Name:_____________________( ) Class:__________ Date:__________

Cells

At the end of the chapter, students should be able to:

1. Identify organelles of typical plant and animal cells from diagrams, photomicrographs and as seen under the light microscope using prepared slides and fresh material treated with an appropriate temporary staining technique :

a. Chloroplastsb. Cell membranec. Cell walld. Cytoplasme. Cell Vacuole (Large, sap-filled in plant cells, small, temporary in animal cells)f. Nucleus

2. Identify the following organelles from diagrams and electronmicrographs-mitochondria

-ribosome3. State the functions of the organelles identified above.4. Compare the visible differences in the structure of an animal cell and a plant cell 5. State in simple terms, the relationships between cell function and cell structure for

the following : - Absorption (root hair cell)- Conduction and support (xylem vessel)- Transport of oxygen (red blood cell)

6. Differentiate cell, tissue, organ and organ system

Cells: the Building Blocks of Life

Cell is the building block in living things

The cell contains information that is used as instructions for ________________, ___________________ and _________________.

The cell is the ________________ unit of life; the ________________________ of life takes place within the cell.

Parts of a Cell

A cell consists of living matter.o It contains __________________, ________________ and

_____________________.

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Nucleus

Consists ofo _______________________ that contain hereditary material DNA.

The DNA carry codes containing information controlling all cell activities

o _______________________, a spherical structure that forms ribosomes.

Ribosomes are involved in protein synthesis.

o ________________________, surrounds the nucleus and controls substances moving in and out of nucleus.

Functions of nucleus:

o Controls activities in cell, e.g. chemical reactions in the cell

o Responsible for cell reproduction and continued survival of cell, passing genetic information (DNA) from one generation to another.

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Cytoplasm

Consists of semi-fluid medium called cytosol surrounding the nucleus.

Function:

o It is the place where most life processes, eg, ____________________ occur in the cell.

o __________________, small structures that carry out particular functions each, are found in the cytoplasm.

Plasma Membrane

Surrounds the cytoplasm.

Function:

o It is a ___________________________ -- it only allows certain substances to move in and out of the cell.

o Transfers chemical messages from outside the cell to the inside.

o Keeps the contents of cell inside.

Mitochondria

Found in the cytoplasm.

Function:

o Releases ____________________ from food during cellular respiration.

o Energy released in the form of molecules called ATP (adenosine triphosphate)

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Ribosome

Can be found attached to membranes of structures (organelles) like extended nuclear membrane or in small groups suspended in the cytoplasm.

Function:

o Makes _________________.

Vacuole

A large, central vacuole in a plant cell is a ___________________ space enclosed by a membrane that pushes the cytoplasm to the edge of the cell.

Animal cells may contain many small, _____________________ vacuoles.

Function:

o In plant cells:

Contains cell sap that consist of dissolved sugars, salts and amino acids

o In animal cells

Stores sugars

Transport substances from one part of the cell to another

Contain digestive enzymes to digest bacteria coming into the cell

Help cell get rid of excess water.

Cell Wall

Only found in plant cells. Forms the outermost layer of the plant cell.

Functions:

o Protect cell from harmful external substances, eg, pressure from surrounding cells

o Maintain the shape of the cell

o Prevent cell from bursting when there is too much water

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Chloroplasts

Found in plant cells

Contains green pigment called __________________, that’s why plant cells are green.

Function:

o For photosynthesis (making sugars/food from carbon dioxide, water and light energy)

Comparison between Plant and Animal Cells

Similarities

Both have a _____________________________ surrounding the cell

Both have ___________________

Both have ________________ each

Both contain ____________________ and __________________

Differences

Animal Cell Plant Cell

Cell Wall

Chloroplasts

Vacuole

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Specialised Cells, Tissues and Organs

Most cells, after growing and dividing, become __________________

o They do one particular job

o Have specific shapes

o Undergo ___________________ in their cytoplasm to help them carry out their functions.

The structures of these specialized cells are _____________ to perform its particular function.

Xylem Vessels (Look at Chapter 8)

Function of the xylem

o Transport water and dissolved mineral salts up from the roots

Structural feature Adaptation of structure to function

Xylem vessels made up of long cells joined end to end. End walls between adjacent cells are _____________________ and there is no other structures.

Adjacent cells joined end to end allows a continuous flow of water with ___________ resistance up the plant.

There is ________________, a tough substance, on its wall.

To prevent stem from ________________ when water is pulled up the plant.

Provides _________________________ to the plant.

Root Hair Cell

Function:

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o To absorb water and mineral salts

Structural feature Adaptation of structure to function

Many root hair cells. Tiny, ______________ and narrow extensions of cells of root surface.

Long and narrow shape of root hair ________________ surface area to volume ratio for faster absorption of water and mineral salts from soil.

Red Blood Cells (Look at Chapter 7)

Red blood cells contain a red pigment called _____________________ that binds to oxygen.

o This enables red blood cells to ___________________ oxygen.

Structural Feature Adaptation of structure to function

_____________________ shape (thinner center)

Biconcave shape increases surface area for diffusion of oxygen into and out of cell faster.

Does not have _________________ Enable cytoplasm of red blood cell to contain more haemoglobin to carry more oxygen

Cells, Tissues, Organs and Organ Systems

Cells which carry out the same specific activity is grouped together -- ____________

Examples:

muscle cells make up muscle tissues. The tissue contact or relax to enable movement

nerve tissue detect changes and pass messages within the body epithelial tissue lines inner and outer surfaces in the body connective tissue support and join other cells or structures in the body

A group of tissue working together -- ________________.

Example: all the tissues in the stomach work together, making up the stomach (organ)

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A group of organs working together -- _________________.

Example: the mouth, stomach and intestines are organs in the digestive system.

Summary:

Orgenelles makes up cells which makes up tissues which makes up organs which make up organ systems which make up organisms.

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