Hereditary Terms

polygenic

traits that are determined by many different genes

traits

inherited in a simple enough way that we can use them to learn basic principles of genetics

chromosomes

most genetic information of a cell is organized in bundles of DNA called __________

genes

chromosomes contain _______, which code for the same traits, but the specific details of that trait may vary

homologous chromosomes

the maternal and paternal chromosomes of a pair

autosomal choromosomes (autosomes)

chromosomes 1-22

sex chromosomes

chromosomes that make up the 23rd pair of chromosomes that determine the sex of the person

meiosis

occurs only in germ cells (reproductive cells) and results in the formation of the ovum or sperm with a single set of 23 chromosomes.

gametes

sperm and ovum (eggs) are called:

haploid

containing only one set of 23 chromosomes

zygote

when sperm meets ovum at fertilization.

receives 23 chromosomes from the mother and 23 chromosomes from the father, totaling to 46 chromosomes

diploid

contains 46 chromosomes

spermatogonium

original male diploid cell that undergoes meiosis

oogonium

original female diploid cell that undergoes meiosis

mitosis

cells reproduce by duplicating their chromosomes and dividing in two

genotype

the combination of alleles that the person has for a particular trait.

phenotype

the physical expression of the genotype- what you can observe

heterozygous

inherited 2 different genes, but only the dominant shows.

ex: Bb, brown(B) vs. blue(b) eyes. they will receive the brown eyes

homozygous

receive two of the same genes

ex: BB brown(B) and brown(B)

dominant

the expressed trait (visible)

recessive

the masked trait

allele

similar genes on homologous chromosomes

ex: the eye genes of the parents, the hair genes of the parents

carrier

the heterozygous person, who has normal appearance (phenotype) is called a ________.

sex-linked

a trait that’s inheritance is dependent on sex

Punnett square

a table used to visually determine the possible outcomes of the offspring’s traits