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Definition
| Idea that genetic material from teh two parents blends together (like blue+yellow=green) |
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Definition
| Idea that parents pass on discrete heritable units (genes) |
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Definition
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Term
| Advantages of Pea plants for general Study: |
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Definition
- There are many varieties with distinct heritable
features, or characters (such as flower color);
character variants (such as purple or white flowers) are
called traits
– Mating of plants can be controlled
– Each pea plant has sperm-producing organs
(stamens) and egg-producing organs (carpels)
– Cross-pollination (fertilization between different plants)
can be achieved by dusting one plant with pollen from
another |
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Term
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Definition
| Referring to plants that produce offspring of the same variety when they self-pollinate |
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Term
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Definition
| Mating of two contrasting, true-breeding varieties |
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Definition
| The true-breeding parents |
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Term
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Definition
| Hybrid offspring of the P generation |
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Term
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Definition
| When F1 individuals self-polinate they produce these |
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Term
| Pea Plant Characters Used |
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Definition
-Flower Color
-Flower Position
-Seed Color
-Seed Shape
-Pod shape
-Pod Color
-Stem Length |
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Term
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Definition
Any of teh alternative versions of a gene that produce distinguishable phenotypic effects.
Each character an organism inherits two alleles, one from each parent. |
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Term
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Definition
| An allele that is fully expressed in teh phenotype of a heterozygote |
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Term
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Definition
| An allele whose phenotypic effect is not observed in a heterozygote |
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Term
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Definition
| States that two alleles for a heritable character separate (segregate) during gamete formation and end up in different gametes |
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Term
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Definition
| Diagram for predicting the results of a genetic cross between individuals of known genetic makeup |
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Term
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Definition
| Organism with two identical alleles for a character |
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Term
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Definition
An organism that has two different alleles for a gene controlling that character.
(Unlike homozygotes, heterozygotes are not true-breeding) |
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Definition
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Term
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Definition
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Term
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Definition
| Breeding the mystery individual with a homozygous recessive to determine whether an individual is either homozygous dominant or heterozygous |
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Term
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Definition
Individuals that are heterozygous for one character.
(A cross betweens uch heterozygotes is called a monohybrid cross) |
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Term
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Definition
Organism that is heterozygous for two characters.
(Dihibrid cross, a cross between F1 dihybrids, can determine whether two characters are transmitted to offspring as a package or independently.) |
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Term
| Law of Independent Assortment |
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Definition
| States that each pair of alleles segregates idnependently of each other pair of alleles during gamete formation |
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Term
| Inheritance of characters by a single gene may deviate when... |
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Definition
- When alleles are not completely dominant or
recessive
– When a gene has more than two alleles
– When a gene produces multiple phenotypes |
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Term
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Definition
| Occurs when phenotypes of the heterozygote and dominant homozygote are identical |
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Term
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Definition
| Phenotype of F1 hybrids is somewhere between teh phenotypes of the two parental varieties (Red+White=Pink) |
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Term
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Definition
| Two dominant alleles affect the phenotype in separate, distinguishable ways (Heterozygotes: Both phenotypes expressed) |
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Term
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Definition
is a fatal disease; a dysfunctional
enzyme causes an accumulation of lipids in the
brain
– At the organismal level, the allele is recessive
– At the biochemical level, the phenotype (i.e.,
the enzyme activity level) is incompletely
dominant
– At the molecular level, the alleles are
codominant |
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Term
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Definition
| Blood groups have multiple alleles. Three alleles attaches either A or B carbohydrates to red blood cells: I^A, I^B, and i. |
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Term
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Definition
| Most genes have multiple phenotypic effects, a property called pleiotrophy. (example, pleiotrophic alleles are responsible for teh multiple symptoms of certain hereditary diseases, such as cystic fibriosis and sickle-cell disease) |
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Term
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Definition
| A gene at one locus alters the phenotypic expression of a gene at a second locus. (Example: mice and many other mammals, coat color depends on two genes. One gene determines the color, other gene determiens whether it will show or not) |
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Term
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Definition
| Characters that vary in the population along a continuum |
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Term
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Definition
| An additive effect of two or more genes on a single phenotype. (Example: Skin color in humans) |
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Term
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Definition
| The phenotypic range of a genotype when influenced by the environment. (Example: Hydrangea flowers of the same genotype range from blue-violet to pink, depending on soil activity) |
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Term
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Definition
| Such characters are called multifactorial because genetic and environmenet factors collectively influence phenotype |
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Term
| Why aren't Humans good for genetic research?! |
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Definition
– Generation time is too long
– Parents produce relatively few offspring
– Breeding experiments are unacceptable |
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Term
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Definition
A family tree that describes the interrelationships of parents and children across generations.
Inheritance patterns of particular traits can be traced and describe dusing pedigrees. |
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Term
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Definition
| Heterozygous individuals who carry the recessive allele but are phenotypically normal (i.e., pigmented) |
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Term
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Definition
| Recessive condition characterized by a lack of pigmentation in skin and hair |
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Term
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Definition
- (i.e., Makings between close relatives) increase the chance of mating between two carriers of the same rare allele.
- Most societies and cultures have laws or taboos against marriages between close relatives. |
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Term
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Definition
- Most common lethal genetic disase in the U.S. One out of every 2,500 people in the European Descent.
- Defective or absent chloride transport channels in plasma membranes. Symptoms include mucus buildup in internal organs and abnormal absorption of nutrietns in the small intestine. |
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Term
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Definition
- Affects one out of 400 African-Americans.
- Cause by the substitution of a single amino acid in the hemoglobin protein in red blood cells. Symptoms include physical weakness, pain, organ damage, and even paralysis. |
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Term
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Definition
| Form of dwarfism caused by a rare dominant allele. (dominant alleles that cause a lethal disease are rare and arise by mutation) |
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Term
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Definition
- Degeneratiev disease of the nervous system.
- No obvious phenotypic effects until 35-40 years of age. |
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Term
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Definition
The liquid that bathes the fetus is removed and tested
(Takes several weeks) |
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Term
| Chorionic Villus Sampling (CVS) |
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Definition
A sample of the placenta is removed and tested
(Takes several hours) |
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Term
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Definition
| Allow fetal health to be assessed visually in utero |
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