Heredity Notes
 Inherited Trait – a trait that can be passed down from your parents and
grandparents
 Not inherited traits are unique to you and include learned skills or abilities
 Heredity – the passing of traits and physical features from parents to their
children
 Gene – sets of instructions in each human cell that determines inherited physical
features and other traits
 Dominant Gene – a gene that is stronger and in control
 Recessive Gene – a gene that is weaker; not in control
 Learned Behavior – something that you are taught or learned through experience
 Acquired Trait –a trait that is either a learned behavior or a physical trait that
you were not born with (ie. a scar)
 The only people in the world with the same genes are identical twins
 Offspring – children or the baby of a parent (of plants and animals)
 Genes are from your parents and made of DNA that tells your body how to
grow
 Gregor Mendell discovered through work with pea plants that there were 2
genes, one dominant and one weaker gene
o 1 dominant and 1 recessive = dominant
o 2 dominant = dominant
o 2 recessive = recessive

Every cell has a copy of your genes
 There are two genes for every trait, one from your mom and one from your
dad
 A clone is an identical copy of a parent (either human, plant or animal… usually
just plants for right now…)
 About 30,000 genes are in each cell
 Reginald Punnett created the Punnett Square which determines the probability
of what trait a child may have from its parents
o Examples of dominant traits include: dark hair, dimples, brown eyes, curly
hair, extra toes, stubby fingers, immune to poison ivy, big eyes, widow’s
peak, double jointed, extra fingers, full head of hair, right-handedness,
free-hanging earlobes
o Examples of recessive traits include: light hair, no dimples, thin lips, single
jointed, long fingers, straight hair, scratch scratch (allergic to poison ivy),
20 fingers and toes, baldness, attached earlobes, left-handedness, blue,
hazel, gray and green eyes
 Your height is not solely based on genes, it can also be affected by your
nutrition
 Sometimes parent plants like strawberries can clone itself
 A trait is a physical or personality feature
 Animals and plants will change as they grow up, they will look like their parents
 Everything about twins is not identical, they can each gain new learned
behaviors
 You CANNOT get genes from your aunt or your uncles… it must be from your
parents or their parents
 Some inherited traits can include: eye color, length of fingers, shape of eyes,
hair color, shape of nose, skin color, dimples, earlobes, vision, freckles, all basic
functions of humans (ie,,,walking, speaking, hearing..)
 Some acquired traits include: how to read, how to play football, a scar, how to
spell and write, how play sports, how to speak languages, length of nails, ANY
learned behaviors
 Freckles are darkened by the sun and may appear more in the summer time…
you inherit the trait to have them (whether you can see them or not)
 Sometimes traits change of time, hair color and eye color can sometimes change
 A population is a group of organisms that live in the same area at the same time