Chapter 2 Flashcards
Gregor johann Mendel
Priest who went to the university of Vienna to study physics and natural history, went on to carry out cross experiments with peas
Cross or hybridization
When two distinct individuals with different characteristics are bred to each other
Offspring are called hybrids
Gamete
Haploid reproductive cells that fuse to form a zygote
Plant reproduction
Pollination: make gametes (sperm) are produced within pollen grains that form in anthers and female gametes (eggs) are produced within ovules that form ovaries. A pollen grain lands on stigma which stimulates growth of pollen tube, Sperm travels to ovule and fertilization takes place when sperm enters micropyle and fuses with egg cell
Self-fertilization
Pollen and eggs are derived from the same plant
Cross-fertilization
Pollen from one plant, placed on the stigma of another plant
True breeding strain or true breeding line
A variety that continues to produce the same trait after several generations of self fertilization
Single factor cross
A cross in which an experimenter observes one character
Monohybrids
A cross between two parents with different variants for a given character produced single character hybrids
Parental generation or P generation
True breeding plants that differed in a single character
F1 generation
First filial generation (son)
Produced by P crossing which is the crossing of true breeding parents to each other
Dominant
When one variant is dominant over another
Recessive
When a variant is masked by the presence of a dominant trait but appears in subsequent generations
Particulate theory of inheritance
The genetic determinants that govern traits are inherited as discrete units that remain unchanged as they are passed from parent to offspring
Gene
A unit of heredity that may influence the outcome of an organism’s traits
Allele
An alternative form of a particular gene
Mandela law of segregation
The two copies of a gene segregate from each other during the transmission from parent to offspring
Genotype
Genetic composition of an individual
Phenotype
Observable traits of an organism
Punnett square
A menthol proposed by British geneticist Reginald punnett to predict offsprings genotype with the parents genotypes
Two factor crosses
The inheritance of two different characters within the same group of individuals
The law of independent assortment
Two different genes will randomly assort their alleles during the formation of haploid cells
Genetic recombination
When an offspring receives a combination of alleles that differs from those in the parental generation
2 mechanisms: independent assortment and crossing over
Independent assortment
The pairs of chromosomes a sort themselves during the process of meiosis. When two different genes are found on different chromosomes, they randomly assort into haploid cells.
