A2.2 SL / HL Flashcards
1
Q
Cell theory
A
theory states thatall biological organisms are composed of cells; cells are the unit of life and all life come from preexisting life
2
Q
Prokaryotes
A
any organism that lacks a distinct nucleus and other organellesdue to the absence of internal membranes
3
Q
binary fission
A
the process of one cell simply dividing into two. It is most commonly used in archaea and bacteria, which are both prokaryotic organisms
4
Q
Eukaryotes
A
any cell or organism that possesses a clearly defined nucleus. The eukaryotic cell has a nuclear membrane that surrounds the nucleus
5
Q
mitosis
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a process of cell duplication, or reproduction, during which one cell gives rise to two genetically identical daughter cells
6
Q
meiosis
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a type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells
7
Q
Inductive reasoning
A
a form of logical thinking that uses related observations to arrive at a general conclusion
8
Q
spontaneous generation
A
the supposed production of livingorganismsfrom non-living matter, asinferredfrom the apparent appearance of life in somesupposedlysterileenvironments
9
Q
Deductive reasoning
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a form of logical thinking that uses a general principle or law to forecast specific results
10
Q
Theory
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a widely accepted explanation of a biological phenomenon based on sound evidence from rigorous empirical experiments and scientific observations
11
Q
microscope
A
an instrument that is used to magnify small objects
12
Q
Magnification
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the increase in size of an object when it is viewed through a microscope or other optical device
13
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Resolution
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the ability to distinguish two objects from each other. Light microscopy has limits to both its resolution and its magnification
14
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Field of view (FOV)
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the maximum area visible through the lenses of a microscope, and it is represented by a diameter
15
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Compound light microscope
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a high magnification microscope that uses 2 lenses to compound (multiply) the level of magnification
16
Q
Electron microscope
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an instrument that uses a beam of electrons to magnify a specimen. It has a higher resolution power of up to 100,000X
17
Q
Tunneling electron microscope (TEM)
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a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image
18
Q
Scanning electron microscope (SEM)
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a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons
19
Q
Freeze-fracture
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physically breaking apart (fracturing) a frozen biological sample
20
Q
Integral proteins
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a type of membrane protein that is permanently attached to the biological membrane
21
Q
fluid mosaic model
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describes the main characteristics of the plasma membrane
22
Q
Immunofluorescence
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a method commonly used in neuroscience to detect viral antigens by directly applying fluorescent dyes to samples, such as nasopharyngeal aspirate or biopsy samples, and observing them under a fluorescent microscope
23
Q
Fluorescent stains
A
a pivotal molecular technique that brings to light the structures within biological cells and tissues through fluorescence
24
Q
antibodies
A
proteins that protect you when an unwanted substance enters your body
25
Cryogenic electron microscope
a version of electron microscopy that freezes many copies of a delicate sample into a glassy state and hits them with an electron beam
26
permeability
the passage of molecules through a biological membrane or a barrier
27
plasma membrane
a microscopic membrane of lipids and proteins which forms the external boundary of the cytoplasm of a cell or encloses a vacuole, and regulates the passage of molecules in and out of the cytoplasm
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Hydrophobic
a property of molecules that do not mix with water
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cytoplasm
the gelatinous liquid that fills the inside of a cell. It is composed of water, salts, and various organic molecules
30
70s ribosomes
In prokaryotes, these subunits are 50S(large) and 30S (small). The total ribosome with both subunits is 70S in prokaryotes
31
80s ribosomes
found in the cytoplasm of eukaryotic cells
32
Capsule
a layer of slime outside the bacterial cell wall, composed mainly of polysaccharides or polypeptides
33
polysaccharides
long chains of carbohydrate molecules, composed of several smaller monosaccharides
34
Cell wall
a structural layer that surrounds some cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid
35
peptidoglycan
a polymer consisting of sugars and amino acids that forms a mesh-like peptidoglycan layer outside the plasma membrane of most bacteria, forming the cell wall
36
Phospholipid bilayer
a two-layered arrangement of phosphate and lipid molecules that form a cell membrane, the hydrophobic lipid ends facing inward and the hydrophilic phosphate ends facing outward
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Pili
short, hair-like structures on the cell surface of prokaryotic cells
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plasmids
a small, circular, double-stranded DNA molecule that is distinct from a cell's chromosomal DNA
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Flagellum
hairlike structure that acts primarily as an organelle of locomotion in the cells of many living organisms
40
metabolic reactions
a chemical process in living systems that transforms molecules to make them more chemically stable, permeable, polar, and less toxic
41
Nucleoid
an irregularly shaped region within the prokaryotic cell that contains all or most of the genetic material
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naked DNA
DNA that is not associated with lipids, proteins, or any other molecule to help protect it
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conjugation
the process by which one bacterium transfers genetic material to another through direct contact
44
antibiotic resistance
occurs when bacteria evolve to evade the effect of antibiotics through multiple different mechanisms
45
membrane-bound organelles
a membrane bound structure found within a cell
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compartmentalization
the separation of the cell interior in distinct compartments with specific local conditions that allow the simultaneous occurrence of diverse metabolic reactions and processes
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nucleus
the structure in a cell that contains the chromosomes
48
nuclear envelope
the nuclear membrane, is made up of two lipid bilayer membranes that in eukaryotic cells surround the nucleus
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Nuclear pores
a protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm
50
euchromatin
the less tightly coiled DNA that allows transcription factors and chromatin remodelers access, enabling transcription to occur
51
heterochromatic
a cytologically dense material that is typically found at centromeres and telomeres
52
histones
a family of basic proteins that associate with DNA in the nucleus and help condense it into chromatin
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nucleolus
spherical body within the nucleus of most eukaryotic cells, involved in the synthesis of ribosomal RNA (rRNA) and the formation of ribosomes
54
Smooth endoplasmic reticulum
tube-like structure located near the cell periphery. These tubules or tubes sometimes branch forming a network that is reticular in appearance. The network of smooth endoplasmic reticulum allows for an increased surface area to be devoted to storage of key enzymes
55
Rough endoplasmic reticulum
a cellular organelle composed of many folds of tissues and channels. It provides surface area for chemical reactions to take place. It is rough because its surface is covered with ribosomes. These ribosomes produce proteins
56
polypeptides
a continuous, unbranched chain of amino acids joined by peptide bonds
57
Free ribosomes
unattached to any cellular structure and float freely around in the cytosol
58
golgi apparatus
a complex of vesicles and folded membranes within the cytoplasm of most eukaryotic cells, involved in secretion and intracellular transport
59
vesicles
a structure within or outside a cell, consisting of liquid or cytoplasm enclosed by a lipid bilayer
60
exocytosis
a process for moving large molecules out of the cell to the cell exterior
61
Lysosomes
membrane-enclosed organelles that contain an array of enzymes capable of breaking down all types of biological polymers—proteins, nucleic acids, carbohydrates, and lipids
62
Transport vesicles
help move materials, such as proteins and other molecules, from one part of a cell to another
63
Secretory vesicles
a specialized cellular structure that carries proteins, peptides, or neurotransmitters for extracellular delivery in response to specific signals
64
cytoskeleton
a network of different protein fibers that provides many functions: it maintains or changes the shape of the cell
65
Microtubules
A narrow, hollow tube-like structure found in the cytoplasm (the fluid inside a cell) of plant and animal cells. Microtubules help support the shape of a cell
66
Actin filaments
the smallest component of the cytoskeleton, the internal protein skeleton of the cell
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Intermediate filaments
fibrous cytoskeletal polymers intermediate in size between 6-nm actin filaments and 23-nm microtubules that form the structural framework of nearly all eukaryotic cells
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centrioles
a cylindrical organelle composed mainly of a protein called tubulin
69
spindle fibers
a network of filaments that are formed during the cell division process. They help in the movement of chromosomes during both mitosis and meiosis
70
centrosome
an organelle present in an animal cell that acts as the microtubule-organizing centre of the cell. It also regulates the cell cycle
71
basal bodies
a minute distinctively staining cell organelle found at the base of a flagellum or cilium and resembling a centriole in structure
72
Cilia
short eyelashlike filament that is numerous on tissue cells of most animals and provides the means for locomotion of protozoans
73
Flagella
hairlike structure that acts primarily as an organelle of locomotionin the cells of many living organisms
74
mitochondria
a round to oval-shaped organelle found in the cells of almost all eukaryotic organisms. It produces energy, known as ATP, for the cell
75
cellular respiration
the process by which organisms combine oxygen with foodstuff molecules
76
ATP (adenosine triphosphate)
the source of energy for use and storage at the cellular level
77
protists
any member of a group of diverse eukaryotic, predominantly unicellular microscopic organisms
78
cell wall
structural layer that surrounds some cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid
79
osmotic stress
physiologic dysfunction caused by a sudden change in the solute concentration around a cell, which causes a rapid change in the movement of water across its cell membrane
80
cellulose fibers
a polymer made of repeating glucose molecules attached end to end
81
turgor pressure
the force within the cell that pushes the plasma membrane against the cell wall
82
large central vacuole
large, membrane-bound organelles found in plant cells that act as a storage space for water and other molecules in the cell
83
chloroplast
an organelle within the cells of plants and certain algae that is the site of photosynthesis
84
photosynthesis
the process by which green plants and certain other organisms transform light energy into chemical energy
85
chlorophyll
a pigment present in all green plants and a few other organisms. It is required for photosynthesis, which is the process by which light energy is converted into chemical energy
86
Metabolism
the chemical reactions in the body's cells that change food into energy
87
Catabolic reactions
break down larger molecules, such as carbohydrates, lipids, and proteins from ingested food, into their constituent smaller parts
88
Anabolic reactions
reactions that build smaller molecules into larger molecules
89
sensitivity
the ability of an organism or organ to respond to external stimuli
90
receptor proteins
proteins molecules located on the cell surface or within the cytoplasm that function by specifically recognizing and binding to a ligand molecule
91
homeostasis
any self-regulating process by which biological systems tend to maintain stability while adjusting to conditions that are optimal for survival
92
Conformers
Any organism whose internal environment is highly influenced by external factors
93
Regulators
Any organism whose internal environment is highly influenced by internal factors
94
Sessile
an organism that is anchored to a substrate and cannot move about freely
95
Motile
an organism has the capability to move under its own power
96
cell division
the division of a cell into two daughter cells with the same genetic material.
97
specialization
cells that have a distinctive structures and provide unique functions in the body
98
Asexual reproduction
a mode of reproduction in which a new offspring is produced by a single parent
99
clones
cell or organism that is genetically identical to the original cell or organism from which it is derived
100
Sexual reproduction
the production of new organisms by the combination of genetic information of two individuals of different sexes. In most species the genetic information is carried on chromosomes in the nucleus of reproductive cells called gametes, which then fuse to form a diploid zygote
101
gametes
a reproductive cell of an animal or plant
102
variation
any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences
103
Excretion
the process of removing wastes and excess water from the body
104
Nutrition
the process of taking in food and converting it into energy and other vital nutrients required for life
105
Domains
the highest taxonomic rank of all organisms taken together
106
Eubacteria
prokaryotic microorganisms consisting of a single cell lacking a nucleus and containing DNA is a single circular chromosome
107
Archaea
single-celled microorganisms with structure similar to bacteria
108
Eukarya
any cell or organism that possesses a clearly defined nucleus. The eukaryotic cell has a nuclear membrane that surrounds the nucleus
109
heterotrophs
an organism that eats other plants or animals for energy and nutrients
110
autotrophs
an organism that can produce its own food using light, water, carbon dioxide, or other chemicals
111
Saprotrophs
organism that feeds on nonliving organic matter known as detritus at a microscopic level
112
decomposers
An organism, often a bacterium, fungus, or invertebrate that feeds on and breaks down dead plant or animal matter, making organic nutrients available to the ecosystem
113
Erythrocytes
A type of blood cell that is made in the bone marrow and found in the blood. Erythrocytes contain a protein called hemoglobin, which carries oxygen
114
Haemoglobin
A protein inside red blood cells that carries oxygen from the lungs to tissues and organs in the body and carries carbon dioxide back to the lungs
115
muscle cells
the smallest subunit of all muscular tissues and organs throughout the body
116
multinucleated
eukaryotic cells that have more than one nucleus
117
Hyphae
The long filamentous branching in fungus and actinobacteria
118
mycelium
a network of fungal threads or hyphae
119
Aseptate hyphae
characterized by the absence of a cross wall, or septa. These hyphae contain many nuclei
120
phloem
plant vascular tissue that conducts foods made in the leaves during photosynthesis to all other parts of the plant
121
vascular plants
those varieties of plants that have special vascular tissue in them. The two types of vascular tissue, phloem, and xylem are behind the movement of water, minerals, and the products of photosynthesis
122
Sieve tube elements
thin-walled cells that are alive at maturity, although the protoplast is greatly changed, and they generally lack nuclei
123
companion cells
A type of cell found within the phloem of flowering plants. Each companion cellis usually closely associated with a sieve element
124
gram positive
bacteria classified by the color they turn in the staining method
125
gram negative
bacteria have an outer membrane. However, they have a thinner peptidoglycan cell wall. This means they do not hold the blue dye used in Gram testing and do not appear blue. Instead, they appear red or pink in color
126
microvilli
finger-shaped plasma membrane protrusions that are found at the surface of a large variety of cell types but are most numerous and elaborated on simple epithelial
