Download ffiesletfcs n4444 - Xenia Community Schools

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JaU of the science words for this
lesson are about genetics, or the
branch of biolo$r that tells how
characteristics are passed from
parents to their young. Read the
lesson wo_1ds, Then read the
passage. Underline context clues
that help you decide what the
lesson words mean.
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mutati*m
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Has anyone ever told you that you
look just like your father or mother?
People are born with characteristics
that they
i
and other ancestor
cteristics from
parents to their young. For example,
a person's body size can be affected
by diet and exercise, but it is also
affected by heredity.
The human body is made up of cells.
The nuclens, or central pafr, of each
cell is filled with chromosomes. A
chromosome is the part of the cell
that contains the genes that determine
what characteristics a person will
have. A gene is the part of a cell that
controls a living thing's qualities and
growth. Each cell contains 23 pairs of
chromosomes. One chromosome in
each pair comes from the mother and
one comes from the father.
Genetics is the study of how
characteristics are passed from one
generation to the next generation.
Each characteristic, or trait, can
be dominant or recessive. The
7,4
brown eye trait is dominant, or
stronger, than the blue eye tratt,
which is recessive, or weaker. So
how do two brown-eyed parents
produce a blue-eyed child? If the
mother's chromosomes for eye color
are brown-blue and the father's are
brown-blue, the child could receive
the recessive gene from each parent,
giving him blue eyes.
Does adaptation or adjusting to
one's environment affect physical
traits? Over time, physical traits in
people or animals can adjust to their
surroundings. Scientists have found
that people who have lived for many
thousands of years in sunny places
have darker eyes. Darker eyes
provide more protection from the
sun's rays. They have also found that
people who have lived for thousands
of years in cloudier and cooler places
have lighter colored eyes.
A number of illnesses and medical
conditions are caused by a mutation
in a gene or set of genes. A mutation
is when an animal or plant develops
different characteristics because of a
change in its genes or because a gene
is missing. Certain mutations cause
illness. However, others do not cause
human problems because the body
undergoes cellular repairs and is
able to correct the problem. These
repairs, relating to the small basic
units of living things, are of great
interest to scientists. If they come to
understand the ways that the body
heals itself, scientists can help to
improve people's health.
Next time someone tells you that
you look like your mother or father,
think about it in a different way!
Using (ontext Ques Use the context clues you underlined in
the correct lesson word for each meaning.
the passage to write
1.
the study of how characteristics are passed from one
generation to another
2.
the part of a cell that carries the matter that
determines characteristics
3,
the process of developing different characteristics
because of a change in the part of a cell that
determines these characteristics
4.
the changrng over time of a characteristic so that
has a better chance of living in its surroundings
p
stronger, when speaking of cells that determine
characteristics
6.
the central part of a cell
7.
a distinguishing characteristic
or quality that a person has
8.
to get certain traits from your
parents and ancestors
9.
the passing of ch aracteristics
from parents to their young
O.
it
10.
relating to asmall basic unit in
living things
11.
weaker, when speaking of cells
that determine characteristics
12.
the part of a cell that determines the characteristics
a living thing will have
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True or Fafse?
Write True if the sentence
is true.
Write
False if
it is not.
1. A mutation is the process of a change
in characteristics.
2. People inherit certain qualities from parents
or ancestors.
3. Something
4.
that is recessive is powerful.
Heredity is the passing of qualities from parents
to young.
p
O.
A gene is a central part of a cell.
6. A
7"
trait is a quality that
a person has.
A chromosorne contains the genes that determine
someone's qualities.
8.
Genetics is the study of disease.
9. Something
that is dominant is weaker.
10.
Cellular refers to a small basic unit in a living thing.
11,
It is impossible for a trait to undergo an adaptation.
L2. A
nucleus is the outer part of a cell.
Adaptation
make
can also mean "to change something to
it suitable for a new condition."
h{y adaptation to a new school was quicker than my
friends expected it would be.
.r
?6
tlfho Am l? The lesson words in the box are speaking for
themselves. Write the word that best fits the clue.
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1. I bring about different characteristics.
ffiffi
heredity
nucleus
adaptation
2. I pass parents' characteristics along to their childrelt.
gene
chromosome
3. I am an adjustment to my surroundings.
mutation
dominant
4. I am the functional unit that carries characteristics.
O.
7
I am weak and am found in blue-eyed people.
6.
I am the middle
7.
I am strong and am found in brown-eyed
8.
I am the part of a cell that houses the functional unit that
recessive
of a cell.
people.
determines
characteristics.
UsingVocabulary Rewrite each sentence, using a lesson word from
the box instead of the word or words in blue type.
ffi#ffiffiffi
inherit
9. Right-handedness is a more common quality than
trait
left-handedness.
cellular
genetics
10. We wonder if my little brother will receive double-jointedness from
our father.
11. Melissa wants to study the branch of biology
that deals with passing
down characteristics to the next generation.
12. His donation helped fund research about small units of
living matter.
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Word Map Complete the word map by writing examples of
physical traits that you might acquire from your parents or ancestors.
eye colo r
The word dominanf can be used in other contexts.
It can mean "having the most power" ot "the
most noticeable."'Which meaning is used in the
following sentences?
In spring, the dominant greens overshadow most
other colors.
Ir *y backyard, fire ants rule as the dominant
insects.
:
Think of a mutation or adaptation that might help humankind. On
separate pape[ write a short story about it. Describe the mutation and
tell what happens as a result. Use at least five lesson words in your story.
Then read your story aloud to your classmates. You may add -s, -ed, or
-ing to the lesson words if you need to.
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ftecking UtJhat You Know Circle the letter for the answer choice
that best completes the sentence or answers the q uestion.
1. Someone who studies
genetics will
learn about-
A planets.
C
B characteristics. D
nutrition.
rocks.
2. A mutation in an animal may cause
the animal to become-
A desolate.
B agitated.
3.
C frightened.
D sick.
If a quality is recessive, it
is-
A not as commor]. C often changrng.
B very common. f) very old.
4.
Cellular research deals with-
A electronics.
B maps.
C cells.
D phones.
7
O.
9. A trait is most like
A coincidence.
B symptom.
a-
C quality.
D legacy.
10. A gene can determineA thought.
B wealth.
C dialect.
D hair
color.
11. Which of the following describes a
chromosome?
A part of a car
B part of a cell
C part of a charter
D part of an amendment
Which part of a cell is the nucleus?
A the outer part
B the central part
C the most important part
D the easiest part to see
talk to someone about heredity,
you'd discuss-
6. To
Think about the meanings of the
dominant words. Then add two
more words to the web.
A
money and commerce.
judges
B
and juries.
C prejudice and injustice.
D parents and their young.
inherit a quality is most likeA developing it through practice.
B being born with it.
Aominatio
n
7. To
dominant
C being able to recogrtLze it.
D changing it through exercise.
8. A physical
might be
A food.
B mate.
adaptation in an animal
its-
C fur color.
D habitat.
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