance of F1 hybrids falls between the phenotypes of the parents.. red + white = pink
hypercholesterolemia
dangerously high levels of cholesterol in the blood Normal have HH heterozygotes have cholesterol levels that are 2x normal
codominant
that both alleles are expressed in Heterozygous individuals who have type AB blood
pleiotrophy
one gene influences several characters
sickle cell disease
disorder characterized by a diverse set of symptoms. red blood cells produce abnormal hemoglobin proteins
polygenice inheritance
the additive effects of two or more genes on a single phenotypic character.. height AABBCC or aabbcc
linked genes
genes that are located close together on a chromosome
