Cell Model and Euglena

• Model of cells represents the basic units of life

Euglena

• Euglena possesses characteristics of both plants and animals.
• It produces its own food using sunlight, similar to green plants.
• It consumes other smaller organisms and moves with a whip-like tail, resembling animals.
• Euglena lacks a cell wall, a characteristic shared with animal cells rather than plant cells.
• Scientists have researched using Euglena to potentially produce aviation fuel due to its high oil content.

What are Cells?

• Cells are the fundamental building blocks of all organisms.
• Bacteria are single-celled (unicellular) organisms that can be spherical, rod-shaped, or spiral.
• Most plants and animals consist of multiple cells; the human body has trillions of cells.
• Organisms consisting of many cells are known as multicellular organisms.
• Cells have diverse shapes, sizes, and structures depending on their functions.
• Microscopes are essential for studying cells as most of them are too small to observe with the naked eye.
• Common laboratory microscopes can magnify objects up to 1,000 times, while the most powerful ones can magnify objects up to 10,000,000 times.
• Typical cells serve as models to explain structures and functions, aiding in understanding bodily processes.
• Cells can be classified by similarities in their structure.
• Representative cells of each category are called typical cells.
• Nerve cells have long extensions.
• Red blood cells are round and biconcave in shape.
• Guard cells, found on leaf surfaces, are bean-shaped.
• The yolk of a chicken egg measures from 15 to 17 cm in diameter.
• The yolk of an ostrich egg is the largest cell on earth.

Cell Structure and Function

• The nucleus is the largest structure in an animal cell, spherically shaped, and contains genetic material called chromosomes.
• It controls cell activities, cell reproduction, and keeps the cell alive.
• Chromosomes are located in the nucleus and contain genes that carry hereditary genetic materials, passed down from parents.
• Vacuoles are fluid-filled spaces within the cytoplasm, surrounded by a membrane, and contain water and nutrients for the organism's survival.
• Animal cells usually have small, numerous, temporary vacuoles.
• Plant cells typically have a single large vacuole enclosed by a membrane.
• Plant cells contain cell sap, a liquid made up of water and dissolved materials like sugars and mineral salts.
• Red blood cells do not have a nucleus and die quickly: the human body loses around 2 million red blood cells every second.
• The body produces new red blood cells daily.
• Chloroplasts contain chlorophyll, which absorbs sunlight for photosynthesis.
• The cell wall is a thick layer surrounding the cell membrane in plant cells, contains cellulose, and gives it a regular shape
• Cytoplasm is a jelly-like substance containing chemicals and organelles for carrying out specific functions.
• The cytoplasm serves as the site for chemical reactions.
• The cell membrane is a thin, partially permeable structure that surrounds the cell, serves as a boundary, and controls substances entering or leaving.
• Protoplasm consists of the nucleus, cytoplasm, and cell membrane, making up the living material of the cell.
• Plant cell is a type of regularly shaped plant cells which are densely packed with chloroplasts and are usually found in the upper layer of leaves.

Cell Organization

• Unicellular organisms are simple organisms consisting of only one cell.
• Multicellular organisms are complex and made up of many organized parts and different types of cells.
• Cells organize into tissues, then organs, and finally, organ systems in multicellular organisms.
• Cells with specific functions organize into tissues.
• Tissues group into organs
• Organs group into organ systems.
• Examples of unicellular organisms include bacteria and microscopic algae.
• Most cells in multicellular organisms have specific functions
• Cells with similar functions group together to form tissues.
• Tissues that work together to perform a function form an organ.
• Several organs with related functions work together for a specialized purpose as an organ system.
• Circulatory system consists of organs like the heart, arteries and veins which all work together to transport blood to all areas of the body.
• Digestive system consists of organs that break down nutrients in food, and works together with other organs in order to support the body.
• Leaves consist of tissues organized to perform photosynthesis where food substances are formed.
• The root system takes in water and dissolved minerals to be transported by the shoot system, in order to conduct photosynthesis, as part of the transport system of the plant.

Division of Labour in Organisms

• Division of labor allows organisms to efficiently perform various functions simultaneously.
• The division of labor is the breakdown of work into small and more specific tasks for maximum efficiency.
• In a green plant cell, the cell membrane regulates substances entering and leaving, and the chloroplasts enable the cell to make its own food.
• In multicellular organisms, work is divided among each type of cell, tissue and organ
• The division of labor allows an organism to carry out its functions more efficiently.
• The respiratory system enable us to take in oxygen needed to release energy from the food we eat
• Our muscle tissue in the muscular system uses the released energy to contract and relax so that we can move about.
• The heart functions as the our circulatory system which pumps blood aroundthe body and and transport oxygen all parts of the body.