Unit 1 Flashcards
State the 3 aspects of cell theory
The cell theory was given by Schleiden and Schwann, which was later modified by Rudolf Virchow. The three principles of cell theory are:
All living organisms are made up of one or more cells.
Cells are the basic structural and functional unit of living organisms.
All cells arise from pre-existing cells.
Outline the 7 characteristics of living things
M - metabolism ( all the chemical reactions an organism uses to take in and transform energy from the environment . - mammals change the chemical energy stored in plants and other animals into a form of energy called ATP that their cells can use)
R - reproduction ( Transfer of hereditary information to offspring )
S - sensitivity ( responds to changes in the environment)
H - homeostasis ( is the maintenance of a stable internal environment. For example body temperature, water content, glucose levels etc. stay constant even though the environmental conditions change. )
G - growth (Living organisms increase in size and number of cells.)
R - respiration ( break down glucose to release energy)
E - excretion ( is the removal of waste products from the body)
N - nutrition ( Nutrition provides the raw materials for growth and repair.)
what are viruses
Viruses are microscopic parasites, generally much smaller than bacteria. They lack the capacity to thrive and reproduce outside of the body
Sexual reprodution
Two parents supply the DNA • Hereditary information recombines from two organisms of the same species. • This occurs in most plants and animals.
Asexual reproduction
A single parent supplies DNA • Original and new organisms are genetically the same. • Bacteria, some plants and algae, and primitive animals (worms sponges and hydra)
Describe Pasteur’s experiment
Pasteur’s expriemnt in which broth was sterilised by boiling and then either exposed to air or protected from air borne spores in a swan necked flask, only the broth exposed to air became cloudy from the bacterial growth. Pasteur’s experiment helped establish that life did not spontaneously generate itself. It concluded that cells only arise from preexisting cells
Define classification
Classification in biology is the establishment of a hierarchical system of categories on the basis of presumed natural relationships among organisms. The science of biological classification is commonly called taxonomy.
Distinguish between analogous and homologous features
Analogous features are features that have similar functions but their anatomy and origin are different.
Homologous features have common origin and similar anatomy but carry out different functions
Outline how organisms are named according to binomial nomenclature
Each name has two parts, the genus and the species. For example, human beings belong to the genus Homo, and our species is sapiens - so the scientific name is Homo sapiens.
List the stages of the hierarchy of life ( Dumb king phillip came over from great spain )
Species
Genus
Family
Order
Class
Phylum
Kingdom
Domain
Cell membrane
Controlls passage of subdtances into and out of teh cell, semi permeable, forms cell boundary
The cell membrane, also called the plasma membrane, is found in all cells and separates the interior of the cell from the outside environment.
cell wall
( 4 points )
Structural layer found just outside teh cell membrane
semi- rigid, gives the cell support, prvenmts it from bursting and is made of cellulose ( in plants )
chloroplast
Chlorophyll containing organelle found inteh cytoplasm
chlorophyll
green pigment that traps energy for photosynthesis
vacuole
lager fluid filled sac that swells, pushing the cytoplasm against the cell wall making the cells turgid.
cells shrink when vacuole gets smaller ( plasmolyzed)
eukaryotic cells
cells taht contain a necleus and organelles, enclosed by a plasma membrane
Mitochondria
Rod-shaped structures found in cytoplasm
Location where aerobic respiration occurs and most of the cell’s ATP is produced
Bacterial cells
Bacterial cells have a more simple structure compared to animal, plant and fungal cells and are usually much smaller.
They still have a cell membrane and ribosomes, but they lack organelles such as the nucleus. However, bacteria still have DNA, including extra circular pieces of DNA called plasmids.
Plasmids
Small circular DNA molecules
life cycle of a cell
young cell - cell division - cell groth ( from here the cycle can repeat) - cell specialization - mature cell unable or unlikely to ver divide again
