biology parcial Flashcards
Characteristics of living things
Organization: Genetic code Response to stimuli Homeostasis Metabolism Growth Reproduction Adaptation and evolution
Organization:
In living things, the components are organized complexly. Nothing can exist or function
without this complex organization.
Genetic Code
All living things share an essential characteristic: The genetic code
Response to Stimuli:
Perception and response to stimuli that come from the external and internal
environment
Homeostasis
While everything in the universe tends to chaos, life strives to maintain its balance, even
if it has to spend energy to achieve this.
Metabolism:
Obtaining and using energy ,Metabolism involves the destruction of
molecules, that is catabolism, and the formation of new molecules, or anabolism
Growth
All living things, to a greater or lesser extent, increase their volume, that is, they grow.
Reproduction
To perpetuate their species, individuals must reproduce themselves.
Asexual reproduction:
Its main characteristic is the fact that the descendant is genetically identical to its predecessor, since in this modality, sperm and ovules are not involved
Sexual reproduction
involves the fertilization of two different cells: the
sperm and the egg. Increased possibilities of adaptation to the changing environment,
Parasexual reproduction
Genetic variability is achieved through the exchange of DNA that is carried out by: o Conjugation o Transduction o Transformation
Adaptation Ability and Evolution:
forced to adapt and evolve in order to survive, if it does not happen, the punishment will be the extinction
Who invented the Compound Microscope?
Zacharias Janssen (1590) The magnification range achieved by this microscope was between 3x and 9x
first person who names this invention as “the microscope”
Giovani Faber in 1625.
History of the Cell:
The story begins with Robert Hooke, who in 1665 published the observations he made with the microscope he created
Anton van Leeuwenhoek, with the lenses he had crafted, observed and described in more detail cells
such as spermatozoa and protozoa, and even some bacteria.(1674)
Theodor Schwann and Matthias Schleiden proposed the first postulate of the cell theory: the cell is the elemental unit of plants and animals.
Robert Brown (1831) described the nucleus in plant cells.
Johannes Evangelista Purkinje (1839) introduced the term protoplasm, that is, he was the first to
describe the cellular cytoplasm.
Rudolph A. von Kölliker identified the mitochondria (1857)
Rudolf Virchow proposed that all cells come from preexisting cells (1858)
Lynn Margulis (1981) proposed the endosymbiotic theory, which explains, with solid arguments, the origin of eukaryotic cells
Cell Theory
The cell is the morphological and structural unit of all living things;
Omnis cellula ex cellula
The cell is the physiological unit of life
The cell contains the hereditary information
cell
complex thermodynamic structures that use energy to maintain the conditions that make possible
their existence
Structure and Function of the Cell:
they share the following three characteristics:
Cell membrane: Defines the boundary between the cell and the environment that surrounds it; it
is the structure that allows it to have individuality.
Cytoplasm: The organelles are immersed.
Genetic material: Cells have DNA
smallest cell known so far
Mycoplasma genitalium (.2 micrometers)
main difference between eukaryotic and prokaryotic cells
eukaryotes have an endomembrane system, whereas prokaryotes do not
Prokaryotic Cell
Prokaryotes are cells without a nucleus. The most noticeable difference is that their genetic
material is found in the cytoplasm, in an area called the nucleoid. They are also unicellular
and can be reproduced asexually or parasexually
The components in all prokaryotic cells include
o Cell membrane
o Cell wall (except in some cells such as mycoplasmas)
o Cytoplasm
o Nucleoid (is the genetic material)
o Ribosomes
o Prokaryotic compartments (chlorosomes, carboxysomes, proteasomes, and
magnetosomes)
o The cell may have: flagella
They can be anaerobic or aerobic, heterotrophs or autotrophs.
Eukaryotic Cell
There are two types of eukaryotic cells: the animal and the plants
o Animal Cell organelles and structures
The components of the animal cell are: Cell membrane: Membranous organelles: Nucleus: Rugg endoplasmic reticulum (RER) Smooth endoplasmic reticulum (REL) Golgi apparatus (GA): Lysosomes: Peroxisomes: Mitochondria: Not membranous organelles: Cytoskeletal elements: Centrosome: Centrioles Cytoplasmic inclusions:
Organelles and structures that are found in plant
cells:
Cell wall: Central vacuole: Plastids: Chloroplasts Leucoplasts Chromoplasts Amyloplasts Elaioplasts Glyosysome: Plasmodesma
organelles that have a similar composition and function in both cell types
membrane, nucleus, cytoskeleton, Golgi apparatus, ribosomes, endoplasmic reticulum, mitochondria, and
peroxisomes.
what passes through the cellular transport
nutrients or molecules
transport can be classified according to the amount of molecules that pass through the membrane
Active transportation
This transport spends energy and goes against gradients of concentration.
Passive Transportation
This transport does not waste energy and foes in favor of concentration gradient. it can be
simple difussion,
facilitated difussion and ultrafiltration or dialysis
Mass transport
formation of small membrane vesicles that are incorporated into or separated from the plasma membrane
endocytosis
incorporation of material into the cell.
Pinocytosis: .
Phagocytosis:
Receiver-mediated endocytosis:
Exocytosis
secretion of the material produced by cells.
Regulated:
Constitutive:
levels of organization
Atom – Molecule - Cellular organelles – Cell – Tissue – Organ – Organ system – Organism –
Population – Community – Ecosystem – Biome
