Cells make up all living things, including your own body. The image below
shows a group of cells. Not all cells look alike. Cells can differ in shape and sizes.
And the different shapes usually mean they do different things.
A cell is the smallest structural and functional unit of an organism. Some
organisms, like bacteria, consist of only one cell. Large organisms, like humans,
consist of trillions of cells. Compare a human to a banana. On the outside, they
look very different, but if you look close enough you’ll see that their cells are
actually very similar.
Question 1
1.
__________make up all living things.
Question 2
2.
Question 3
3.
Question 4
4.
__________organisms like bacteria are composed of just one cell,
whereas __________ organisms can be composed of trillions of cells.
Cells have many organelles that perform specific tasks to help the cell survive. Even very different types of cells have many of the same organelles. Just like your body parts, it is important for a cell's organelles to work together. Click on the two organelles labeled in the animal cell below to learn more.
Question 5
5.
An__________is a structure inside the cell that performs a specific function to help the cell survive. The__________acts as the control center of the cell, directing its activities. The
__________separates the cell from its surroundings.
Question 6
6.
Question 7
7.
Question 8
8.
Place each of the terms below into the correct part of the Venn diagram.
Other Answer Choices:
in an animal cell
stores chromosomes
allows food to enter the cell
Question 9
9.
Place each of the terms below into the correct part of the Venn diagram.
Other Answer Choices:
sends food out of the cell
controls activities inside the cell
is an organelle
Question 10
10.
The__________cushions organelles and gives the cell structure. The__________
breaks down materials and stores food and water for the cell. The__________
is like a power plant, making energy for the cell.
Question 11
11.
Question 12
12.
Question 13
13.
Question 14
14.
Drag each of the labels below to the correct organelle.
Other Answer Choices:
nucleus
cell membrane
cytoplasm
mitochondria
vacuole
Check for Understanding:
The cell's organelles perform specific functions to help the cell survive.
1. The cell membrane separates the cell from its surroundings and gives the cell shape. It also acts as a gatekeeper, controlling what enters and leaves the cell.
2. The nucleus controls the activities in the cell and stores the cell's DNA.
3. The vacuole stores water for the cell.
4. The mitochondria turn food (sugars) and oxygen into energy for the cell.
5. The cytoplasm is a jelly-like material that fills the cell, separating the organelles and giving the cell shape.
Because plants have different needs from animals, their cells have two extra organelles. Click on the buttons below to learn more.
Question 15
15.
The plant's__________gives the plant extra structure and support. The__________
captures sunlight and turns it into sugars for the plant to use for energy.
Question 16
16.
Question 17
17.
Question 18
18.
Drag each of the labels below to the correct organelle.
Other Answer Choices:
vacuole
mitochondria
cell wall
chloroplast
cell membrane
Check for Understanding:
Because plants have different needs from animals, their cells have two extra organelles.
1. The cell wall surrounds the cell membrane, giving plant cells extra structure and protection. Plants do not have bones, so they need stiff cell walls to hold them up.
2. The chloroplast captures sunlight like a solar panel and turns it into sugar that the plant can use to make energy. Plants are green because their chloroplasts contain a green pigment called chlorophyll.
Question 19
19.
Question 20
20.
Question 21
21.
Question 22
22.
Question 23
23.
Question 24
24.
Question 25
25.
Question 26
26.
Question 27
27.
Question 28
28.
The nucleus controls the functions of the cell. Its instructions are contained in a chemical called__________that is stored in the nucleus in a structure called__________.
Question 29
29.
Question 30
30.
Question 31
31.
Question 32
32.
Most cells are so small that you cannot see them without the help of a
microscope. It was not until 1665 that English scientist Robert Hooke invented a
basic light microscope and observed cells for the first time, by looking at a piece
of cork, which he got from a tree. You may use light microscopes in the
classroom. You can use a light microscope to see cells like the image below.
In 1858, after using microscopes much better than Hooke’s first microscope,
Rudolf Virchow developed the hypothesis that cells only come from other cells.
For example, bacteria, which are single-celled organisms, divide in half (after
they grow some) to make new bacteria. In the same way, your body makes new
cells by dividing the cells you already have. In all cases, cells only come from
cells that have existed before. This idea led to the development of one of the
most important theories in biology, the cell theory.
Cell theory states that:
1. All organisms are composed of cells.
2. Cells are alive and the basic living units of organization in all
organisms.
3. All cells come from other cells.
As with other scientific theories, many hundreds, if not thousands, of experiments
support the cell theory. Since Virchow created the theory, no evidence has ever
been identified to contradict it.
Who came up with the first microscope?
Albert Einstein
Robert Hooke
Rudolf Virchow
Which of these NOT part of cell theory? (choose 2)
Cells can be born
All cells come from other cells
Cells are alive and the basic living units of organization in all
organisms
Cells never die
All organisms are composed of cells
Single-celled (unicellular) organisms like bacteria are composed of just one cell,
whereas multicellular organisms can be composed of trillions of cells.
Multicellular organisms include protists (though single-celled protists also exist),
fungi, plants and animals. Most plant and animal cells are between 1 and 100 μm
(micrometer) in size and therefore can only be observed under the microscope.
The one cell of a unicellular organism must be able to perform all the functions
necessary for life. These functions include metabolism, homeostasis, and
reproduction. Specifically, these single cells must transport materials, obtain and
use energy, dispose of wastes, and continuously respond to their environment.
The cells of a multicellular organism also perform these functions, but they may
do so in collaboration with other cells.
Although cells share many of the same features and structures, they also can be
very different. Each cell in your body is designed for a specific task. In other
words, the cell's function is partly based on the cell's structure. For example:
● Red blood cells are shaped with a pocket that traps oxygen and brings
it to other body cells. These cells also have a large surface area that
aids in oxygen transfer.
● Nerve cells are long and stringy in order to form a line of
communication with other nerve cells, like a wire. Because of this
shape, they can quickly send signals, such as the feeling of touching a
hot stove, to your brain.
● Skin cells are flat and fit tightly together to protect your body.
As you can see in the images below, cells are shaped in ways that help them do
their jobs. Multicellular (many-celled) organisms have many types of specialized
cells in their bodies.
Which of the following is NOT functions of the organelle identified in this picture?
gives the cell shape and support
controls the cell's functions
controls what enters and leaves the cell
separates the cell from its surroundings
Which of the following are functions of the organelle identified in this picture? (choose 2)
makes energy for the cell
allows water to enter the cell
stores DNA as chromosomes
controls the cell's functions
Which of the following is/are functions(s) of the organelle identified in this picture?
cushions the organelles
stores water
lets things in and out of the cell
makes energy for the cell
Which of the following is/are functions(s) of the organelle identified in this picture?
cushions organelles
separates the cell from its surroundings
makes energy for the cell
Which of the following is/are functions(s) of the organelle identified in this picture?
stores water
stores food
makes energy for the cell
breaks down materials
Which of the following are functions of the organelle identified in this picture? (choose 2)
gives extra structure and support to the plant
provides extra protection
allows waste to pass out of the cell
transports materials into the cell
Which of the following are functions of the organelle identified in this picture?
makes sugars (food) into energy for the cell
turns sunlight into sugars (food)
gives extra structure and support to the plant
provides extra protection
An organelle is __________.
another term for the nucleus and the cytoplasm
a structure within a cell that performs a function to help the cell survive
an animal cell structure that performs a function to help the cell survive
one of the body's smaller organs
The cell membrane __________.
cushions the organelles within the cell
helps plants stand upright without bones
separates the cell from its surroundings and gives the cell its shape
protects plant cells from predators
The nucleus __________.
captures energy from the Sun in plant cells
cushions and separates the cell's organelles
makes food for the cell
controls the activities occurring in the cell
The vacuole __________.
breaks down materials and stores food and water
makes food for the cell
turns sunlight into food for the cell
makes energy in animal cells and stores food in plant cells
The mitochondrion __________.
turns sunlight into energy for the cell
controls what comes into and leaves the cell
stores energy for the cell
turns oxygen and sugars into energy for the cell
The cytoplasm is __________.
an organelle found only in plant cells that gives the cell structure
an organelle that breaks down food so that it can be turned into energy
a jelly-like material that fills the cell, separating the organelles and giving the cell shape
an organelle that carries food into the cell
The cell wall __________.
surrounds the cell membrane, giving plant cells and other organisms extra structure and protection
prevents plant cells from allowing water into their cells from the surroundings
is a type of bone that helps plants stay upright
is a common animal cell organelle that makes hard layers, like a turtle's shell
The chloroplast __________.
removes waste from the cell
sends energy out of the cell to the surroundings
stores the energy from sunlight in sugars
turns sugars into energy the plant cell can use
How are cell membranes and cell walls different?
Animal cells do not have cell walls, while plant cells do.
Cell walls make plant cells green.
Cell walls are more common in human cells than cell membranes.
Cell walls make a cell stiffer than cell membranes.
The definitions of which two organelles should be swapped?
•Nucleus: directs the cell's activities
•Mitochondrion: turns light energy into sugar (food)
•Chloroplast: turns food into energy for the cell
•Vacuole: breaks down materials and stores food and
mitochondrion and chloroplast
chloroplast and vacuole
vacuole and mitochondrion
nucleus and mitochondrion
Which of the following organelles is NOT being pointed to in this image?
cell wall
nucleus
cell membrane
Which of the following organelles are in plant cells but NOT animal cells?
Check all that are true.
cell wall
chloroplast
cell membrane
mitochondria
Imagine an amoeba needs to store excess water. What organelle might do this?
