• Study Resource
  • Explore
    • Arts & Humanities
    • Business
    • Engineering & Technology
    • Foreign Language
    • History
    • Math
    • Science
    • Social Science

    Top subcategories

    • Advanced Math
    • Algebra
    • Basic Math
    • Calculus
    • Geometry
    • Linear Algebra
    • Pre-Algebra
    • Pre-Calculus
    • Statistics And Probability
    • Trigonometry
    • other →

    Top subcategories

    • Astronomy
    • Astrophysics
    • Biology
    • Chemistry
    • Earth Science
    • Environmental Science
    • Health Science
    • Physics
    • other →

    Top subcategories

    • Anthropology
    • Law
    • Political Science
    • Psychology
    • Sociology
    • other →

    Top subcategories

    • Accounting
    • Economics
    • Finance
    • Management
    • other →

    Top subcategories

    • Aerospace Engineering
    • Bioengineering
    • Chemical Engineering
    • Civil Engineering
    • Computer Science
    • Electrical Engineering
    • Industrial Engineering
    • Mechanical Engineering
    • Web Design
    • other →

    Top subcategories

    • Architecture
    • Communications
    • English
    • Gender Studies
    • Music
    • Performing Arts
    • Philosophy
    • Religious Studies
    • Writing
    • other →

    Top subcategories

    • Ancient History
    • European History
    • US History
    • World History
    • other →

    Top subcategories

    • Croatian
    • Czech
    • Finnish
    • Greek
    • Hindi
    • Japanese
    • Korean
    • Persian
    • Swedish
    • Turkish
    • other →
 
Profile Documents Logout
Upload
AS2 Revision Questions
AS2 Revision Questions

... 3. Complex tissues are composed of more than one cell type; name the cells that make up xylem. 4. What patterns of lignifications are found in xylem? 5. Describe the role of endodermal cells in the transport of water. 6. Name the two pathways water can take when it moves towards the stele. 7. Name a ...
Tissues and Membranes
Tissues and Membranes

... • Lacks striations • Also called involuntary muscle ...
Visceral Senses
Visceral Senses

... Bitter – produced by alkaloids such as quinine, strychnine and caffeine ...
AS Module 1 - heckgrammar.co.uk
AS Module 1 - heckgrammar.co.uk

... water depending on difference in water potentials. Hypotonic, hypertonic and isotonic solutions, and the importance of ion concentrations in maintaining cell turgor. • Active transport as the movement of molecules or ions through a membrane by carrier proteins against a concentration gradient, and a ...


... • Single layer of cells with different heights; some do not reach the free surface • Nuclei are seen at different layers • Function in secretion and propulsion of ...
pdf - Open Assembly
pdf - Open Assembly

... alive, they can do the things that we associate with life, they replicate, they reproduce, they metabolize, they can move, they can grow, and they can use nutrients and make wastes, and they work cooperatively in order to perform some function. This is a picture that I showed you before, but basical ...
Bacteria, Viruses, Protists, and Prions
Bacteria, Viruses, Protists, and Prions

... • Photoheterotrophs: are photosynthetic but also need to take in organic molecules for carbon source ...
Module 1 Notes
Module 1 Notes

... water depending on difference in water potentials. Hypotonic, hypertonic and isotonic solutions, and the importance of ion concentrations in maintaining cell turgor.  Active transport as the movement of molecules or ions through a membrane by carrier proteins against a concentration gradient, and a ...
Bacteria , Viruses, Protists , and Prions
Bacteria , Viruses, Protists , and Prions

... • Photoheterotrophs: are photosynthetic but also need to take in organic molecules for carbon source ...
I. Introduction to class
I. Introduction to class

... UNIFYING CONCEPTS OF ANIMAL STRUCTURE AND FUNCTION ...
Chapter 1: An Introduction to Anatomy and Physiology
Chapter 1: An Introduction to Anatomy and Physiology

... • makes blood cells • stores calcium and other minerals • movement • heat production • structure and support • senses environment • responds to stimuli • communicates with other organs ...
What is an organ? - Five Points of Life
What is an organ? - Five Points of Life

... - A large group of similar cells that work together to perform a specific function. - Example: Muscle cells form muscle tissue, nerve cells form nerve tissue, bone cells form bone tissue, skin cells form skin tissue, etc. ...
Practice Exam 4 - IWS2.collin.edu
Practice Exam 4 - IWS2.collin.edu

... B) respiratory alkalosis C) metabolic acidosis D) respiratory acidosis 34) A patient had 10 episodes of vomiting and you sent his blood for analysis. What lab results would you expect and what problem the patient is probably showing? a) high blood pH and metabolic acidosis b) low blood pH and respir ...
Year 1 - StudyWise
Year 1 - StudyWise

... provide an habitat for organisms. (II) Solvent: Because H20 molecules are dipolar they can separate out solutes based on their charge, +ve Hydrogen side mixes with -ve solute and -ve Oxygen side mixes with +ve solute, so solute mixes with water and becomes dissolved. This is useful in cytoplasm of a ...
- Toolbox Pro
- Toolbox Pro

... • Fertilization usually occurs in the upper one third of the oviduct. If the egg is not fertilized within approximately 24 hours after ovulation, it deteriorates. If fertilization occurs, cleavage of the fertilized egg (zygote) begins in the oviduct, and six to ten days later, the resulting embryo m ...
Topic 5 - GEOCITIES.ws
Topic 5 - GEOCITIES.ws

... and replicates there. The cells burst and release new viruses, these viruses infect other helper T cells and possibly other cells such as phagocytes as well. The destruction of helper T cells paralyses the immune system since they communicate between different cells of the immune system and activate ...
Systems - Jaguar Biology
Systems - Jaguar Biology

... SPECIFIC IMMUNE RESPONSE/ WHITE BLOOD CELLS • If pathogens pass the non-specific line of defense, specific defenses are employed to attack a specific pathogen– these are called the immune response • Pathogens carry antigens (like a nametag) which the body recognizes as an invader The cells that rec ...
Biology Paper - Acland Burghley School
Biology Paper - Acland Burghley School

... Describe how body cells divide by mitosis, including copying of the genetic material and  division to form two identical body cells  State that mitosis occurs during growth or to produce replacement cells  Compare the number of chromosomes in body cells and sex cells (gametes)  Identify the reproduc ...
multicellular organisms
multicellular organisms

... In vascular plants, transport of water and mineral nutrients from the roots occurs via xylem involving root pressure, capillary action transpiration (adhesion and cohesion of water molecules); transport of the products of photosynthesis and some mineral nutrients occurs by translocation in the phloe ...
Name
Name

... The immune system also releases chemicals that increase the core body temperature. You may have experienced this elevated body temperature, called a fever. The increased body temperature is advantageous because many pathogens can survive only within a narrow temperature range. An elevated temperatur ...
Biology formula and tips
Biology formula and tips

... Kingdom : Monera  The organisms included in this kingdom are microscopic and prokaryotic, having a primitive type of nucleus.  The cells are without membrane bound cell organelles ...
Learning Outcomes
Learning Outcomes

... A: Cell Biology (Cell Structure) It is expected that students will: A1. describe the following cell structures and their functions:   cell membrane   mitochondria   smooth and rough endoplasmic reticulum   ribosomes   Golgi bodies   vesicles   vacuoles   lysosomes   nuclear envelop ...
File
File

... 5. Ahmad has to make a model of body tissue. He knows that a body tissue is made up of many cells that have specific characteristics. Which of the following statements describes the characteristics of the cells that make up a tissue? F. The cells have similar structures and similar ...
Living building blocks
Living building blocks

... Cytoplasm is mostly water, but with a light microscope you can see specks and blobs floating in it. These specks and blobs are organelles, stored food particles (like fat globules or starch grains), and chemicals such as salts and proteins. Important chemical reactions take place in your cytoplasm. ...
2014 Biology STAAR EOC Review
2014 Biology STAAR EOC Review

... When HIV attacks a helper T cell, it binds to the cell membrane and enters the cell. Once the virus is inside the cell, it uses the cell’s structures to make new viruses. Then the virus destroys the cell and the new viruses are released into the bloodstream. They travel throughout the blood, infecti ...
< 1 ... 65 66 67 68 69 70 71 72 73 ... 203 >

Cell theory



In biology, cell theory is a scientific theory which describes the properties of cells. These cells are the basic unit of structure in all organisms and also the basic unit of reproduction. With continual improvements made to microscopes over time, magnification technology advanced enough to discover cells in the 17th century. This discovery is largely attributed to Robert Hooke, and began the scientific study of cells, also known as cell biology. Over a century later, many debates about cells began amongst scientists. Most of these debates involved the nature of cellular regeneration, and the idea of cells as a fundamental unit of life. Cell theory was eventually formulated in 1838. This is usually credited to Matthias Schleiden and Theodor Schwann. However, many other scientists like Rudolf Virchow contributed to the theory. Cell theory has become the foundation of biology and is the most widely accepted explanation of the function of cells.The three tenets to the cell theory are as described below: All living organisms are composed of one or more cells. The cell is the most basic unit of life. All cells arise from pre-existing, living cells, by biogenesis.
  • studyres.com © 2025
  • DMCA
  • Privacy
  • Terms
  • Report