GOOD CHOICE LANGUAGE CENTER
AND
GED PREPARATION CENTRE
(Biology)
This book belongs to ______________________
1
Science Lesson 1 (The scientific method)
This lesson introduces you to science as an area of study and to the
scientific method.
What is science?
Science is the study of the world around us and underneath us. Science goes
beyond our world, into space. With science, people have saved lives and
made many other scientific advancements.
Science is a big, complicated process. But we can all understand how
science is done. We will learn some really interesting things along the way.
Scientists use three things to learn about the physical and natural world.
They are:
•
•
•
observation (looking at things)
research (gathering information)
experiments (trying things to see what happens)
Scientists want to be sure their facts are correct. They use careful systems
and test their ideas. This is the scientific method.
What is the scientific method?
The scientific method is a way to ask and answer questions about what you
observe.
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Creating experiments and analyzing results can be very complicated. You
will not be expected to know all about it. But you should be able to explain
the steps of the scientific method and create examples.
Here are the steps of the scientific method:
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Hypotheses
The diagram above includes the word “hypothesis” (plural: hypotheses).
A hypothesis is a guess based on information: what some people call “an
educated guess.”
Here is an example of a hypothesis. You observe that a cup of tea is too hot
to drink. But after ten minutes it has cooled to a good drinking
temperature. Your question is why? Your hypothesis (guess) may be that
tea cools over time.
You can test this hypothesis by observing two more cups of tea and finding
that the tea does get cooler. You may apply your hypothesis to other hot
liquids and even hot food. You observe that the liquids and solids
eventually reach room temperature.
However, if you have an ice cube, it will get warmer when it is taken out of the
freezer. It will melt. With this information, you might hypothesize that
objects colder than room temperature will warm up until they reach room
temperature. When your tests show that this hypothesis is also correct, you may
form another hypothesis: liquids and solids always cool down or heat up to room
temperature.
Scientists often find that their hypotheses are wrong. This is not a failure. Getting
rid of wrong ideas helps scientists get closer to the truth. Even when scientists say
a hypothesis is “correct” or “confirmed,” they are willing to be proved
wrong. That’s because some future scientist might discover a new idea that
shows an accepted fact in a new light.
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TEST TIP: HOW TO APPLY THE SCIENTIFIC METHOD
In your science test, you will need to answer questions that test your knowledge of
the scientific method. Before you take your science test, you should understand
and remember the steps. Then you will be able to recognize examples when they
come up in your test. Also, you will be able to apply the steps if you are asked to
create and analyze an experiment.
Let’s read a story about drinking water. Then we’ll apply the scientific method to it.
Water quality in Joseph’s community
Joseph lives in Glendale, where people are getting a stomach bug called Giardiasis.
Many of Joseph’s neighbors have been getting sick, but not all of them. He
wonders why some of them are not infected. Joseph asks around and finds out
that his healthy neighbors always boil their drinking water. Joseph reads about
Giardiasis and finds out it comes from Giardia. Giardia is the name of a bug that
sometimes gets into water systems. He also reads that many bugs cannot live in
boiling water. He wonders if the boiling water kills the Giardia bug. Joseph decides
to check and see. He collects water from his faucet and divides it into two jars. He
boils the water in one container. Then Joseph buys a water test kit and tests the
water in both jars. The unboiled water was infected with Giardia bugs. The boiled
water had no live bugs. Joseph quickly puts a notice on the community Facebook
page: Boil your water before you drink it!
QUESTION: Look back at the diagram that shows the seven steps of the scientific
method. Can you match the steps in the diagram to Joseph’s story?
• Observation: Lots of Joseph’s neighbors have been getting sick, but not all of
them.
• Question: He wonders why some of them are not infected.
• Background research:
1) Joseph asks around and finds out that his healthy neighbors always boil their
drinking water.
2) Joseph reads about Giardiasis and finds out it comes from the bug Giardia.
3) He also reads that many bugs cannot live in boiling water.
• Form hypothesis: He wonders if the boiling water kills the Giardia bug.
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• Test with experiment: He collects water from his faucet and divides it into two
jars. He boils the water in one container.
• Analyze results: Joseph buys a water test kit and tests the water in both jars. The
unboiled water was infected with Giardia bugs. The boiled water had no live bugs.
• Report results: Joseph quickly puts a notice on the community Facebook page –
Boil your water before you drink it!
So your test tip for this lesson is to memorize the steps of the scientific method.
Then you can easily recognize or apply them in your test.
WHAT WE LEARNED
•
1
Science is the study of the physical world and space.
•
2
Scientists use observation, research, and experiments.
•
3
The scientific method is a way to test ideas.
•
4
A hypothesis is a guess that scientists test using the scientific method.
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NEW WORDS
analyze
look at something in detail and find its meaning. In science, this means look at
informa�on to see if an experiment has an effect.
eliminate
get rid of or remove
experiment
a scien�fic procedure to test why something happens
hypothesis
a possible explana�on of why something happens. The plural of hypothesis is
hypotheses.
observa�on
seeing, hearing, or no�cing something
report
write about something you have observed, researched or tested
research
gather informa�on
scien�fic method
set system of observa�on, measurement, and experiment to test a hypothesis
Quiz
1.A farmer notices that the tomato plants in his field grew more tomatoes than
the tomato plants under a tree by the barn. He also noticed that the tree
protected the plants under it from the rain.
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QUESTION: Which part of the scientific method is this?
•
Observation
•
Question
•
Hypothesis
•
Analyze results
2.The farmer of the tomato plants wonders, “Do you grow more tomatoes
when you give a plant more water?”
QUESTION: Which part of the scientific method is this?
•
Observation
•
Question
•
Hypothesis
•
Analyze results
3. The farmer thinks his tomato plants will grow more fruit if they receive more
water.
•
Observation
•
Question
•
Hypothesis
•
Experiment
•
Analyze results
4. The farmer grows two rows of tomatoes. The farmer waters one row with 1
liter of water per plant per week. The farmer waters the second row with 2 liters
of water per plant per week. The farmer does this for one month. Which part of
the scientific method is this?
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•
Background research
•
Experiment
•
Hypothesis
•
Report results
5. After one month of watering, the farmer measures the height of the
tomato plants in each row. He compares the two rows. He counts how
many tomatoes are growing on each plant, and compares the two rows.
Which part of the scientific method is this?
•
•
Background research
•
Hypothesis
•
Experiment
•
Analyze results
•
Report results
1. What is the first step in the scientific method?
A. Form hypothesis
B. Test with experiment
C. Observation
D. Report results
2. What do scientists do after making an observation?
A. Share results
B. Ask a question
C. Analyze data
D. Form a hypothesis
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3. What is the purpose of background research in the scien�fic method?
A. To test the hypothesis
B. To report the findings
C. To guess the answer
D. To find information already known about the topic
4. A hypothesis is best described as:
A. A conclusion drawn from results
B. A summary of other scientists' work
C. An educated guess to answer a question
D. A tool used for observation
5. What comes immediately after forming a hypothesis?
A . Testing with an experiment
B. Background research
C. Sharing the results
D. Asking a question
6. What is the purpose of analyzing results in the scientific method?
A. To design the next experiment
B. To determine if the hypothesis is correct
C. To ask a new question
D. To make a new observation
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7. What do scientists do after analyzing their results?
A. Form a new hypothesis
B. Do background research again
C. Observe a new experiment
D. Report their results
8. In which step do scientists design an experiment?
A. Analyze results
B. Test with experiment
C. Background research
D. Report results
9. Which step involves communicating findings with others?
A. Form hypothesis
B. Question
C. Test with experiment
D. Report results
10. Why is the scientific method important?
A. It provides a structured way to investigate and understand the world
B. It ensures every scientist finds the same result.
C. It allows scientists to skip steps and save time.
D. It helps scientists memorize facts quickly.
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Read the descriptions and write the numbers next to the words.
Observation
question
Experiment
analyze results
background research
hypothesis
report results
1. If salt is added to water, then a lime will float because salt water is
denser than plain water. _______
2. In plain water, the lime sinks. In salt water, the lime floats.
This shows that salt water is denser and supports the lime better.
3. You observe that a lime usually sinks in plain water, but someone says
it might float in salt water.
4. You learn that salt increases the density of water. If the water becomes
denser than the lime, the lime might float.
5. You conclude that a lime can float in salt water because the increased
water density creates more buoyant force. You can share this result in
a science journal or classroom discussion.
6. Can adding salt to water make a lime float?
7. Fill two cups with the same amount of water. Add several tablespoons
of salt to one cup and stir until dissolved. Drop one lime into the plain
water and one into the salt water. Observe what happens.
https://youtube.com/shorts/xsKqEsGEmQw?si=lY7KV1KYnZHNBBbC
Group Project: Present seven steps of scientific method and experiment
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Lesson-2 (Using data)
What is data?
Numbers are one kind of data. But data is more than just numbers. Data is
information that is collected, measured, and recorded. Scientists use data to
make conclusions and share results.
For example, the records of the high and low temperatures each day are
data. The names of all the people who have been president of Nicaragua are
data. You have data connected to you. You have a name, a date of birth, and a
height. All these things are data.
Collecting or finding data often starts with a question. It could be anything from
“How often does the sun shine in my city?” to “How does my government spend
its money?” to “What is the fastest route to the grocery store?”
Types of data
The two major types of data are qualitative and quantitative:
•
Qualita�ve data is informa�on about a quality. Descrip�ons of colors,
texture, or a process are all qualita�ve data. You can put qualita�ve data
into a category. You can categorize data in many ways. For example, a
soccer ball can be categorized as new or used. People might be babies,
children, or adults. Test ques�ons might be in the difficult category or the
easy category.
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•
Quan�ta�ve data is informa�on about a quan�ty, or number. The number
of soccer balls, the birth weight of infants, the price of flour, and a score on
a test are all quan�ta�ve data.
htps://youtu.be/g30cI4Kbhb4
Variables
Variables are things that can vary, or change. Some variables reflect a change over
time. The temperature at noon is a variable because it varies from day to day,
depending on the weather and time of year. If you collect this data for many
years, you can predict the temperature at noon for a particular date. You would
base your prediction on how warm and cold it has been on that same date in the
past.
When a measurement changes from subject to subject, it is also a variable. Height
is a variable because it changes from person to person.
There are two types of variables:
•
Independent variables are the ones you start with in an experiment. These
are independent of what happens in the experiment. Scientists may apply
or change variables to see what effect they have.
•
Dependent variables are what you want to learn about by performing your
experiment. They are changes that depend on the independent variables.
Here is an example of the two types of variables: In our last lesson, the
temperature of a hot cup of tea cooled over time. The temperature depended on
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how much time had passed. In this example, the time is the independent variable
(it happens anyway), and the temperature of the tea is the dependent variable (it
happens because of time passing).
Using samples
Sampling is an important part of conducting research. You have to decide how
many tests to perform, or people to observe, or places from which to collect data.
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Random samples
Control groups
When scientists test medicines, they often use control groups to make sure that
they are seeing real results. A control group is used for comparison. Joseph’s
water quality experiment used unboiled water so he could compare the boiled
water. In another example, a control group could be a group of people who do
not get the medicine being tested.
Showing data
You can show data in words, numbers, or using pictures called diagrams. People
often understand data better when they can see it. Diagrams showing number
data are called graphs or charts. They make it easy to see patterns in data and
find information.
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Line graphs
A line graph is good at showing continuous data. Scientists often use line graphs
to show the results of their experiments. With a line graph, they can show the
relationship between variables.
https://youtu.be/n2YkbdNORp8
Charts
Charts are a kind of graph. You can use charts to show information in categories.
Hair color, types of fruits, or countries where people were born are variables that
are also categories. Charts are not good for continuous data, like line graphs. They
present data that can be counted in separate chunks.
One example of a chart is a histogram, which is a type of bar chart. Bar charts
show data in bars of different heights. On a regular bar chart, each bar shows one
variable, such as types of fruit sold. On a histogram, the bars show groups, or
ranges – for example, the amount of fruit sold in a series of 10-year periods.
https://youtu.be/c02vjunQsJM
https://youtu.be/oaJHlJtleuU
https://youtu.be/bbzZszBF5z8
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TEST TIP: HOW TO READ A LINE GRAPH
You will see several graphs and charts in your science test. To answer ques�ons
about them, you need to know what they are about and how to read the data in
them.
A good graph always has a clear �tle that tells you what it is about. It will have
labels for different parts, too. It may also have a key to explain colors or shapes
used in the graph.
In your science test, carefully read the �tle, labels, and key to understand what
the graph is showing you.
The �tle of the graph below says it is about the height of people around the world
over a period of �me. The labels tell us that one set of numbers shows the year,
and the other set of numbers shows the height of people in cen�meters.
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The horizontal (across the page) line of a graph is called the x-axis. The ver�cal (up
the page) line of the graph is called the y-axis. The axes of the graph show the
variables. Usually, the independent variable will be on the x-axis and the
dependent variable on the y-axis. This makes it easy to see how the dependent
variable changes as the independent variable changes. On our graph, the
independent variable, on the x-axis, is years. The dependent variable, on the yaxis, is people’s height.
There are a lot of colored lines on the graph. The key under the graph explains
what each color means. In this graph, each color stands for a different region of
the world.
Now that we understand what the graph is showing, let’s learn how to analyze the
informa�on in it.
The lines on the graph show certain paterns. One patern is that all of the lines
have risen from the beginning. This shows that the average height of all people
increased between 1810 and 1980.
You can get details from the graph, too. The purple line represen�ng Eastern
Europe and Central Asia shows that the average height in that region in 1810 was
less than 165 cm. In 1980, the average height in the same region was more than
175 cm.
You can practice finding data in graphs and charts in the quiz at the end of this
lesson. There will be more examples to practice on in later lessons. You will be
good at reading charts and graphs when you finish the class!
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WHAT WE LEARNED
•
1
Data is a collection of information that has been measured or recorded.
•
2
Variables are things that are different between sets of data. An
independent variable is one that is not controlled. A dependent variable is a
variable that changes.
•
3
A sample is a representative selection of data. A random sample is one
where any subject may be chosen.
•
4
Graphs and charts are images that present data more easily and clearly
than words or numbers.
Matching game (To print)
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1.QUESTION: What was the average height of people from Latin America and the
Caribbean in 1960? Choose the best answer.
•
154 cm
•
167 cm
•
173 cm
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180 cm
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2. QUESTION: On what day of the week did the largest number of bank robberies
take place? You can type your answer in the blank.
___________________________
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3. QUESTION: What does the graph tell you?
•
Overall, the price of a bushel of corn did not change in the period from
January 2005 to January 2014.
•
Overall, the price of a bushel of corn decreased in the period from
January 2005 to January 2014.
Overall, the price of a bushel of corn increased in the period from
January 2005 to January 2014.
•
Suah’s pet cat has been acting strange lately, and Suah also notices that some of
the leaves on her houseplants have been eaten. Suah guesses that something in
one of the houseplants is causing the cat to act strangely. She decided to do an
experiment to see which plant was making her cat act strange. On Monday, she
hid one plant. On Tuesday, she hid a different plant. She notes how the cat
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behaves in the absence of each plant. After the cat has had one day away from
each plant, Suah has discovered which plant is causing her cat to act strangely.
4. QUESTION: Which of the following is/are the dependent variable(s) in Suah’s
experiment?
•
The second plant
•
The first plant
•
The cat's behavior
•
Both plants
Suah’s pet cat has been acting strange lately, and Suah also notices that some of
the leaves on her houseplants have been eaten. Suah guesses that something in
one of the houseplants is causing the cat to act strangely. She decided to do an
experiment to see which plant was making her cat act strange. On Monday, she
hid one plant. On Tuesday, she hid a different plant. She notes how the cat
behaves in the absence of each plant. After the cat has had one day away from
each plant, Suah has discovered which plant is causing her cat to act strangely.
5. QUESTION: Which is/are the independent variable(s) Suah’s used in her
experiment?
•
The second plant
•
The first plant
•
The cat's behavior
Both plants
Suah’s pet cat has been acting strange lately, and Suah also notices that some of
the leaves on her houseplants have been eaten. Suah guesses that something in
one of the houseplants is causing the cat to act strangely. She decided to do an
experiment to see which plant was making her cat act strange. On Monday, she
•
24
hid one plant. On Tuesday, she hid a different plant. She notes how the cat
behaves in the absence of each plant. After the cat has had one day away from
each plant, Suah has discovered which plant is causing her cat to act strangely.
6. QUESTION: Which of the following is the hypothesis in Suah’s experiment?
•
Suah’s pet cat has been acting strangely lately.
•
One of the plants is causing her cat to act strangely.
•
On Monday, she hid one plant.
•
Suah has discovered which plant is causing her cat to act strangely.
Homework (Individual)
Collect the datas from GCLC students regarding the popular songs and
Show with four types of charts. (Line graph, bar graph, pie chart and histogram)
(Flowers , work from home, Calm down, something just like this)
Sample client- 20 students (age- over 10)
Lesson-3 (Using statistics)
What is statistics?
Statistics is the branch of mathematics that deals with collecting,
organizing, analyzing, interpreting, and presenting data.
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In short:
Statistics helps us make sense of numbers and make decisions based on data.
Using statistics
Scientists use statistics to find results and present data. We use statistics in
everyday life, too. They give us information and show us patterns that we may
not otherwise see. You can also use them to support an argument.
This chart uses statistics to show weekly earnings and unemployment rates in
2015.
The chart above shows two sets of statistics. It makes the statistics easy to
understand. In both sets, the categories are people’s educational level. The blue
bars show that people with high school diplomas earn more than people without.
The green bars show there is higher unemployment for people without a high
school diploma. These statistics are useful because they show there are good
reasons to gain your GED, HiSET or TASC diploma!
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Watch a video from Mathematics to see in more detail how to calculate mean,
median, and mode.
https://youtu.be/B1HEzNTGeZ4
TEST TIP: USING STATISTICS TO DESCRIBE DATA
Your science test will require you to use basic statistics. It may present you with an
experiment or other scientific situation. Then it may ask a question that requires
you to calculate the mean. Let’s learn how to understand data in a table and
calculate an answer using the mean.
BACKGROUND: Doctors want to find out if protein supplements help their
patients recovering from knee surgery. A group of 20 patients recovering from
knee surgery is divided into 2 groups of 10 patients each. The 10 patients in Group
1 were given protein supplements. The patients in Group 2 were given no protein
supplements. This table shows how many days each patient in each group took to
recover. When the doctors analyzed the data in this table, they found that their
patients recovered more quickly on average when they were given protein
supplements.
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.
QUESTION: Is the doctors’ conclusion true or false?
Step 1: First let’s make sure we understand what the table is telling us. The column
on the left lists ten numbers. Are these numbers of patients? Number of
supplements? Let’s stop and read the column heading carefully. It says Group 1
(received supplements) number of recovery days. So the numbers in the column
are the numbers of days patients took to recover. The same goes for the righthand column – these are the numbers of recovery days for patients who
did not get the supplements.
Step 2: Now that we understand the data, let’s look at the question. Is it true or
false that the patients recovered more quickly on average with supplements?
What does “on average” mean? It means we need to figure out the average
recovery time of each group to get the answer. We need to calculate the mean.
Step 3: Now that we understand what we are being asked, let’s do the math!
There are 10 patients in each group, so let’s add up Group 1’s recovery days and
divide it by 10: 61 total recovery hours divided by 10 = 6.1 days average. Now let’s
do Group 2: 70 total recovery hours divided by 10 = 7 days average. It seems based
on average recovery time that the answer is true: the supplements did help the
patients to recover more quickly, by almost a whole day on average.
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So your test tips for this lesson are: always read headings and questions carefully,
and learn how to calculate the mean. Then you can answer many questions using
statistics.
WHAT WE LEARNED
•
1
Statistics are sets of numbers that represent information.
•
2
Scientists use statistics to analyze information, provide results and reveal
patterns.
•
3
An average is a number that is typical of a set of range of numbers.
•
4
Mean, median and mode are all kinds of averages.
average
number that is typical of a group of numbers
mean
sum of all the numbers in a set divided by the total number of numbers in that set
median
number in the center of a set of numbers when they are arranged from smallest
to largest
mode
most common number in a set of numbers
sta�s�cs
sets of numbers that represent informa�on and show paterns
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1.QUESTION: What is the mean of the numbers 10, 5, 7, 13, 5?
•
5
•
7
•
8
•
9
2.QUESTION: What is the mode of the numbers 10, 5, 7, 13, 5?
•
5
•
7
•
8
•
9
3.QUESTION: What is the median of the numbers 10, 5, 7, 13, 5?
•
5
•
7
•
8
•
9
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Two scientists are designing instant hot and cold packs for a sports company.
They want to find a chemical that reacts with water to either heat up or cool
down the water inside the packs. They are testing the reaction of ammonium
chloride.
They measure the temperature of the water before they add the ammonium
chloride. After they add the chemical, they measure the temperature again. To
get a good result, they do the test five times. They enter the results in the
following table:
1.QUESTION: What is the average change in water temperature after the reaction
takes place?
•
22.9 degrees
•
22.3 degrees
•
11.7 degrees
•
10.9 degrees
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Lesson-4 (Understanding cells)
What is biology?
Biology is the part of science that studies living things. A scientific word for living
things is organisms. Organisms include plants, animals, and tiny living things too
small to see.
Types of cells
Cells are the microscopic parts that make up all living things. They are able
to reproduce, grow, and create energy.
There are two types of cells: prokaryotic cells and eukaryotic cells.
•
Prokaryotic cells
Bacteria are the smallest and most numerous organisms on the planet.
Bacteria have one cell, and that cell has no nucleus. This simple cell is called
a prokaryotic cell. They multiply constantly by dividing the cell in a process
called binary fission (which means splitting in two).
•
Eukaryotic cells
Eukaryotic cells make plants, animals, and a few other types of living
things. Eukaryotic cells have many different jobs to do. A brain cell in your
body, for example, has an entirely different job than the cell in a leaf that
makes food for the plant.
•
Watch a video about prokaryotic and eukaryotic cells
https://youtu.be/RQ-SMCmWB1s
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The structure of eukaryotic cells
Now let’s look at the structure of cells. All eukaryotic cells are made of the same
basic parts. Here are some of them:
•
The nucleus is the cell’s headquarters. It controls what the cell does and
how it is made.
•
Chromosomes hold the information that tells the cell what it is and how to
behave.
•
Cytoplasm surrounds the nucleus. It holds various smaller parts.
•
Mitochondria (plural of mitochondrion) process oxygen and food to make
energy for the cell.
•
The cell membrane is like a skin. It controls what goes in or out of the cell.
This diagram shows some basic parts of an animal cell.
There are other parts to cells as well as those labelled above. Any parts that have
a function are called organelles. For example, a mitochondrion and a nucleus are
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organelles. Another organelle is a ribosome, which makes protein for the cell to
use.
Plants cells have additional organelles called chloroplasts. Chloroplasts convert
light energy into food for the plant in a process called photosynthesis.
https://docs.google.com/forms/d/e/1FAIpQLSeLgInSunt6ZwZ5hN1yRV628feiBGY
Dv93gzbXX0b9gX_veBA/viewform?usp=header
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TEST TIP: ANSWERING QUESTIONS WITH SCIENTIFIC WORDS
This lesson included many scientific words about cells and cell processes! You don’t
need to remember every part and process. But by the time you take your test, you
should be familiar with scientific words like these. You will have to answer
comprehension (understanding) questions about texts that use scientific words.
The questions will test your thinking skills, not your knowledge!
Let’s practice with a scientific text about mitochondria. Please note: on purpose,
this text has many words and processes you do not know. Do not worry! You are
going to learn the steps for finding an answer in text with very difficult words.
DIRECTIONS: Read the text below from nature.com. Choose the best answer to the
question.
The origin of mitochondria
Mitochondria are thought to have originated from an ancient symbiosis that
resulted when a nucleated cell engulfed an aerobic prokaryote. The engulfed cell
came to rely on the protective environment of the host cell, and, conversely, the
host cell came to rely on the engulfed prokaryote for energy production. Over time,
the descendants of the engulfed prokaryote developed into mitochondria, and the
work of these organelles — using oxygen to create energy — became critical to
eukaryotic evolution.
QUESTION: In the passage above, what organism relied on the protective
environment of the host cell?
A. the ancient symbiosis
B. the descendants
C. the nucleated cell
D. the aerobic prokaryote
When you read the passage, you saw many words you do not know the meaning
of. But the question is using words that are in the text, so after reading the
question carefully, let’s go back and find those words in the text. Here they
are: The engulfed cell came to rely on the protec�ve environment of the host
cell. So we know it was the engulfed cell that relied on the protection.
But “the engulfed cell” is not one of our choices! So we need to figure out which
organism is the engulfed cell. Let’s look at our possible answers and test them
against the text:
35
A. Ancient symbiosis is not an organism, but even if you don’t know that, you can
tell it’s not the right answer because the text doesn’t say it was engulfed.
B. Descendants means the ones that came after, but even if you don’t know that,
you can tell it’s not the right answer because the text doesn’t say they were
engulfed.
C. The nucleated cell – what does the text say about that? It says: A nucleated cell
engulfed an aerobic prokaryote. You may not know what a nucleated cell is, and
you may not know what engulf means, but you can tell the nucleated cell was not
engulfed. It engulfed something else!
D. The aerobic prokaryote – This is our last choice, so let’s check that D is the right
answer. The text says A nucleated cell engulfed an aerobic prokaryote. This tells us
the aerobic prokaryote is the engulfed cell. It is the organism we are looking for. D
is the best answer. (By the way, engulf means surround and swallow up.)
Of course, you may have known the correct answer right away, without testing
each statement. But if you don’t understand the text and don’t know the answer,
use the steps we used here: read the question, then go back to the text to find the
words the question is about. Then test the answers against the text. You will find
the best answer that way.
36
Same structure, different jobs
Although all cells start with the same parts, they take many shapes and perform
many different jobs. The cell we looked at above is a basic animal cell. It could
become a muscle cell, a liver cell, a blood cell, or a nerve cell. It could be inside a
human or a snail. There are more than 250 types of cells in the human body.
Other living things have cells with different functions.
How cells reproduce
In living things, cells are always changing. Every second, cells are dying and new
ones are forming. Two ways that cells reproduce are mitosis and meiosis.
1. Mitosis
Mitosis is the process of cells reproducing themselves. First, the nucleus splits in
two. Then, the cell stretches in the middle until it splits, too. Each nucleus
becomes the center of a new cell. This process is called mitosis. It reproduces the
whole cell, twice, with all the DNA it needs. Your skin cells, blood cells, and
muscle cells reproduce using mitosis.
2. Meiosis
Meiosis happens when a whole organism reproduces itself. A cell splits to create
four new cells, but the new cells have only half the chromosomes of the dividing
cell. After meiosis takes place, one living thing can combine its cells with the cells
of another living thing to create a new being.
Watch a video about meiosis
https://youtu.be/k2DBsovDXxE
37
WHAT WE LEARNED
•
1
Biology is the study of living things, which in science are called organisms.
•
2
Cells are microscopic parts that make up all living things. There are two
types of cells: prokaryotic and eukaryotic.
•
3
Bacteria are the most numerous life form on Earth. They have one simple,
prokaryotic cell.
•
4
Eukaryotic cells take many forms and do different things, but they have the
same basic structure.
•
5
Plant and animal cells reproduce by mitosis or by meiosis.
Guess! What should be? The first letter is given for you.
1. the small part that all living things are made of c_ _ _
2. “skin” that contains the cell and controls what goes in and out
C__ __ __ m _ _ _ _ _ _ _
3. organelles in plant cells that make food for the plant
__
38
c_______
4.threadlike structures that store DNA (the information that tells the cell what it
is and how to behave) c _ _ _ _ _ _ _ _ _ _
5. substance that surrounds the nucleus and holds the smaller organelles
C________
6.ability and power to grow and be ac�ve. Organisms get their energy from food.
E_____
7.cell that has a nucleus and makes up living things – for example, a brain cell
E_ _ _ _ _ _ _ _ _ c_ _
8.process in which one cell divides into four cells, each with half the DNA needed
to reproduce. The other half comes from another organism, for example in sexual
reproduc�on between two animals.
M______
9.organelles in cells that turn sugars into energy that organisms can use
M___________
10. cell division of one cell into two new cells each with a complete set of DNA
M______
11.center of the cell where DNA is stored
n_____ _
12. smaller part inside a cell, including mitochondria and ribosomes
O________
13. anything living, such as a plant, animal, or bacterium o _ _ _ _ _ _ _
14. process by which plants make food from light p _ _ _ _ _ _ _ _ _ _ _ _ _
15. cell with no nucleus, such as the single cell of a bacterium
P_ _ _ _ _ _ _ _ _ c_ _
39
16. make new cells or new living things by mitosis or meiosis r _ _ _ _ _ _ _ _
1.Read this passage of text and answer the question. Use your test tip for
understanding questions about scientific text.
Although cells vary in size, they’re generally quite small. For instance, the
diameter of a typical human red blood cell is about eight micrometers (0.008
millimeters). To give you some context, the head of a pin is about one millimeter
in diameter, so about 125 red blood cells could be lined up in a row across the
head of a pin. With a few exceptions, individual cells cannot be seen with the
naked eye, so scientists must instead use microscopes (micro– = “small”; –scope =
“to look at”) to study them. A microscope is an instrument that magnifies objects
otherwise too small to be seen, producing an image in which the object appears
larger. Most photographs of cells are taken using a microscope, and these
pictures can also be called micrographs.
From the definition above, it might sound like a microscope is just a kind of
magnifying glass. In fact, magnifying glasses do qualify as microscopes; since they
have just one lens, they are called simple microscopes. The fancier instruments
that we typically think of as microscopes are compound microscopes, meaning
that they have multiple lenses. Because of the way these lenses are arranged,
they can bend light to produce a much more magnified image than that of a
magnifying glass.
Question: Based on the information in the test, what meaning does the word
microscope contain? Choose the best answer.
•
Individual cells
•
Looking at small things
•
Making small things bigger
•
Looking through multiple lenses
40
2. It may seem obvious now that we, and other living things, are made up of cells.
Prior to the 1600s, however, it wasn’t obvious at all, for the simple reason that no
one had ever seen a cell up close and personal. To distinguish individual cells in a
piece of tissue or individual bacteria in a sample of liquid required the
development of relatively high-powered microscopes, instruments used for
magnifying objects otherwise too small to be seen. For more on how microscopes
are used in biology today, check out the article on microscopy.
The first person to observe cells as microscopic structures was the British scientist
Robert Hooke. In fact, he was the person who gave cells their name. In his
book Micrographia, he used the term cell to refer to the box-like structures he
saw when he looked at dead cork tissue through a simple microscope. He
chose cell as the name because these boxes reminded him of the cells of a
monastery, the simple rooms in which monks slept.
The cells that Hooke observed, however, were in dead tissue, and were in fact cell
walls left behind after the death of the real cells. The first person to observe
living, moving cells was Anton van Leeuwenhoek, a Dutch shopkeeper and crafter
of lenses. In the 1670s, inspired by Hooke’s book, he began to build his own, more
powerful microscopes. With these, he was able to observe living single-celled
organisms—such as bacteria—and sperm cells, which he collectively called
animalcules.
Question: Which sentence below best describes the main idea in this passage of
text? Choose the best answer.
•
All living things are made of cells.
•
Cells are box like structures
•
The invention of the microscope meant scientists could look at small
things.
•
The invention of the microscope enabled scientists to see cells.
41
Mitochondria are small organelles present in most of the body’s cells which
function in the conversion of certain chemicals in our food, in the presence of
oxygen, to the common currency of energy inside cells (ATP). Mitochondria
contain their own private DNA. In recent years, more than 20 hereditary disorders
have been shown to result from mutations in mitochondrial DNA. Because
mitochondria come only from the egg, most mitochondria-related disorders are
inherited exclusively from the mother. Mitochondrial disorders can appear at any
age in males or females, with a wide variety of non-specific symptoms and signs.
These disorders may cause metabolic disturbances, developmental delay,
blindness, hearing loss, heart rhythm problems, short stature, and gastrointestinal
problems.
QUESTION: Which statement is not made in the paragraph above?
•
Mitochondria are the tiny parts of the body's cells that turn food into
energy.
•
Some mitochondria contain mutations inherited from the mother's
DNA.
•
Mitochondria mutations are only passed down to male children.
•
Mitochondria mutations can cause many disorders.
1.Creates cells that form new parts of organisms, such as skin, blood, etc….
2.Creates complete a new organism such as animals.
3. One cell divides into two cells each with identical DNA.
4. New cell must combine with another cell to reproduce.
5. Produces two whole new cells with complete DNA.
42
6. One cell divides into four cells each with only half the chromosomes of the
dividing cell.
First step of mitosis
second step of mitosis
Third step of mitosis
First step of meiosis
second step of
meiosis
Third step of meiosis
43
Lesson 5: Human Biology
New words
•
Blood Vessels
tubes that carry blood through tissues and organs
•
Cardiovascular
to do with the heart and blood vessels
•
Hormone
chemical substance that sends instructions to cells and tissue
•
Human Biology
the study of how human cells, organs, and systems work
•
Muscle
tissue that provides strength and allows bodies to move
•
Neurons
cells that make up nerves
•
Nutrient
any substance that provides an organism with food for health and growth
•
Organ
self–contained unit, such as the heart, that has an important job to do in
the body
•
Respiratory
to do with breathing
44
•
Skeletal
to do with a skeleton, or bones
•
System
process that follows a set pattern, such as the way organs in your body
work together to keep you alive
•
Tissue
group of similar cells that work together, such as the tissue that makes your
muscles
Human biology
Human biology is the study of how human cells, organs, and systems work. By
themselves, cells are small, but together, they can create many types of tissue.
Tissue makes up organs. Organs make up systems. And systems make up all living
things, including humans!
The following diagram taken from Khan
Academy illustrates the process of muscle
cells combining to form tissues, and tissues
forming organs, and organ systems.
The following diagram taken from Khan
Academy illustrates the process of muscle
cells combining to form tissues, and tissues
forming organs, and organ systems.
45
htps://youtu.be/hn6oxByn1tM
Quiz on Video: Tissues and Organs
1. What is human tissue?
•
a) A chemical substance sends instructions to cells and tissue
•
b) A group of similar cells that work together
•
c) Cells that makeup nerves
•
d) All of the above
2. What are human organs?
•
a) cells that makeup nerves
•
b) self–contained units that have an important job to do in the human
body
•
c) processes that follows a set pattern in your body to keep you alive
•
d) All of the above
46
3. When a question starts with “According to the text..” in the Science portion
of the GED Exam, what can you do to help you find the correct answer?
•
a) Make sure you remember as much as you can about the scientific
subject
•
b) Have as much scientific vocabulary already memorized
•
c) Make a random guess
•
d) Read the text carefully and quickly test each answer choice based on
the passage
Skeletal & Muscular System
Two or more organs working together to do a specific function are called a
system. The human body is made up of many systems. Here is some information
about important systems in the human body.
Skeletal system
Image courtesy of interac�ve–biology. Com
Humans have 206 bones that make their
skeleton. Bones are alive, just like all the other
parts of your body! There is also a network of
tendons, ligaments, and cartilage connecting the
skeleton. All these parts together form the
skeletal system. The skeletal system supports
the body, and it is essential for movement. An
Orthopedist is a doctor who specializes in the
musculoskeletal system.
47
Muscular system
Muscles allow us to move. They attach to our
bones. The muscular system provides strength,
balance, posture, movement, and heat. The
muscles that power the heart work
automatically. Otherwise, we would think
about each breath we take! An Orthopedist is a
doctor who specializes in the musculoskeletal
system.
Respiratory system
The respiratory system is all the organs and tissues that get oxygen to your
tissues. Your cells need oxygen to live. When you inhale (breathe air in) your lungs
take in oxygen for your body. When you exhale (breathe air out) your lungs get rid
of carbon dioxide.
A Pulmonologist is a physician who specializes in the respiratory system.
These are the lungs of a non–smoker
and a smoker. Cigarete smoke hurts the
lungs. So does living in places with a lot
of air pollu�on.
48
Cardiovascular system
The cardiovascular system carries
oxygen and nutrients around the
body. It also removes waste. It uses
blood in a system of blood
vessels (veins and arteries) to do this.
The major organ of the circulatory
system is the heart. The heart drives
this system. First, it pumps blood to
the lungs to pick up oxygen and leaves
carbon dioxide behind. Then the heart
pumps blood through the body. The
blood gives oxygen to cells and picks
up carbon dioxide. The blood finally
returns to the heart to begin its cycle
again. Blood travels through the blood
vessels from large arteries, to smaller
arteries, to capillaries, to small veins,
to large veins, and back to the heart.
A cardiologist is a doctor who
specializes in treating diseases of the
cardiovascular system — mainly the
heart and blood vessels.
49
Digestive system
The digestive system consists of the mouth, esophagus, stomach, small intestines,
and large intestines. The digestive system breaks down food into nutrients, which
the body uses for energy.
Diagram of the human diges�ve
system
Here are the parts of the diges�ve system:
•
•
•
•
•
The gastrointes�nal (GI) tract includes the large intes�ne, the small
intes�ne, and the esophagus. It carries food through the body. It sends
nutrients to the bloodstream and gets rid of waste.
The liver does three main things: it aids in diges�on, makes proteins, and
gets rid of bad things.
The pancreas helps break down food into nutrients.
The gallbladder helps digest fat.
A Gastroenterologist is a doctor specializing in diges�ve problems that
affect your diges�ve system, which includes your esophagus, stomach,
intes�nes, pancreas, gallbladder, and liver.
50
Urinary system
The urinary system gets rid of unwanted materials from your body. These include
materials left after other systems have taken out the nutrients. The organs in the
urinary system include the liver, the kidneys, the large intestine, the bladder, and
the skin.
A urologist is a doctor who specializes in disorders of the urinary system.
Endocrine system
The endocrine system mostly deals with processes that happen slowly, such as
developing bones. The endocrine system uses hormones to send messages all
over the body. Hormones help to control:
•
•
•
•
•
•
mood
growth and development
�ssue func�on
metabolism
sexual func�on
reproduc�on
Endocrinologists are medical doctors who specialize in diagnosing and treating
health conditions related to problems with the body's hormones, hormonal
glands, and related tissues.
51
Nervous system
The brain is the control center of the nervous system. This is where thoughts,
feelings, and memories reside. The nervous system is made up of billions of nerve
cells, or neurons, which join together to make nerves. Nerves constantly send
signals back and forth between the brain and the rest of the body.
The signals are messages that
control your body’s actions.
Some actions are voluntary
(things you decide to do) and
some are involuntary (things
your body does automatically).
A Neurologist is a doctor who
treats diseases of the brain and
spinal cord, peripheral nerves,
and muscles.
Immune System
The immune system protects the body. There are many bacteria, viruses, and
other organisms that can harm us. The immune system is a network of cells,
tissues, and organs that work together to attack any invaders! It is what keeps us
healthy. People with weak immune systems can get very sick from things that
would not affect someone with a strong immune system.
52
The human immune system is
made up of organs, cells, and
proteins that work together
to protect the body from
invaders.
An Immunologist is a doctor
who specializes in disorders
of the immune system.
Video: Systems in the Body
htps://youtu.be/Ae4MadKPJC0
Quiz on Video: Systems in the Body
1.Which of the following is a human biological system?
•
a) Skeletal
•
b) Muscular
•
c) Nervous
•
d) All of the above
53
2. Which of the following is a job of the human cardiovascular system?
•
a) To deliver oxygen
•
b) To pump blood
•
c) To deliver nutrients throughout the body
•
d) All of the above
3.What is the main job of the human nervous system?
•
a) To be the communication network of nerve cells
•
b) To physically protect organs and tissues
•
c) To hold the body together with over 200 bones
•
d) All of the above
What we learned
1. Human biology is the study of how human cells, organs, and systems work.
2. Human cells of the same type form groups to make tissue.
3. The four types of tissue in animals are: connective, muscle, nervous, and
epithelial.
4. Tissues form organs, which are self–contained units such as the brain,
heart, liver, and lungs.
5. The human body has many important systems, such as the muscular system
and the immune system.
54
Final Quiz: Human Biology
Read this passage of text. Then answer the question using your test tip about
testing statements against the data.
Multicellular organisms
Most cells in large multicellular organisms don’t directly exchange substances like
nutrients and wastes with the external environment. Instead, they are
surrounded by an internal environment of extracellular fluid—literally, fluid
outside of cells. The cells get oxygen and nutrients from this extracellular fluid and
release waste products into it. Humans and other complex organisms have
specialized systems that maintain the internal environment, keeping it steady and
able to provide for the needs of the cells.
QUESTION: Based on this passage of text, is the following statement true or false?
1. The majority of cells in a large living thing are in direct contact with
the outside environment.
•
True
•
False
Read this passage of text from your last quiz. Then answer the question using
your test tip about testing statements against the data.
Microscopes and lenses
Although cells vary in size, they’re generally quite small. For instance, the
diameter of a typical human red blood cell is about eight micrometers (0.008
millimeters). To give you some context, the head of a pin is about one millimeter
in diameter, so about 125 red blood cells could be lined up in a row across the
head of a pin. With a few exceptions, individual cells cannot be seen with the
55
naked eye, so scientists must instead use microscopes (micro– = “small”; –scope =
“to look at”) to study them. A microscope is an instrument that magnifies objects
otherwise too small to be seen, producing an image in which the object appears
larger. Most photographs of cells are taken using a microscope, and these
pictures can also be called micrographs.
From the definition above, it might sound like a microscope is just a kind of
magnifying glass. In fact, magnifying glasses do qualify as microscopes; since they
have just one lens, they are called simple microscopes. The fancier instruments
that we typically think of as microscopes are compound microscopes, meaning
that they have multiple lenses. Because of the way these lenses are arranged,
they can bend light to produce a much more magnified image than that of a
magnifying glass.
2. Based on the information in the text, which of these statements is
true?
Choose the best answer.
•
a) Magnifying glasses are a type of microscope.
•
b) Microscopes must have multiple lenses.
•
c) Micrographs are a type of microscope.
•
d) Microscopes must show cells.
Read this passage of text and answer the question.
“Discovering cells:
It may seem obvious now that we, and other living things, are made up of cells.
Prior to the 1600s, however, it wasn’t obvious at all, for the simple reason that no
one had ever seen a cell up close and personal. To distinguish individual cells in a
piece of tissue or individual bacteria in a sample of liquid required the
development of relatively high–powered microscopes, instruments used for
magnifying objects otherwise too small to be seen. For more on how microscopes
are used in biology today, check out the article on microscopy.
56
The first person to observe cells as microscopic structures was the British scientist
Robert Hooke. In fact, he was the person who gave cells their name. In his book
Micrographia, he used the term cell to refer to the box–like structures he saw
when he looked at dead cork tissue through a simple microscope. He chose the
cell as the name because these boxes reminded him of the cells of a monastery,
the simple rooms in which monks slept.
The cells that Hooke observed, however, were in dead tissue, and were in fact cell
walls left behind after the death of the real cells. The first person to observe
living, moving cells was Anton van Leeuwenhoek, a Dutch shopkeeper and crafter
of lenses. In the 1670s, inspired by Hooke’s book, he began to build his own, more
powerful microscopes. With these, he was able to observe living single–celled
organisms—such as bacteria—and sperm cells, which he collectively called
animalcules.”
3. Why did Anton van Leeuwenhoek begin to build more powerful
microscopes?
•
a) Because he wanted to see cells move.
•
b) Because he wanted to collect animalcules.
•
c) Because he had read “Micrographia” by Robert Hooke.
•
d) Because he wanted to sell microscopes in his shop.
4. A urologist is a doctor who specializes in disorders of the urinary
system. Which of the following patients is the most likely to be treated by a
urologist?
•
a) A patient with low levels of iron in her blood
•
b) A patient with a painful kidney stone
•
c) A patient with swollen veins in the anus called hemorrhoids
•
d) A patient with chronic indigest
57
•
Lesson 6: (DNA, Genes, and Heredity)
New Words
•
Allele
version of a gene
•
Chromosome
unit in the nucleus of a cell that contains strands of DNA
•
Dominant
stronger one of two genes
•
DNA
set of instructions inside the nucleus of every cell
•
Gene
the unique recipe, or sequence of DNA
•
Gene-specific
sequence or pattern of DNA
•
Genome
complete set of DNA that makes an organism what it is
•
Helix
something shaped like a corkscrew or spiral staircase
•
Heredity
a process by which living things inherit characteristics
58
•
Organism
a living thing, such as a plant, animal or person
•
Recessive
not expressed gene of the two genes
•
RNA
the messenger that carries DNA inside a cell
•
Trait
something you would notice about a person: it could be physical, like hair
color, or a personal quality, such as a cheerful nature
DNA, or deoxyribonucleic acid, is the molecule that carries the genetic
instructions for living organisms. It is often described as a blueprint or recipe for
building and maintaining life.
How do cells decide whether to be a brain
cell, muscle cell, or skin cell?
DNA has a double-helix structure,
DNA (short for Deoxyribonucleic acid) tells
the cell what to be and do.
called a double helix.
Inside the cell’s nucleus are strands of
DNA. The DNA holds instructions, like
recipes, for the cell. The strands look like
two spiral ladders twisted together. This is
DNA makes new cells
59
The DNA tells the cell what to be and do, but it also tells it how to make more
cells just like itself. To do this, a DNA strand gives its information to a messenger
strand called RNA.
The RNA strand carries the “recipe” out of the nucleus to the ribosomes. Using
the recipe, the ribosomes build proteins in just the right shape for their particular
kind of cell.
This diagram shows what happens inside a cell to make it grow and do its job. It
shows how information is taken from DNA inside the nucleus and turned into
proteins. The red line is the messenger RNA (mRNA). The green pentagon is the
ribosome. The dark blue circles are the building blocks of proteins (amino acid
monomers) linked together from the information in the DNA. The proteins make
the parts of cells, and cells are the tiny parts that all living things are made of!
60
What are Genes?
We just learned that each DNA recipe makes one kind of protein. The unique
recipe, or sequence of DNA, is called a gene.
Genes can make all kinds of proteins. Some proteins make hormones that affect
how we feel. Other proteins create cell structures or make things happen in our
bodies.
Genes give us traits
Genes also give people their traits. Traits are characteristics: things as hair color
and height. But traits include tendencies, too. A tendency is something like
whether you are mostly cheerful or easily depressed. Or it could be that you are
more likely to put on weight than your friend who has different genes.
61
Chromosomes
Genes (strands of DNA in a particular pattern) are stored in chromosomes.
Chromosomes contain hundreds or even thousands of genes.
Chromosomes form genomes
A genome is a complete set of DNA for any organism or living thing. The human
genome has 23 pairs of chromosomes. That makes 46 chromosomes. One set of
23 chromosomes comes from your mother, and one set comes from your father.
DNA makes sequences called genes. Genes are stored in packets called
chromosomes. Every genome is made of a set number of chromosomes. This is
the human genome: 23 pairs of chromosomes.
One special pair of chromosomes decides what
sex you are. Females always have two X
chromosomes, so they always give an X to their
child. Males always have one X and one Y. This
means the father can give either an X or a Y to a
child. That X or Y decides the sex of the child.
62
How Heredity Works
We learned that genes give us our traits, such as hair color. We also learned that
we get our genes from our parents. So our traits come from our parents. This is
why children look like their parents. We call this heredity.
But what if a father has black straight hair while the mother has brown curly hair?
If their children all have brown curly hair, the mother’s hair gene is most
likely dominant. It was the stronger one. The father’s black hair gene was most
likely the recessive gene – it stayed in the background. For a person to inherit
black hair in this case, they would have to inherit two recessive alleles or genes
for that trait.
63
Heredity Experiment
In 1865, a scientist named Gregor Mendel used an experiment to show how
heredity and dominant genes work.
Mendel used peas for his experiment. Just like people, peas get one copy of DNA
from each parent pea! Peas can be green (G) or yellow (Y). A pea with two yellow
genes (YY) is yellow, and a pea with two green genes (GG) is green. But what
happens if a pea is YG? One of the genes is dominant. The dominant gene controls
whether it is green or yellow.
Let’s look at this in a diagram.
This diagram shows the genetics of peas. Allele means the gene version the pea
has. Look at how the YG in the second row can produce YYs, YGs, or GGs.
In the diagram above, Y is dominant, so peas with both a Y and G are yellow. If a
YY pea breeds with a GG pea, the first generation of their offspring is all YG
because they get one copy from each. But in later generations, there are other
possibilities. This is because sometimes the G is passed on from a YG pea. That
means a pea that looks yellow is passing on its green allele. If that green pairs
with another green, then it is a GG and will produce a green pea.
Before the discovery of genetics, people were confused as to how a green pea
could come from yellow pea parents!
64
Watch this video to learn more about genetics research.
https://youtu.be/v8tJGlicgp8
Quiz on Video: Genetics Research
1.What does genetics study?
•
a) How traits are passed down from one generation to the next
generation
•
b) The process of heredity
•
c) The expression of human traits
•
d) All of the above
2. What is the human collection of genes called?
•
a) Genome
•
b) RNA
•
c) Helix
•
d) Recessive
3.What international project identified about 99% of the human genetic
sequence at the turn of the 21st century?
•
a) The International RNA Project
•
b) The Human Chromosome Project
•
c) The Human Genome Project
•
d) All of the above
65
Video: Punnett Squares
https://youtu.be/HaPR9sPT4ys
Quiz on Video: Punnett Squares
1. What is a Punnett square?
•
a) A diagram used to predict a particular genotype
•
b) An approach named after Reginald Punnett who devised the
approach
•
c) A diagram used by biologists to determine the probability of offspring
having a particular genotype
•
d) All of the above
2. Brown eyes (B) are genetically dominant over blue eyes (b). If Amelia has a
brown-eye gene and a blue-eye gene (Bb), what color eyes does Amelia have?
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a) Brown
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b) Blue
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c) Green
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d) Hazel
3.Which of the following is true about the Punnett square diagram?
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a) It is best for predicting complex genetic inheritance with great
accuracy.
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b) It is highly precise for predicting random variations and outcomes
observed in small samples and individual families.
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c) It is highly effective in estimating exact distribution of genotypes and
phenotypes when there is a linkage between two genes.
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d) It is a useful model for understanding the basics of how meiosis and
fertilization result in various possible genotypes and phenotypes of
offspring.
GED Exam Tip
General Ideas to Keep in Mind for Testing
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Many science questions are analyzing the text, diagram, or image given.
Use trends to make predictions on a data set
Look at the answers before reading the text to narrow down the options
and eliminate those that do not have the correct characteristics.
When you need to use the computer for the GED Science test, a calculator
symbol with the word calculator will appear on the toolbar at the top of
your screen. Click on it to open the online calculator. You may be familiar
with it from the GED Math test.
20% of the questions will cover Earth & Space Science, 40% are on physical
science, and 40% are on life science.
There is no penalty for getting a wrong answer on the test. You select at the
top of the computer screen “Flag for Review” any question you want to
think about, then come back to it. Be sure to watch your time.
You could also eliminate choices then make a guess if needed.
Be sure to read the titles and labels on diagrams and graphs to help you
answer questions.
Take as many practice tests as you like to experience the types of questions
and to better prepare you for the actual GED Science test.
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What we learned
1. DNA is a set of instructions inside every cell.
2. RNA is a messenger that carries DNA code inside the cell.
3. Chromosomes are many pairs of genes, with one of each pair inherited
from each parent.
4. Genes are sequences of DNA.
5. Heredity is the process by which living things pass their DNA to their
descendants.
6. The complete set of human DNA (or genome) is contained in 23 pairs of
chromosomes, with one chromosome in each pair inherited from the
mother and one from the father.
Final Quiz: DNA, Genes, and Heredity
A green-eyed mother and a brown-eyed father are expecting a child. Brown
(B) is a dominant gene and green (b) is a recessive gene.
1. What possible
combination for their
offspring belongs in the
empty square?
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a) Bb
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b) bB
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c) BB
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d) bb
2.What are the chances that the child will have the same eye color as the
mother?
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a) 0%
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b) 25%
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c) 50%
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d) 75%
An apple tree with red apples (Aa) has a dominant red–apple gene (A) and a
recessive yellow–apple gene (a). It is crossed with another apple tree with the
same traits (Aa).
3.What is the chance that the trees’ offspring will have yellow apples?
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a) 0%
c) 25%
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b) 5%
d) 50%
4. Add the appropriate number in the blank below
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In order to show a recessive trait, an organism must inherit ____________
recessive alleles for that trait.
a) 1
c) 3
b) 2
d) 4
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