Biology Flashcards
1
Q
What is the Cell Theory?
A
- all organisms are made of cells
- cells are units of life
- contain genetic information
- have a function
- have a metabolism
- can reproduce
- all cells are produced from cell division (biogenesis)
2
Q
What are Exceptions to cell theory?
A
1) viruses- cannot survive outside host; not considered to be living
2) striated muscle- type of muscle cell with multiple nuclei, several bundled together by single membrane
3) fungal hyphae- make up bodies of fungi and have multiple nuclei, join together to form a continuous cytoplasm
3
Q
What are organelles?
A
Smaller components of cells
4
Q
What are cells?
A
Become specialized to form tissue
5
Q
What are stem cells?
A
Unspecialized cells
6
Q
What is tissue?
A
Specialized cells
7
Q
What are organs?
A
tissue with similar functions work to form organs
8
Q
What are organ systems?
A
Organs with similar functions work together in systems
9
Q
Who created the first microscope and when?
A
Hans and Zacharias Janssen in 1595
10
Q
What did Robert Hooke do?
A
Robert Hooke invented a three lens system for magnifying flying objects and coined with the term ‘‘cell’’
11
Q
What did Leeuwenhoek do?
A
Antoni Van Leeuwenhoek made the first observations of single celled organisms ‘‘animacules’’
12
Q
What does the revolving nose piece do?
A
Holds objective lenses
13
Q
What do the object lenses do?
A
have different levels of magnification power (4, 10,40)
14
Q
What do stage clips do?
A
Hold slide in place
15
Q
What does the stage do?
A
It is where the slide is placed for support and viewing
16
Q
What does the diaphragm do?
A
It regulates the amount of light passing through stage opening
17
Q
What does the light source do?
A
Supplies light for viewing slide
18
Q
What does the base do?
A
Supports microscope
19
Q
What does the switch do?
A
Turns machine on and off
20
Q
What does the fine adjustment knob do?
A
makes image sharp (use with medium and low power)
21
Q
What does the coarse adjustment knob do?
A
moves stage up and down (use only with low power)
22
Q
What does the arm do?
A
supports revolving nosepiece and body tube. use to carry
23
Q
What does the body tube do?
A
supports ocular lens
24
Q
What does the eyepiece do?
A
ocular lens; look through to observe
25
What is staining?
Addition of a stain to cell samples can help with observation by increasing contrast
26
What is fluorescene?
Technique that can be used to show molecules on the membrane of cells in more detail
27
How do you convert mm to um?
1 mm= 1000um
28
What are processes essential to cell functioning?
- nutrient intake
- movement
- growth
- response to stimuli
- gas exchange
- waste removal
- reproduction
29
What are prokaryotic cells?
They make up bacteria and archaea
30
What does a mesosome do?
It is where DNA is replicated
31
What does the nucleoid and plasmid do?
Both contain DNA
32
What do pili do?
Aid in communication between prokaryotic cells
33
What do ribosomes do in prokaryotic cells?
they are required to translate DNA into proteins (70S for prokaryotes, 80S for eukaryotes)
34
What does a capsule do?
Prevents cell from drying out, and allows the cell to adhere to surfaces
35
What does a flagellum do?
Only some prokaryotes have them; it allows them to move
36
What are eukaryotes?
Cells that make up plants, animals, fungi, and protists
37
What does a nucleus do?
Controls all cellular activities where DNA is stored
38
What does a lysosome do?
Digest/break down waste and other particles
39
What does a smooth endoplasmic Reticulum do?
Makes lipids for delivery out of cell
40
What does a golgi body do?
receives substances from the ER and packages them for transport out of the cell
41
What does a rough endoplasmic reticulum do?
makes proteins for delivery out of cell
42
What do ribosomes do in eukaryotic cells?
Translate MRNA (modified DNA) from nucleus into sequences of amino acids (proteins)
43
What does the cytoplasm do ?
Jelly like substance found through cell
44
What does the cell membrane do?
Controls movement of materials in and out of the cell
45
What does the mitochondria do?
Cellular respiration; provides ATP
46
What is ATP?
Form of energy organisms can use created from glucose in cellular respiration
47
What does a cell wall do?
Provides shape and support
48
What do chloroplasts do?
It is where photosynthesis takes place
49
What do vacuoles do?
Stores water and other substances
50
What is the equation for cellular respiration?
Glucose+oxygen = carbon dioxide+water+ATP
C6H12O6+O2 = CO2+H2O=ATP
51
What is the equation for photosynthesis?
carbon dioxide+water = glucose+oxygen
6CO2+6H2O = C6H12O6+6O2
52
What is the cell membrane made of?
The phospholipid bilayer- made of double layer of phospholipids with proteins and other molecules embedded within
the head is hydriophilic
tail is hydrophobic
53
What is trilaminar model?
- proposed in 1935 by Davson and Danielli
- proteins layers ''sandwich'' lipids
- based on electron micrograph, proven wrong
54
What is the fluid mosaic model?
- proposed in 1972 by singer and nicolson
- proteins embedded in lipid bilayer
- accurate
55
What are the two types of membrane proteins?
1) Integral- span lipid bilayer, permanently embedded
2) peripheral- associate with surface of membrane, temporarily attached
56
What are the roles of membrane proteins?
- intercellular joinings
- enzymatic activity
- transport (active/passive)
- cell~cell recognition
- anchroage/attachment
- signal transduction
57
What does cholesterol do in the membrane?
Acts to maintain fluidity of membrane, also reduces permeability to small, water soluble solutes
58
Why is selective transport important?
It maintains the concentration gradient, an equilbrium in and out of the cell would disrupt cellular activity
59
What is an isotonic solution?
Concentration of solute and solution almsot the same
60
What is a hypotonic solution?
Concentration of solute lower outside cell; water moves into cell by osmosis
61
What is a hypertonic solution?
Concentration of solute higher outside cell; water moves out of cell by osmosis
62
What is passive transport?
movement of molecules down a concentration gradient without an input of energy from the cell
63
What is diffusion?
movement of solute particles from area of high to low concentration (how gas exchange works)
64
What is osmosis?
Movement of water molecules from an area of high to low concentration
65
What is facilitated diffusion?
transport of substances that cannot cross the membrane themselves without proteins
66
What is active transport?
requires energy to occur
67
What is exocytosis ?
molecules unable to dissolve or diffuse or are to large to cross membranes must be released through exocytosis
68
What is endocytosis?
molecules unable to dissolve or diffuse or are to large to cross membranes must be takien into the cell by endocytosis
69
What is pinocytosis?
''cell drinking'', form of endocytosis that allows cells to obtain molecules dissolved in fluids
70
What is phagocytosis?
''cell eating'', form of endocytosis that allows cells to obtain solids
71
How does surface area matter?
the greater the surface area to volume, the more efficient cell transport
72
What are advantages of multicellularity?
- division of labour; specialized cells are more efficient together
- size; more cells together
- interdependence; one cell dies, organism unaffected
73
What are the disadvantages of multicellularity?
-complex systems; need many specialized cells
- need more energy
-takes longer to reproduce
74
What are the plant organ systems?
1) shoot system- stem, leaves, buds, flowers, fruit; absorbs CO2 and releases O2
2) Root system- root and root hairs; absorb water and minerals from soil
75
What is mitosis?
Cell division for size and repair
76
What are meristems?
clusters of specialised cells where mitosis occurs
77
What are the specialised types of plant tissue?
1) Dermal (epidermis) tissue- outer layer of cell covering all non-woody platns; responsible for gas exchange and discrease protection
2) Ground tissue- majority of plant under epidermis; provides strength and support
3) Vascular Tissue- inside; transport of materials
78
What is the cuticle?
Waxy coating that prevents water loss and protects against micro organisms
79
What do dermal tissue in the root do?
Nutrient uptake
80
What do guard cells do?
controls stomata (open stomata when guard celll turgid/swollen)
81
What does the stomata do?
Allows gas exchange to occur via diffusion
82
What is transpiration?
Occurs when stomata is open; plant evaporation
83
What is turgor pressure?
Decreases when plant is dehydrated, shrink guard cells to close stomata and save water
84
What is the mesophyll?
Specialised layer of cells between upper and lower epidermis
85
What are palisade cells?
Site of photosynthesis
86
What are spongy cells?
Site of gas exchange
87
What does ground tissue in roots do?
Stores water and food
88
What does the phloem control?
moves sucrose and other dissolved sugars from leaves to stems and roots
89
What does the xylem control ?
Moves water and dissolved minerals from roots to stem and leaves
90
Other differences of xylem and phloem?
- xylem has no end walls, phloem has end walls (sieve plates)
- xylem is one way, phloem is two way
- xylem's outer cells aren't living, phloem's outer cells living but need support
91
What is a transpiration pull?
Water is transported up the xylem; possible by its cohesives nad adhesives properties (continuous column of water because they stick to each other and follow up)
92
What is the pressure flow theory?
Glucose is transported up and down the phloem due to pressure created by difference in water concentration in phloem and water in xylem ducts
93
What is tropism?
Plants react to stimuli and as a result grows in a specific direction
94
What is positive tropism?
growth of plant towards stimulus
95
What is negative tropism?
growth of plant away from stimulus
96
What is phototropism?
growth of plant in response to light (stem is positive, root is negative)
97
What is gravitropism?
growth of plant in response to gravity (stem is negative, root is positive)
98
What is auxin?
type of hormone controlling phototropism
99
How do plants communicate?
The symbiotic relationship between trees and fungi (mycorrhizal) create an underground communication network
