Terms in this set (81)
An Austrian monk who founded the modern science of genetics: the scientific study of heredity.
He tended the monastery's garden and experimented with pea plants.
The delivery of characteristics from parent to offspring.
A process used to produce a new cell by sexual reproduction; male and female reproductive cells join.
*union of sperm and egg.
Sperm cells fertilize egg cells from within the same flower. It inherits all of its characteristics from the single plant that made it.
When fertilization reproduces from 2 parents rather than one. *Pollen from a different flower is used.
The offspring of crosses between parents with different traits.
Another name for hybrid.
Two of the same genes for a trait.
Ex: BB or bb
Another name for purebred.
First filial; the offspring;
The offspring of the offspring; second filial;
Contrasting forms of a gene.
Ex: Tall allele vs. short allele
Prevents other traits from showing ("B").
Trait is masked (hidden) by dominant trait ("b"). It needs 2 recessive genes to show the recessive trait.
Law of Segregation
Alleles segregate (separate) from each other in the formation of gametes- each gamete carries one allele for each trait.
Basically describes meiosis.
Law of Independent Assortment
States that genes for different traits can segregate independently during the formation of gametes. It helps account for the many genetic variations observed in plants, animals, and other organisms- even when they have the same parents.
Genetic makeup; it is inherited and more specific than the phenotype;
Physical traits; it is largely determined by the genotype;
Ratio= Tall to short
A mathematical diagram that can be used to predict the genotype and phenotype combinations of a genetic cross for offspring.
*Know how to do them!
TtHh x TtHh
Dihybrid cross outcome
How to figure out possible gametes with a given genotype.
Law of multiplication
*Chance of having Aabbcc?
Alleles for different traits are inherited together because they are joined on the same chromosome.
Genes on the same chromosome that travel together.
Ex: Blonde hair and blue eyes.
The crossing of an individual of unknown genotype with a homozygous recessive individual to determine the unknown genotype.
Mendel's 4 principles of Heredity
1. Genes are units of heredity.
2. Some alleles are dominant or recessive.
3. Adults have 2 alleles for each trait which separate during meiosis.
4. Alleles separate independently during gamete formation.
4 exceptions to Mendel's Principles of Heredity
Incomplete dominance, co-dominance, multiple alleles, and polygenic traits.
Incomplete dominance and example
Cases in which one allele is not completely dominant over another. Some alleles are neither dominant nor recessive. The heterozygous phenotype lies somewhere between the 2 homozygous phenotypes.
Ex: RR x WW; offspring= RW
Co-dominance and example
Phenotypes produced by both alleles are clearly expressed.
Ex: In certain types of chickens, the allele for black feathers is co-dominant with the allele for white feathers. Heterozygous chickens have a color described as "erminette," speckled with black and white feathers.
Multiple alleles and example
Genes with more than two alleles.
Ex: A rabbit's coat color is determined by a single gene that has at least 4 different alleles. The alleles display a pattern of simple dominance that can produce 4 coat colors.
Polygenic trait and example
Traits controlled by two or more genes.
Often show a wide range of phenotypes.
Ex: At least 3 genes are involved in making the reddish-brown pigment in the eyes of fruit flies. 4 different genes control the variety of skin color in humans.
A specific characteristic of an individual.
When objects that are self pollinating would produce offspring identical to themselves.
Factors which are passed from parent to offspring.
A sequence of DNA.
Principle of Dominance
States that some alleles are dominant and others are recessive. An organism with at least one dominant allele will exhibit the dominant trait. An organism with a recessive allele will exhibit the recessive trait only when the dominant allele isn't present.
An entire set of genetic information that an organism carries in its DNA.
A micrograph of the complete diploid set of chromosomes grouped together in pairs, arranged in order of decreasing size.
It shows the diploid sets of chromosomes.
A chromosome that's not a sex chromosome.
Ex: Chromosomes #1-22.
One or two chromosomes that determines an individual's sex.
Sex cells; 23 chromosomes; 13 pairs;
Body cells; 46 chromosomes; 23 pairs;
A gene that helps determine skin and hair color.
Recessive alleles- red and light hair/skin.
Dominant alleles- darker.
Rh+ or Rh-
A gene for another cell surface protein on red blood cells.
*A blood factor that distinguishes Rh+ and Rh- blood types.
Traits that are inherited with sex chromosomes.
Appear more often in males than females because males only have one x chromosome.
Genes located on a sex chromosome.
All blood types
Pure A= AA
Hybrid A= AO
Pure B= BB
Hybrid B= BO
Type AB= AB
Type O= OO
Possible blood type donations
A can have A and O.
B can have B and O.
O can have O.
AB can have A, B, O, and AB.
*Positive can't have negative and negative can't have positive. Positive can have positive and negative can have negative.
AB; It can have any type of blood, but no other blood type can have it.
OO; Everyone can have it.
Blood type punnett squares and children possibilities
Look at "Blood Type And Inheritance" worksheet.
A small, densely staining structure in the cell nuclei of female mammals, consisting of a condensed, inactive X chromosome.
*X chromosome condensed.
Female calico cat color pattern
A female cat's fur has a mixture of orange and black spots because of having 2 X chromosomes that have 2 different alleles (black and orange). One x chromosome is switched off in certain parts of the body.
Male calico cat color pattern
A male cat's fur can only have spots of one color because it has one x chromosome.
A chart that shows the relationships within a family. It shows the presence or absence of a trait according to the relationships between parents, siblings, and offspring.
Shaded circle of square
A person expresses the trait.
Vertical line and bracket
Parents to the children.
Person does not express the trait.
Cystic fibrosis cause
Results from the deletion of 3 bases (nucleotide called Phe) in a gene. It is replaced by a protein called CFTR.
Cystic fibrosis symptoms
Thick, heavy mucus that clogs their lungs and breathing passageways.
Sickle cell anemia cause
Caused by a defective allele for beta-globin, one of two polypeptides in hemoglobin, the oxygen-carrying protein in red blood cells. It makes hemoglobin less soluble, causing the molecules to stick together when he blood's oxygen level is low.
Sickle cell anemia symptoms
Swelling chest pain
Failure of chromosomes to separate.
Ex: When non-disjunction occurs during meiosis, gametes with an abnormal number of chromosomes may result, leading to a disorder of chromosome numbers.
*Most devastating in meiosis 1.
When non-disjunction can occur
A disorder where there's an extra copy of a chromosome.
Ex: down syndrome.
Three sets of chromosomes; 69 chromosomes;
2N + N = 3N
Four sets of chromosomes; 92 chromosomes;
2N + 2N = 4N
Turner's Female symptoms
Sterile (unable to reproduce)
Sex organs are not developed properly at puberty.
Turner's Female genotype
Kleinfelter's Male symptoms
Offspring will always have the extra chromosome.
Kleinfelter's Male genotype