BIOLOGY Quiz/Exam Reviewer Flashcards
is a fundamental principle made in the 1800s in biology that describes the properties and functions of cells.
Cell theory
- discovered cells on cork from oak
- coined the term “cell”.
Robert Hooke (1665)
called protozoans as “animalcules” - observed his teeth
- scrapings, he found animalcules shooting and spinning inside the cell.
Anton Von Leeuwenhoek (Late 1600s) -
- German botanist
- concluded that “all plants have cells”
Matthias Schleiden (1838)
- German zoologist
- concluded that “all animals have cells”
Theodor Schwann (1839)
- studied cell cultures
- discovered that cells divide
Rudolf Virchow(1858)
- discovered the nucleus
- concluded that the nucleus is important and is a basic part of the cell
Robert Brown (1831)
- supported the idea that all cells come - from pre-existing cells
Louis Pasteur (1849)
- invented a primitive microscope with the help of his father Hans.
Zacharias Janssen (1590)
- Grew Conducted separated investigations on plant cell. They determined the presence of organelles within its cells
Marcello Malpighi and Nehemiah
The Three Postulates of Cell Theory
- All living things are composed of one - or more cells.
- The cell is the basic unit of life.
- All new cells arise from pre-existing cells
Major Parts of the Cell
Plasma Membrane
Cytoplasm
Nucleus
Outer covering that separates the cell’s interior from its surrounding environment. ● It also controls the exchange of essential component
Plasma Membrane
the organelles are suspended in a gel-like solution called cytosol that accounts for about 70% of cellular content.
also contains enzymes that break down waste and enable metabolic reactions.
Cytoplasm
● It is the most vital part of the cell
● It directs all of the cell’s activities and determines how a cell should appear and function.
● A double layer of nuclear membrane encloses the nucleus to keep it distinct from other cellular components.
● _________ serves as the site of ribosomes synthesis.
● _________ holds chromosomes which carry tightly wrapped DNA.
Nucleus
Specialized structures within a cell that perform specific functions necessary for the cell’s survival and operation
Organelles
is a series of interconnected sacs and tubules that modifies proteins and synthesized lipids.
Endoplasmic Reticulum
are molecular machines found within all living cells that perform biological protein synthesis (translation).
Ribosomes
● Vacuoles are membrane-bound organelles that store nutrients, waste products, and help maintain turgor pressure in plant cells.
● Store water, nutrients, and waste products.
Vacuoles
is a series of stacked membranes that modify, sort, and package proteins and lipids for storage or transport out of the cell.
Golgi Apparatus
are membrane-bound organelles containing enzymes that break down waste materials and cellular debris.
Lysosomes
It is the major energy currency of the cell that provides the energy for most of the energy-consuming activities of the cell.
ADENOSINE TRIPHOSPHATE
are the simplest type of cell.
- Oldest type of cell appeared about four billion years ago
-_______ are the largest group of organisms
- _______ unicellular organisms that are found in all environments.
- _______ do not have a nuclear membrane. Their circular shaped genetic material dispersed throughout cytoplasm.
-_______ do not have membrane-bound organelles.
- _________ are smaller in size when compared to Eukaryotes.
Prokaryotes
appeared approximately one billion years ago
- Nuclear membrane surrounds linear genetic material (DNA)
- Unlike prokaryotes, _________ have several different parts.
- Prokaryote’s organelles have coverings known as membranes.
- ________ have a complex internal structure
Eukaryotes
is a group of cells with a common origin, structure and function. Their common origin means they are derived from the same layer of cells in the embryo.
Tissue
Composed of immature cells without intercellular spaces.
Meristematic (meristos : dividing)
-Permanent tissues are those in which growth has stopped either completely or for the time being.
Permanent tissues
is made up of only one type of cells. Some tissues are parenchyma, and collenchyma.
Simple tissues
is made up of more than one type of cells working together as a unit.
Complex tissues
-line the surfaces, help in absorption, secretion, and also bear protoplasmic projections such as the cilia
-They are closely packed with no intercellular spaces in between.
- They arise from a non-cellular basement membrane.
- They are not supplied with blood vessels. - single layer: simple eptihelium.
- many layers: stratified epithelium. Found where there is lot of wear and tear. Like the skin and inner lining of cheeks.
Epithelian tissues
Most widely spread connective tissue.
Areolar
It has specialized cells which store fat and provide
help in forming paddings.
Adipose tissue
It is mainly made up of fibroblasts. It forms tendons and
ligaments.
Fibrous
is a flexible and strong type of connective tissue in
most of the vertebrates usually
occurring as part of their
endoskeleton.
Cartiliage
the bone cells are irregularly arranged. Such bones are found at the ends of the of long bones.
Spongy bones
are the two forms of liquid connective tissue.
Blood and Lymph
Function in defence against bacteria, viruses and other invaders.
White blood cells (Leucocytes)
help in the clotting of blood.
Platelets (Thrombocytes)
is the extracellular fluid matrix in the ground substance.
Plasma
Composed of long excitable cells containing parallel microfilaments proteins, as in actin, myosin, troponin and tropomyosin.
MUSCLE TISSUE
Elongated, cylindrical, unbranched fibres Myofibrils so
arranged in the cytoplasm, that
there are striations seen.
Striated
Spindle shaped, and tapering. No striations are seen
Unstriated
Elongated, branched. cylindrical, Striations seen
Cardiac
The functional unit of nervous tissue
are also called nerve cells
Nervous tissues constitute the brain, spinal cord, nerves and the sensory cells and sense organs.
NERVOUS SYSTEM
also known as glial cells, are non-neuronal cells in the nervous system that provide support, protection, and nutrition to neurons
Neuroglia Cells
Divides forming two new identical cells. (Prokaryotes)
Binary fission
Cell or organism growthand the replacement or repair of damaged cells. (Eukaryotes)
Mitosis
Formation of sex cells, or gametes. (Eukarytoes)
Meiosis
BINARY FISSION
- Three major steps;
- DNA Replication: DNA is copied resulting into two identical
chromosomes - Chromosome Segregation: Chromosomes separate and move
towards ends (poles) of cell - Cytokinesis (Separation) : Cytoplasm divides forming two (2)
cells
MITOSIS
- Two (2) main steps:
- Mitosis: Fours steps; Prophase,Metaphase,Anaphase,Te
lophase - Cytokinesis: Cytoplasm divides forming two new daughter cells
eriod of growth and DNA replication between cell divisions
INTERPHASE
INTERPHASE
G1 Phase
Replication of DNA.Two sister strands of DNA called chromatids are produced
S Phase
Organelles double, New cytoplasm forms, All other structures needed for mitosis for
G2 Phase
- Nucleus disappears
- Spindle fibers form in the cytoplasm - Spindle fibers attach to sister chromatids
I. Prophase
- The sister chromatids are pulled to the center of the cell
- They line up in the middle of the cell
II. Metaphase
- Spindle fibers begin to shorten
III. Anaphase
- The sister chromatids are pulled to the opposite ends of the cell
CYTOKENESIS
- The sister chromatids arrive at the opposite poles of the cell and begin to unravel
cytoplasm - Results in two separate daughter cells with identical nuclei
IV. Telophase
- It is the process of cell division that produces haploid gametes (half the number of chromosomes: humans: 23) (Total: 46)
- In 1882, British cytologist Pierre-Joseph van Beneden observed that gametes (sperm & egg) contain half the number of chromosomes.
- An egg and a sperm fuse to produce a zygote that contains two copies of each chromosome (one copy from the sperm and one copy from the egg). These are called homologous chromosomes. This is caled fertilization.
Meiosis
are small, membrane-bound organelles that contain enzymes for oxidation reactions, breaking down fatty acids and detoxifying harmful substances.
Peroxisomes
Convert hydrogen peroxide into water and oxygen.
Detoxification:
Involved in the breakdown of fatty acids.
Lipid Metabolism
are organelles that serve as the main microtubule organizing centers in animal cells, playing a crucial role in cell division.
Centrosomes
Play a key role in the formation of the mitotic spindle during __________.
Cell Division
are oval-shaped organelles found in most eukaryotic cells. They are considered to be the ‘powerhouses’ of the cell.
are most plentiful in cells that require significant amounts of energy to function, such as liver and muscle cells.
Mitochondria
