Cells

Advanced Animal Science

Questions to ponder (sgpt)

• 1. What is a cell?

• 2. Are cells alive?

• 3. Where do cells come from?

Cell Theory

• A. All organisms are made of one or more cells• B. Cells are alike in their structure and

composition• C. All cells carry out similar functions that

keep them alive• D. New cells arise only from old cells, usually

by dividing into two equal parts at regular intervals

• Have you ever seen a cell? • Describe what you remember about it.

• Most cells are very, very small, so tiny that they can only be seen with the aid of a microscope. Your body is composed of billions of cells!

• Within your body, cells have different functions. We have blood cells, skin cells, brain cells...the list goes on. Despite their differences, cells in living organisms for the most part have similar structures and functions.

What are cells made of?

• http://www.youtube.com/watch?annotation_id=annotation_937748&feature=iv&src_vid=LP7xAr2FDFU&v=fKEaTt9heNM

• You may want to take notes!!

Handout

• Color the Plant and Animal Cells and give the function of each of the organelles listed.

Plant Cells

• http://www.youtube.com/watch?v=ASYG1JQy7K4

The differences between plant and animal cells

PLANT CELLS1. Cell wall

a. Made of celluloseb. Gives support and shape

2. Plastidsa. Leucoplasts

(1) Colorless structures where glucose is changed into starch

(2) Storage for starch, lipids or proteinsb. Chromoplasts (1) Manufacture and store pigments

(2) Give fruits, vegetables and leaves their bright color

c. Chloroplasts (1) Contain green chlorophyll pigment (2) Site of photosynthesis (food

production) in the plant cell

ANIMAL CELLS1. Microtubules give the

cell its shape

2. Centriolesa. Located near nucleus

b. Function in cell division for reproduction

Specialized Animal Cells

• http://www.youtube.com/watch?v=I8uXewS9dJU

Blood cells

1. Red blood cells contain hemoglobin to carry oxygen to cells and carbon dioxide from cells

2. White blood cells--important in body defense

– a. Phagocytic leukocytes flow to the infection site and engulf the bacteria

– b. Lymphocytes attack foreign cells directly or secrete an enzyme that immobilizes foreign substances

– c. Many white blood cells die while defending the body and make up pus

3. Platelets--important in blood clotting

Nerve Cells

• Carry messages and direction throughout the nervous system

Muscle Cells

1.Striated--Skeletal or voluntary muscle cells (controlled by conscious choice)

2. Smooth--Involuntary muscle cells found in

the walls of the digestive tract, blood vessels, urinary organs and reproductive organs

3.Cardiac--Conduct impulses within the heart

Bone Cells

Make up most of the skeleton on vertebrate animals

Fat Cells

1.Make up fat (adipose tissue) which is deposited around internal organs, between muscle branches and under the skin

2.Supplies reserve energy when food supply is scarce or sporadic

Gamete (Sex Cells)

• 1. Reproductive cell

• 2. An egg or sperm