BIOLOGY

REVISION SHEET

FINAL EXAM

TERM-I

GRADE 9

Academic Year: 2020 - 2021

Note: The students should first study from their textbook and then try to solve this revision sheet independently

Materials included in the FINAL exam:

Chapter 3

Sections: 1,2,3,4 & 5

Textbook Pages: 70-91

Student Name: ………………………………………………………..

SECTION 3.1

Q.1: Match each scientist in the table with the statement listed below that describes what

he did to help develop the cell theory.

a. concluded that animals and, in fact, all living things are made of cells.

b. was the first to identify cells and name them.

c. proposed that all cells come from other cells.

d. concluded that plants are made of cells.

e. observed live cells and observed greater detail.

Q.2: Compare between Eukaryotic and Prokaryotic cells:

Eukaryotic Cells Prokaryotic Cells

Nucleus

Membrane-bond organelles

Place of DNA

Cell type

Q.3: What are the three parts of the cell theory?

_______________________________________________________________________

_______________________________________________________________________

_______________________________________________________________________

Scientist Letter of Statement that Completes the Sentence

1. Hooke

2. Leeuwenhoek

3. Schleiden

4. Schwann

5. Virchow

SECTION 3.2

Q.1: Write the function of each cell organelles and describe its structure:

1) Nucleus 2) Endoplasmic Reticulum

3) Vacuole

4) Cytoplasm

5) Golgi Apparatus 6) Lysosomes

7) Cell membrane 8) Ribosomes

9) Cytoskeleton 10) Vesicles

11) Mitochondria

12) Cell Wall 13) Chloroplasts

Q.2: Answer the following questions:

a) What characteristics are shared by most cells?

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

b) What are the main differences between animal and plant cell?

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

c) What similarities do mitochondria and chloroplasts share?

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

d) What is the difference between a cell wall and a cell membrane?

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

SECTION 3.3

MAIN IDEA: Cell membranes are composed of two phospholipid layers.

Q.1: Draw a phospholipid in the box below. Label the three major parts.

2. Which part of a phospholipid is charged, or polar?

______________________________________________________________

3. Which part of a phospholipid is nonpolar?

______________________________________________________________

4. What type of molecules interact with water, polar or nonpolar?

______________________________________________________________

5. Where does a cell membrane come into contact with water?

______________________________________________________________

6. Why do the phospholipids surrounding the cell form a bilayer?

______________________________________________________________

MAIN IDEA: A cell membrane has other types of molecules embedded in the phospholipid bilayer.

Q.2: List a function of each type of molecule in the table below.

Molecule Function

7. Cholesterol

8. Proteins

9. Carbohydrates

Q.3: Fill in the blanks:

10. A ________________ detects a signal molecule and carries out an action in response.

11. A ________________ is a molecule that acts as a signal when it binds to

a receptor.

12. A ligand that can cross the cell membrane can bind to an ________________ receptor.

13. A ligand that cannot cross the cell membrane can send a message to a cell by binding to a

_____________ receptor, which then _____________ shape.

Q.4: Answer the following questions:

16. The cell membrane allows some, but not all, molecules to cross. What term describes this

property?

______________________________________________________________

17. How do intracellular receptors differ from membrane receptor?

______________________________________________________________

______________________________________________________________

______________________________________________________________

SECTION 3.4 AND 3.5

Q.1: Complete the concept map below about passive transport:

Q.2: Answer the following questions:

a. What is a concentration gradient?

______________________________________________________________

b. What does it mean for a molecule to diffuse down a concentration gradient?

______________________________________________________________

c. What does it mean for a molecule to diffuse against a concentration gradient?

______________________________________________________________

Transport across cell membrane

.......................

Moves ...................

concentration gradient

From ...............

concentration to ................. concentration

includes:

Endocytosis

..................

..................

.......................

Moves ...................

concentration gradient

From .................

concentration to .................. concentration

Diffsion

Example: .......................

Isotonic

..................

...................

.......................

occurs by the help of

...........................

d. Which solution has the highest concentration of particles?

______________________________________________________________

f. Which solution has the lowest concentration of particles?

______________________________________________________________

h. So, The higher the concentration of dissolved particles in a solution, the

______________ the concentration of water molecules in that solution.

Q.3: Complete the Y diagram below to compare and contrast the processes of endocytosis

and exocytosis. Under the heading “endocytosis,” list the characteristics of endocytosis.

Under the heading “exocytosis,” list the characteristics of exocytosis. At the bottom of the Y,

write the characteristics that both processes have in common. Then lightly cross out those

characteristics at the top of the Y.

Endocytosis

Exocytosis

Both

Answer Key

SECTION 3.1

Q.1: Match each scientist in the table with the statement listed below that describes what

he did to help develop the cell theory.

Q.2: Compare between Eukaryotic and Prokaryotic cells:

Eukaryotic Cells Prokaryotic Cells

Nucleus ×

Membrane-bond organelles ×

Place of DNA Nucleus Cytoplasm

Cell type Animal and

plant cell

Bacteria

Q.3: What are the three parts of the cell theory?

ALL ORGANISMS ARE MADE OF CELLS.

ALL EXISTING CELLS ARE PRODUCED BY OTHER LIVING CELLS.

THE CELL IS THE MOST BASIC UNIT OF LIFE

Scientist Letter of Statement that Completes the Sentence

1. Hooke B

2. Leeuwenhoek E

3. Schleiden D

4. Schwann A

5. Virchow C

SECTION 3.2

Q.1: Write the function of each cell organelles and describe its structure:

1) Nucleus

The nucleus is a large structure

inside the cell. It Controls activities

in the cell and reproduction of the

cell. It’s center

Contains deoxyribonucleic acid or

DNA, which determines traits that

are passed on to new generations

when a cell reproduces.

2) Endoplasmic Reticulum

The Endoplasmic Reticulum consists

of folded membranes that act as

channels to transport proteins and

Other materials through the

cytoplasm.

3) Vacuole

Structures that temporarily store

water, other substances, and wastes

in cells. Vacuoles in plant cells are

usually much larger than those in

animal cells.

4) Cytoplasm

The cytoplasm is a gel-like fluid

inside the cell. It contains water,

other substances, and all the cell

organelles.

5) Golgi Apparatus

receives proteins from the

endoplasmic reticulum, sorts them,

Modifies some of them, and

packages them into little bag-like

structures called vesicles, which

break off of the structure and go into

the cytoplasm.

6) Lysosomes

Lysosomes contain digestive

chemicals like enzymes, which break

down and recycle worn-out

organelles.

7) Cell membrane

A layer that protects and surrounds

cells. It controls substances that flow

in and out of the cell.

8) Ribosomes

Ribosomes are organelles that

assemble or produce molecules

called proteins in the cell.

9) Cytoskeleton

The cytoskeleton is a structure that

helps cells maintain their shape and

internal organization, and it also

provides mechanical support that

enables cells to carry out essential

functions like division

and movement

10) Vesicles

Membrane covered structures that

carry proteins, water, and Nutrients

around the cell and even in and out of

the cell.

11) Mitochondria

In this organelle, the cell produces

energy using the process of cellular

respiration: glucose + oxygen 🡪

carbon dioxide + water + energy

12) Cell Wall

A cell wall is a tough layer outside the

cell membrane. It can be rigid, which

helps a plant hold its shape. It also

protects the inside of the cell.

13) Chloroplasts

In chloroplasts, the process of

photosynthesis is carried out.

Photosynthesis uses energy from the

sun to convert carbon dioxide and

water into sugar and oxygen. In this

way, plant cells produce food.

Q.2: Answer the following questions:

a) What characteristics are shared by most cells?

Most cells have membrane bound organelles and a nucleus. Most cells contain cytoplasm, are enclosed by a membrane, and have a nucleus. Most cells are microscopic, enclosed by a membrane, and contain cytoplasm.

b) What are the main differences between animal and plant cell?

A plant cell contains a large, singular vacuole that is used for storage and maintaining

the shape of the cell.

In contrast, animal cells have many, smaller vacuoles.

Plant cells have a cell wall, as well as a cell membrane. ... Animal cells simply have a cell membrane, but no cell wall

c) What similarities do mitochondria and chloroplasts share?

Chloroplasts, like mitochondria, produce energy for plant cells.

Both mitochondria and chloroplasts have their own circular DNA and can function independently of the eukaryotic host cell

d) What is the difference between a cell wall and a cell membrane?

Cell membrane helps to enclose the cell organelles and cytosol inside a cell. A cell wall is a ridged, protective layer and it covers the cell membrane.

For plants, cell walls are mainly made up of cellulose, while a cell wall in bacteria is made up of peptidoglycan, and for fungi it is made up of chitin.

SECTION 3.3 MAIN IDEA: Cell membranes are composed of two phospholipid layers.

Q.1: Draw a phospholipid in the box below. Label the three major parts.

2. Which part of a phospholipid is charged, or polar?

Phosphate ____________________________________________________

3. Which part of a phospholipid is nonpolar?

Fatty acid _____________________________________________________

4. What type of molecules interact with water, polar or nonpolar?

polar _________________________________________________________

5. Where does a cell membrane come into contact with water?

On both the inner and outer sides as the cytoplasm is full of water, and the

surrounding of any living cell should be water or it dies

6.Why do the phospholipids surrounding the cell form a bilayer?

Because the properties of polar heads and nonpolar tails cause the phospholipids to arrange themselves in layers

MAIN IDEA: A cell membrane has other types of molecules embedded in the phospholipid bilayer.

Q.2: List a function of each type of molecule in the table below.

Q.3: Fill in the blanks:

10. A receptor detects a signal molecule and carries out an action in response.

11. A ligand is a molecule that acts as a signal when it binds to

a receptor.

12. A ligand that can cross the cell membrane can bind to an intracellular receptor.

13. A ligand that cannot cross the cell membrane can send a message to a cell by binding to a

membrane receptor, which then changes shape.

Q.4: Answer the following questions:

16. The cell membrane allows some, but not all, molecules to cross. What term describes

this property?

Selective permeability

17. How do intracellular receptors differ from membrane receptor?

Internal receptors are located inside the cell, and their ligands enter the cell to

bind the receptor. ...

Cell-surface receptors, however, are embedded in the plasma membrane, and

their ligands do not enter the cell

Molecule Function

7. Cholesterol Cholesterol molecules strengthen the cell membrane.

8. Proteins Help materials cross the membrane.

9. Carbohydrates Serve as identification tags, enabling cells to distinguish one type of

cell from another.

SECTION 3.4 AND 3.5

Q.1: Complete the concept map below about passive transport:

Q.2: Answer the following questions:

a. What is a concentration gradient?

The difference in the concentration of a substance between two areas

Transport across cell membrane

............active transport........

...

Moves .against

concentration gradient

From lowconcentration

to highconcentration

includes:

Endocytosis

Ecocytosis

protein pumps

...passive transport

....................

Moves downconcentration

gradient

From highconcentration

to lowconcentration

Diffsion

Example: osmosis

Isotonic

hypertonic

hypotonic

facilitated diffusion

occurs by the help of

...........protien channels.............

...

b. What does it mean for a molecule to diffuse down a concentration gradient?

From high concentration to low concentration

c. What does it mean for a molecule to diffuse against a concentration gradient?

From low concentration to high concentration

d. Which solution has the highest concentration of particles?

A hypertonic solution has a higher concentration of dissolved particles then a cell

f. Which solution has the lowest concentration of particles?

A hypotonic solution has lower concentration of dissolved particles in a cell

h. So, The higher the concentration of dissolved particles in a solution, the

_______lower_______ the concentration of water molecules in that solution.

Q.3: Complete the Y diagram below to compare and contrast the processes of endocytosis

and exocytosis. Under the heading “endocytosis,” list the characteristics of endocytosis.

Under the heading “exocytosis,” list the characteristics of exocytosis. At the bottom of the Y,

write the characteristics that both processes have in common. Then lightly cross out those

characteristics at the top of the Y.

Endocytosis

Uses energy,

Takes substances into a cell,

Moves substances in vesicles

Exocytosis

Uses energy,

Releases substances outside a

cell

Moves substances in vesicles

Both

Use energy, move substances in vesicles.