concepts of inheritance

long tangled thread like structure in the nucleus of an inactive cell made up of DNA

a chromosome that is a thread like structure made up of DNA that carries hereditary information in the form of genes

a segment of DNA or chromosome that code for a particular characteristics

two or more versions or forms of a gene which are located at the same position or genetic locus on a chromosome

an allele that masks or suppresses the expression of the allele partner on the chromosome pair and the dominant characteristic is seen in the homozygous and heterozygous state

an allele that is suppressed when the allele partner is dominant. the recessive trait will only be seen if both alleles for the trait are homozygous recessive

the physical characteristics or traits of an organism that are produced by the interaction of the genotype and the environment (the physical expression of one or more genes)

the genetic makeup of an organism

when two alleles that control a single trait on the same locus are different

when two alleles that control a single trait on the same locus are identical

one allele that is dominant and the other is recessive such that the effects of the recessive allele is masked by the dominant allele in the heterozygous condition

neither one of the two alleles of a gene is dominant over the other resulting in an intermediate phenotype in the heterozygous condition

both alleles of a gene are equally dominant whereby both alleles express themselves in the phenotype in the heterozygous condition

he is regarded as the father of genetics for his work on the garden pea plant that helped explain how genes are passed down from parent to child (how variation arises from the same species)

• he knew he would control their reproduction, by artificially cross-pollinating them, by transferring pollen by hand from one plant to another • pea plants were easily grown in large numbers .(the more plants he used ,the more accurate his results will be) • only carried out his experiments on pure breeding plants

• seed shape and color • pod shape and color • flower position and color • size

(p1) parental generation phenotype (all are tall ) genotype(Tt) meiosis gametes fertilization (F1) first filial generation genotype(Tt) phenotype(all are tall)

• an organism possesses two factors which separate or segregate so that each gamete contains only one of these factors (alleles) • when gametes form during meiosis ,the two factors (ALLELES) are separated or segregated .A gamete contains one of the two factors (ALLELES ) from each parent

• the various factors (ALLELES) controlling the different characteristics are separate entities ,not influencing each other in any way ,and sorting themselves out independently during gamete formation

• when two homozygous organisms with contrasting characteristics are crossed , all the individuals of the F1 generation will display the dominant trait • an individual that is heterozygous for a particular characteristic will have the dominant trait as the phenotype

refers to genetic crosses that involve only a single characteristic or trait

23 pairs of chromosomes

22 pairs of chromosomes are autosomes one pair of chromosomes are gonosomes

they determine whether an individual is female or male