chapter 2 mendelian inheritance Flashcards
cross
- breeding between two distinct individuals
- an analysis of their offspring may be conducted to understand how traits are passed from parent to offspring
hybridization
- the breeding of two organisms of the same species with different characteristics
- the phenomenon in which two single stranded DNA molecules from different sources bind to form a hybrid molecules
hybrid
- an offspring obtained from hybridization experiment
- a cell produced from a cell fusion experiment in which the two separate nuclei have fused to make a single nucleus
gamete
a reproductive cell (usually haploid) that can unite another reproductive cell to create a zygote; sperm and egg cells are types of gametes
sperm cell
a male gamete; sperm are small and usually travel relatively far distances to reach the female gamete
pollen grain
the male gametophyte in flowering plants; also called pollen
anther
the structure in flowering plants in which pollen grains form
egg cell
a female gamete that is usually very large and nonmotile; also known as an ovum or egg
ovule
the structure in flowering plants where the female gametophyte (embryo sac) is produced
ovary
- in plants, the structure in which the ovules develop
- in animals, the structure that produces egg cells and female hormones
stigma
the structure in flowering plants on which the pollen lands, stimulating the growth of the pollen tube so that sperm cells can reach the egg cells
self-fertilization
fertilization that involves the union of male and female gametes derived from the same parent
cross-fertilization
a cross in which the male and female gametes come from separate individuals
character
in genetics, a general characteristic such as eye color or height
trait/variant
characteristics of an organism; also specific properties of a character such as tall or blue eyes
true-breeding line (true breeding strain)
a strain of a particular series that continues to produced the same trait after several generations of self fertilization (in plants) or inbreeding
single-factor crosses
a cross in which an experimenter is following the outcome of only a single character
monohybrid
an individual produced from a single factor cross in which the parents had different variants for a single character
empirical approach
a strategy in which experiments are designed to determine quantitative relationships as a way to derive laws that govern biological, chemical, or physical phenomena
parental generation (p gen)
- in a genetic cross, the first generation in the experiment
- in mendel’s studies, the parental generation was true-bleeding with regard to particular traits
F1 generation
offspring produced from a cross of a parental generation
F2 generation
offspring produced from a cross or self-fertilization of the f1 generation
dominant
describes an allele that determines the phenotype in the heterozygous condition; typically denoted with capital letters
recessive
a trait or a gene that is masked by the presence of a dominant trait or gene
particulate theory of inheritance
a theory proposed by mendel; states that traits are inherited as discrete units that remain unchanged as they are passed from parent to offspring
segregate
to place two things in separate locations
gene
- a unit of heredity that may influence the outcome of a trait in an organism
- a segment of DNA that contains the info to make a functional product, either RNA or a polypeptide
allele
an alternative form of a specific gene
mendel’s law of segregation
two copies of a gene segregate (separate) from each other during transmission from parents to offspring
homozygous
describes a diploid individual that has two identical alleles of a particular gene (it TT or tt)
heterozygous
describes a diploid individual that has diff versions of the same gene (ie Tt)
genotype
the genetic composition of an individual, especially in terms of the alleles for particular genes
phenotype
observable traits of an organism
punnett square
diagrammatic method in which gametes that two parents produce are aligned next to a square grid as a way to predict the types of offspring the parents will produce and in what proportions
two factor crosses
a cross in which an experimenter follows the outcome of two different characters
nonparental
refers to a combination of traits not found in the true breeding parental generation; also called recombinant
mendel’s law of independent assortment
two different genes will randomly assort their alleles during gamete formation (if they’re not linked)
genetic recombination
- the process in which chromosomes are broken and then rejoined to form a novel genetic combination
- the process in which alleles are assorted and passed to offspring in combinations that are different from those found in parents
multiplication method
a method for solving independent assortment problems in which the probabilities of the outcome for each gene are multiplied together
forked-line method
a method to solve independent assortment problems in which lines are drawn to connect particular genotypes
loss-of-function allele
an allele of a gene that encodes RNA or protein that is nonfunctional or compromised in function
pedigree
charts representing family relationships
pedigree analysis
genetic analysis using information contained within family trees; the aim is to determine the type of inheritance pattern that a gene follows
probability
the chance that an outcome will occur in the future
random sampling error
the deviation between the observed and expected outcomes
product rule
the probability that two or more independent outcomes will occur is equal to the product of their individual probabilities
binomial expansion equation
an equation used to solve genetic problems involving a given set of unordered outcomes
multinomial expansion equation
an equation used to solve genetic problems involving three or more types of unordered outcomes
hypothesis testing
one experimental approach for conducting science; involves the formation of a hypothesis, followed by experimentation, so that scientists may reach verifiable conclusions about the world
goodness of fit
the degree to which the observed data and data predicted from a hypothesis are similar to each other; if the observed and predicted data are similar, the goodness of fit is high
null hypothesis
a hypothesis that assumes there’s no real difference between the observed and expected values
chi square test
a commonly used statistical method for determining the goodness of fit; method can be used to analyze population data in which the members of the population fall into different categories
p values
in a chi square table, the probability that the deviations between observed and expected values are due to random chance
degrees of freedom
in a statistical analysis, the number of categories that are independent of each other
