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Heredity
An organism gets its traits, or characteristics, from its parents and its environment.
Inherited Characteristics
Anything an organism gets from its parents is inherited. Inherited traits of organisms are
decided before birth (or germination). Examples of inherited traits in humans are: eye
color, hair color, dimples, ability to roll the tongue, and type of earlobes (attached or
detached). Organisms also inherit behaviors. For example, humans do not have to be
taught how to eat or sleep.
Type of earlobe is an inherited trait. The picture on the left shows a detached earlobe,
while the picture on the right shows an attached earlobe.
Because they inherit many traits, children often look similar to their parents. However,
children do not look exactly like their parents. Some of what children inherit stays
hidden. Other things are affected by the environment.
Characteristics that are Not Inherited
People get some of their traits from what happens to them or from the kind of
environment they live in. These traits are called learned characteristics or acquired
traits. Scars, tattoos, clothing, hairstyles, and pierced ears are acquired traits because
they are not inherited from parents.
Any characteristic that a person gets from experience is acquired, not inherited. For
example, dislikes of some foods can be acquired. Children can get a love of music from
their parents by learning instead of inheriting.
This girl inherited her hair color from her mother, but the girl will have to learn to play the
guitar.
Inherited & Acquired
Most traits are a combination of inherited and acquired. In humans:

Skin color is inherited, but tanning can make it darker.

A person inherits the ability to freckle, but being in the sunlight changes the size and
number of freckles.

Height is inherited, but people who do not get enough food while growing will be
shorter.
Many characteristics are affected by an organism's environment.
Traits in Plants
Plants inherit traits such as:

flower color

flower position

seed color

seed shape

pod shape

pod color

leaf pattern

stem length.
This pepper plant inherited its pod shape and color from its parent plants.
Some plant characteristics are acquired from the environment, not inherited. For
example, if a plant gets too much sunlight or does not get enough water, its leaves may
turn brown.
The leaves of this palm tree have turned from green to brown. Maybe the tree did not
get enough water.
Also, in some kinds of plants, flower color is affected by the kind of soil the plant is
growing in. In these plants, flower color is both inherited and acquired.
Traits in Animals
Animals inherit traits such as:

fur color

fur length

eye color

length of tail

ear shape

patterns such as spots, stripes, or patches
Most of these traits can be affected by the environment. For example, a dog may inherit
long fur, but it may acquire short fur if the dog's owners shave it.
A horse's color and the color of the mane are inherited traits. The horse's height is both
inherited and acquired. These characteristics are different from one horse to another.
However, all horses can eat grass as part of their healthy diet. This is also inherited.
This horse inherited its light color and dark mane and tail from its parents.
Animal characteristics such as having docked tails (tails that have been cut short) are
acquired, not inherited.
This lamb's tail has been cut short to help keep the animal clean. A short tail is not one
of the lamb's inherited traits.
Parents & Offspring
The children of an animal are called its offspring. The offspring of a parent may be very much
like their parents, but they are not exactly like their parents.
Many young offspring look very much like their parents, only smaller. For example, this
baby monkey is white with black ears and a black face, just like its mother. It is only
smaller.
Sometimes offspring look somewhat like their parents, but they are also a good deal
different. For example, baby birds have the same beak, feet, and body shape as their
parents, but they have downy feathers and small wings that make them look a bit
different from their parents. Look at the geese in the pictures below.
The baby geese, called goslings, hatch out of eggs. When they are very young, they are
small, yellow, and fuzzy. As the babies grow older, they get larger and change colors so
that they are colored more like their mother. When the babies are fully grown, they look
like their mother in almost every way.
Individual Variation
Each individual organism within the same species can be a little different. This is called
individual variation.
While organisms of the same species are generally alike, each individual can be a little
different. Some variations give an organism an advantage in its environment, while
other variations might reduce the ability of the organism to survive. Still other variations
might have no effect on the survival of the organism at all.
For example, imagine that a gazelle is born with longer legs than most other gazelles. If
longer legs helped the gazelle to outrun predators and therefore to survive longer than
most other gazelles, the long-legged gazelle would likely live longer and produce more
offspring.
The gazelle on the left would be more likely to survive because it could run faster than
the gazelle on the right.
Now, imagine a kind of plant that usually has long roots to reach water in the ground. If
an individual is born with shorter roots, this could make it less likely to survive because
it could not get water.
The plant on the left would be less likely to survive because it could not reach water as
well as the plant on the right.
Variations can also affect an organism's ability to reproduce. Some individuals can find
mates easier than others. For example, male peacocks with long tail feathers are able
to attract mates more easily than males that have shorter tail feathers. This means that
males with long tail feathers are able to reproduce more easily.
The male peacock on the left would likely be able to reproduce more easily than the
male on the right because of its longer tail feathers.
Variations in behavior can also make an individual more or less likely to survive or
reproduce. For example, imagine that there are two squirrels living in a neighborhood.
One of the squirrels has learned how to get food out of the bird feeders that humans
have put up in their yards. The other squirrel does not know how to get into the feeders.
The squirrel that can get food out of the bird feeders is more likely to survive because it
has an extra food source that the other squirrel does not have.