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Mendel's Peas, Traits and Inheritance, and Meiosis

Terms in this set (49)

heredity
the passing of genetic traits from parent to offspring
self-pollinating plant
a plant that has male and female reproductive structures, can pollinate own and other flowers
true-breeding plant
a plant that when self-pollinated, creates offspring that have the same traits as the parents
cross-pollination
pollen from one plant fertilizes the ovaries of another plant, transportation = small animals and wind
ovule, ovary, style, stigma
parts of the pistil, the female reproductive structure of a plant
anthers, pollen, filament
parts of the stamen, the male reproductive structure of a plant
What are the other parts of a plant?
the sepal and the petal
characteristic
a feature that has different forms in a population
trait
the different forms of characteristics
What were the traits that Mendel worked with?
flower/seed/pod color, seed/pod shape, location of the flower on the plant, and plant height (7).
parent generation
the generation that produces the first generation offspring, have different traits in Mendel's experiments
first generation plants
offspring of parents, dominant trait
second generation plants
offspring of first generation plants, one fourth recessive trait
dominant trait
the same parent trait shared in first generation offspring, dominant
recessive trait
the parent trait that did not appear in the first generation offspring, but did appear in the second generation offspring
ratio
a relationship between two numbers, commonly a fraction
Gregor Mendel
European farm boy, monk monastery, science experiments, Vienna teaching training, studied, failed exam, back to monastery, explained recessive traits, pea plants, opened a "door" into genetic science
Mendel's Goal
to explain recessive traits
Why were peas a good choice?
grow quickly, many different kind with different traits, self- pollinating, true- breeding, cross- pollinating.
Mendel's First Experiment
crosses parents with different traits, first generation = all offspring have dominant trait, remove anthers of plant with "female role", cross- pollination, second generation = one- fourth recessive trait
Mendel's Second Experiment
crosses parents with different traits, first generation = all offspring have dominant trait, self- pollinate, second generation- one- fourth recessive trait
Mendel's Ratio
3:1 ratio, second generation offspring = one fourth recessive trait
Mendel's Conclusion
each trait has two forms, or two sets of instructions, one from each parent
allele
one of the two alternative forms of a gene that governs, or controls, a characteristic, dominant
genotype
the entire genetic makeup of an organism; also the combination of genes for one or more specific traits, both inherited alleles from each parent
heterozygous
an organism that has a genotype with dominant and recessive traits. capital and lowercase letters. hetero = different
homozygous
an organism with two dominant or two recessive traits, "all or nothing" properties, homo = same
phenotype
an organism's appearance or other detectable characteristic, outward apperance
Punnett square
four square used to organize all of the possible combinations of offspring genotypes from particular parents, uses both capital and lowercase letters
gene
one set of instructions for an inherited trait
albinism
inherited disorder that affects an plant or animals phenotype in several ways, ex. abnormal coloring
probability
the likelihood that a possible future event will occur in any given instance of the event, fraction or percentage
incomplete dominance
in Punnett square, each offspring has equal degree between dominant and recessive, occurs when one allele is not completely dominant over another, the two traits do not blend together, both alleles are expressed
what happens with the second generation offspring of an incomplete dominant trait?
Second Generation of Incomplete Dominant trait has three different traits out of four offspring.
dominance
the idea that one trait dominates another trait
"cases" of the two types of traits
dominant- capital letter, recessive- lowercase letter
which is dominant, darker or lighter pigments?
darker pigments
what is the difference between genes and alleles?
the relationship between genes and alleles is the same relationship between characteristics and trais, an allele is a type or form of a gene
how can probability be used with heredity?
to describe possible outcomes in offspring and the likelihood of each outcome.
explain why true-breeding second generation has one fourth recessive by using the Punnett Square.
First PS = dominant, TT, recessive, tt, all offspring, dominant trait, Tt; Second PS = both dominant = Tt, TT, Tt, Tt, and tt, one fourth recessive trait
Punnett Square probabilities
dominant trait = 75%, recessive trait = 25%, heterozygous = 50%, and homozygous recessive or dominant = 25%
where is a gene located?
on a chromosome, homologous chromosome, copy
If a parent has two different alleles, then what are the offsprings chances of getting either allele?
equal 50%- 50% , or 1/2 chance
calculating probabilities, ex. two probabilities consecutively then you..., ex. coin toss, two heads in a row is a ____ chance.
multiply, 1/2 chance x 1/2 chance = 1/4 chance
what are three exceptions to Mendel's theories?
incomplete dominance, one gene- many traits, and many genes- one trait, (environment)
what does one gene- many traits mean?
it means that one gene may influence more than one trait.
what does many genes- one trait mean?
it means that several genes may influence only one trait.
what is a factor of traits besides genes?
the environment
how do you calculate probability?
number of one of the possible outcomes/(over) the number of all of the total possible outcomes. To calculate multiplication involved probabilities, you can use a Punnett square.
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