BIO 112 - GENERAL BIOLOGY I Flashcards
(238 cards)
1
Q
What are the 5 steps of the scientific method?
A
- Make observation
- Develop hypothesis
- Run experiment
- Analyze results
- Draw conclusions
2
Q
It’s winter and I’m growing spinach indoors. I want the plants to produce as much as possible. I normally water them twice a week but I’m thinking that if I water them 4 times a week, they will become bigger plants. So I’ll try both watering schedules and see what happens. List the variables:
A
Independent: amount of water
Dependent: amount of spinach produced
Standardized: growing conditions (fertilizer, sunlight, etc.)
3
Q
Define element.
A
Pure substance
4
Q
Define atom.
A
The smallest unit of a pure substance
5
Q
Define ion.
A
Atom with a positive or negative charge
6
Q
What is a cation and how is it formed?
A
Atom with a positive charge - it has lost an electron
7
Q
What is an anion and how is it formed?
A
Atom with a negative charge - it has gained an electron
8
Q
What happens regarding electrons in an ionic bond?
A
Electron transferred from one atom to another
9
Q
What happens regarding electrons in a nonpolar covalent bond?
A
Electrons shared equally
10
Q
What happens regarding electrons in a polar covalent bond?
A
Electrons shared unequally
11
Q
Define electronegativity and explain its role in determining what chemical bonds occur.
A
The ability for an atom to attract electrons. If the electronegativity difference between 2 atoms is
small, it forms a nonpolar bond. If it is large, it forms an ionic bond. Moderate differences form a
polar bond.
12
Q
Describe why one end of a water molecule carries a slightly negative charge and the other carries a slightly positive charge.
A
Oxygen pulls harder on electrons than hydrogen
13
Q
Which end carries the negative charge and which end carries the positive charge?
A
Oxygen - negative
Hydrogren - positive
14
Q
Define hydrogen bonds.
A
Occurs when the partial negatively-charged end of one polar molecule lines up with the partial positively-charged end of a different polar molecule
15
Q
Water is cohesive. Define cohesion.
A
Water molecule linked to other water molecules with hydrogen bonds
16
Q
Water is adhesive. Define adhesion.
A
Water molecule linked to other polar molecules with hydrogen bonds
17
Q
Why is water an excellent solvent?
A
Water is polar, so the positive side of a polar or ionic compound is attracted to the oxygen side of water, and the negative side of the compound is attracted to the positive side of water. This is why polar or ionic substances dissolve in water.
18
Q
Define hydrophilic and explain the chemistry involved.
A
Dissolves in water. Charged water molecules attracts charged polar or ionic molecules
19
Q
Define hydrophobic and explain the chemistry involved.
A
Doesn’t dissolve in water. Charged water molecules repel uncharged nonpolar molecules
20
Q
Define carbon skeleton.
A
Forms the framework of the molecule
21
Q
Define functional group.
A
Gives the molecule a specific function
22
Q
Define monomer.
A
A molecular building block. Monomers join to make polymers.
23
Q
Define polymer.
A
A molecule made up of two or more monomers
24
Q
What is dehydration synthesis?
A
Process that produces water during the chemical bonding of a monomer and a polymer
25
What is hydrolysis?
Water is added to a polymer in order to split off a monomer
26
List two different energy storage carbohydrates and write whether they are found in plants or animals.
Starch is found in plants
Glycogen is found in animals
27
List two different carbohydrates that provide structural support and write whether they are found in plants or animals.
Cellulose is found in plants
Chitin is found in animal exoskeletons and fungi
28
Why are polysaccharides usually hydrophilic?
Because they are polar
29
Fats are composed of...
glycerol and 3 fatty acids
30
What is the main function of a fat?
Fats store energy
31
Are fats hydrophobic or hydrophilic? Why?
Hydrophobic
They have non polar bonds
32
Phospholipids are composed of a head and tail that contain...
Head: glycerol and a phosphate group
Tail: 2 fatty acids
33
Is a phospholipid head hydrophilic or hydrophobic? Why?
Hydrophilic
The phosphate group carries a negative charge
34
Is a phospholipid tail hydrophilic or hydrophobic? Why?
Hydrophobic
It has non polar bonds
35
What is the function of a steroid?
Steroids are chemical messengers
36
Proteins are composed of...
amino acid monomers
37
What are the 6 functions of proteins? Describe them.
1. Signaling - sends and receives chemical messengers
2. Transport - proteins move oxygen and carbon dioxide through the body
3. Structure - ligaments join bone to bone; tendons join muscle to bone
4. Protection - skin protects the body from infection and from drying out
5. Movement - muscles are made out of protein
6. Defense - proteins include antibodies of the immune system
38
How are the phospholipid molecules oriented within a phospholipid bilayer?
Hydrophobic tails point toward center of the membrane, hydrophilic heads point toward cytoplasm and cell exterior
39
Describe how phospholipid chemistry controls what moves through the membrane.
Since the center of the membrane is hydrophobic, only hydrophobic molecules can pass freely through the membrane
40
List molecules that can easily pass through the membrane.
Any molecule whose atoms are linked with non polar bonds
41
List molecules that cannot pass through the membrane without help.
Polar or ionic molecules
42
What is the help that allows these molecules to pass through a membrane?
They travel through protein channels, not directly through the membrane
43
What role does a concentration gradient play regarding the movement of molecules across a cell membrane?
It provides the energy necessary to make molecules move from high to low concentration
44
Explain the difference between active and passive transport in terms of energy and concentration gradients.
Passive transport: concentration gradient provides energy to move molecules from high to low concentration
Active transport: cell provides energy to move molecules against the concentration gradient
45
Simple diffusion across a cell membrane:
What type of molecules are transported?
Molecules with non polar bonds
46
Simple diffusion across a cell membrane:
Can molecules move directly through a cell membrane? Why or why not?
Yes, they are hydrophobic, same as the cell membrane
47
Simple diffusion across a cell membrane:
Do molecules move up or down the concentration gradient?
Down
48
Simple diffusion across a cell membrane:
Is this a form of passive or active transport?
Passive
49
Osmosis across a cell membrane:
What type of molecules are transported?
Water
50
Osmosis across a cell membrane:
Can molecules move directly through a cell membrane? Why or why not?
No, the hydrophobic cell membrane repels the polar, hydrophilic water molecules
51
Osmosis across a cell membrane:
Do molecules move up or down the concentration gradient?
Down
52
Osmosis across a cell membrane:
Is this a form of passive or active transport?
Passive
53
Facilitated diffusion across a cell membrane:
What type of molecules are transported?
Molecules with polar or ionic bonds
54
Facilitated diffusion across a cell membrane:
Can molecules move directly through a cell membrane? Why or why not?
No, the hydrophobic cell membrane repels the polar, hydrophilic molecules. They can only move through protein channels.
55
Facilitated diffusion across a cell membrane:
Do molecules move up or down the concentration gradient?
Down
56
Facilitated diffusion across a cell membrane:
Is this a form of passive or active transport?
Passive
57
Describe the difference between a hypotonic, hypertonic, and isotonic environment.
Hypotonic: : Environment surrounding the cell is less concentrated than the cell. Water moves into the cell.
Isotonic: Concentration is the same inside and outside of the cell. No net water movement.
Hypertonic: Environment surrounding the cell is more concentrated than the cell. Water moves out of the cell.
58
Explain what happens to a blood cell and to a plant cell when each is placed in a hypotonic solution. Also explain why this happens to each type of cell.
In both cases, water moves into the cells. Plants have cell walls, so they can hold a lot of water pressure without bursting. But animal cells only have a cell membrane, and an influx of water can cause the cell to burst and die.
59
List the two parts of the cell theory and explain what basic question the cell theory can’t answer.
- Cells are the basic units of life and all cells come from other cells
- It can't explain the origin of life
60
List three functions essential to all life that prokaryotes conduct.
Form the base of every food web, make nitrogen available to all organisms, produce global recycling of nutrients and carbon through decomposition
61
List prokaryotic and eukaryotic organisms.
Prokaryotic: bacteria, archaea
Eukaryotic: animals, plants, fungi, protists
62
What 4 things are found in both prokaryotic and eukaryotic cells?
- Nucleic acids (DNA & RNA)
- Cell membrane
- Ribosomes
- Cytoplasm
63
List the differences between plant and animal cells.
Plants have cell walls, large central vacuoles, and chloroplasts
64
Describe how endosymbiosis provides a possible explanation for the evolution of eukaryotic cells.
Eukaryotic cells originated when archaea cells engulfed bacteria and those bacteria became part of the archaeal cell. The first eukaryotes were protists with mitochondria - some of these cells engulfed photosynthetic bacteria which became chloroplasts in algae and plants
65
Organelles:
What is the function of a nucleus?
Control center of the cell
66
Organelles:
What is the function of a vacuole?
Location of storage materials
67
Organelles:
What is the function of a ribosome?
Location of protein synthesis
68
Organelles:
What is the function of a chloroplast?
Location where photosynthesis occurs
69
Organelles:
What is the function of a mitochondria?
Location of energy production
70
Organelles:
What is the function of a lysosome?
Recycling center of the cell
71
Organelles:
What is the function of the Golgi appratus?
Modifies membrane-embedded proteins
72
Describe the difference between potential and kinetic energy.
Potential: has the potential to move or do work
Kinetic: energy associated with movement
73
Most organisms get energy from food. Where exactly is the energy located in food?
It is stored in chemical bonds holding glucose atoms together
74
Describe the path of energy from the sun until it reaches a form of energy that we can use. Include autotrophs and heterotrophs in your answer.
Autotrophs capture solar energy during photosynthesis and transfer it to the chemical bonds that hold glucose together. Heterotrophs catabolize glucose and transfer the energy that is released when the chemical bonds are broken into ATP.
75
Do these metabolic processes link or break chemical bonds, use hydrolysis or dehydration synthesis, and store or release energy?
- Anabolic
- Catabolic
- Exergonic
- Endergonic
- Anabolic: link, dehydration synthesis, store
- Catabolic: break, hydrolysis, release
- Exergonic: break, hydrolysis, release
- Endergonic: link, dehydration synthesis, store
76
Draw an exergonic and endergonic energy diagram and know which one is anabolic and which is catabolic.
- Exergonic & catabolic, starts high and ends low
- Endergonic & anabolic, starts low and ends high
77
All organisms use ATP as a source of energy to fuel metabolic reactions. How does ATP store and release energy?
ATP (with 3 phosphates) stores energy by adding a terminal phosphate group to ADP (two phosphates). ATP releases energy by removing the terminal phosphate from ATP to make ADP.
78
What is energy coupling and how does it occur?
Energy coupling is when ATP hydrolysis (the removal of the terminal phosphate group) is linked to another process. This occurs when ATP transfers the phosphate group to another molecule.
79
Explain how exergonic/catabolic and endergonic/anabolic reactions influence the ADP-ATP cycle.
ATP becomes ADP and provides energy for endergonic/anabolic reactions, the energy to transform ADP into ATP comes from catabolic/exergonic reactions.
80
Enzymes are catalysts. What is the definition of a catalyst as it applies to metabolism?
A catalyst lowers the amount of energy that is needed for a metabolic reaction occur.
81
In the lock and key theory of enzymes and substrates, what is the lock and what is the key?
Enzyme - lock
Substrate - key
82
Describe the function of an allosteric site on an enzyme.
It turns off (inhibits) or turns on (activates) an enzyme by changing the active site shape when something binds to the allosteric site.
83
Describe the difference between competitive and allosteric inhibition.
- Competitive inhibition: a substrate binds to the active site and blocks the normal substrate from binding
- Allosteric inhibition: something binds to the allosteric site, which changes the active site shape so the normal substrate can’t bind to it
84
What is the default and altered condition of allosteric inhibition? Allosteric activation?
- Allosteric inhibition: default on, altered off
- Allosteric activation: default off, altered on
85
Write the chemical equation for aerobic cellular respiration and list which substrates are oxidized, which are reduced, and the products each substrate becomes.
Glucose + oxygen —> CO2 + H2O
Glucose is oxidized to become CO2
Oxygen is reduced to become H2O
86
Define redox reaction.
Reaction that transfers an electron from one molecule to another
87
Define oxidation.
Process where a molecule loses an electron
88
Where does glycolysis occur?
In the cytoplasm
89
What is the role of NAD+ in glycolysis?
NAD+ gets reduced to NADH and carries electrons to the electron transport chain
90
Define reduction.
Process where a molecule gains an electron
91
What process produces ATP during glycolysis?
Substrate-level phosphorylation
92
List the 3 starting materials for glycolysis and the final products.
Starting substrates: glucose, ADP, NAD+
Ending products: pyruvate, ATP, NADH
93
List the molecules that enter and leave pyruvate oxidation.
Enter: pyruvate, NAD+
Exit: acetyl-coA, CO2, NADH
94
List the starting and ending molecules in the citric acid (Krebs) cycle.
Starting: acetylene-coA, NAD+, ADP, FAD
Ending: CO2, NADH, ATP, FADH2
95
What process produces ATP during the citric acid cycle?
Substrate-level phosphorylation
96
Describe the process of chemiosmosis.
- ___ carried by ___ are dumped into the ___.
- As they move down the chain, their ___ is used to build a ___.
- The ___ pass through ___ to produce ___.
- ___ end up ___ oxygen to ___.
Electrons carried by NADH are dumped into the ETC. As they move down the chain, their energy is used to build a H+ gradient. The protons pass through ATP synthase to produce ATP. Electrons end up reducing oxygen to water.
97
Label the mitochondria structures that are involved in aerobic cellular respiration and list what processes occur at or in these structures.
Inner membrane: electron transport chain
Matrix: pyruvate oxidation and citric acid cycle
Intermembrane space: H+ gradient
98
What is oxidative phosphorylation?
Chemiosmosis where oxygen is the terminal electron acceptor
99
Explain the difference between substrate-level and oxidative phosphorylation.
- Transfer of energy
- S-L: ___ is synthesized with a ___ transferred from a ___ to ___.
- O: ___ is synthesized when a ___ dissipates through ___.
Substrate-level phosphorylation: direct transfer of energy - ATP is synthesized with a phosphate group transferred from a molecule to ADP
Oxidative phosphorylation: indirect transfer of energy - ATP is synthesized when a proton gradient dissipates through ATP synthase
100
Fermentation does not produce ATP so why do cells conduct fermentation?
It oxidizes NADH to NAD+ and the NAD+ is needed in glycolysis to produce ATP
101
Describe what happens during lactic acid fermentation and alcoholic fermentation.
Lactic acid fermentation: pyruvate is oxidized, producing NAD+ and lactic acid
Alcoholic fermentation: pyruvate is oxidized, producing NAD+, CO2, and ethanol
102
List 3 benefits associated with food fermentation.
- Adds nutrients, flavor, and vitamins
- Makes food more digestible by breaking down fibers
- Preserves food by creating an acidic environment that food spoilage bacteria can’t live in
103
What is the terminal electron acceptor and the relative amount of ATP produced for the following:
- Aerobic respiration
- Anaerobic respiration
- Fermentation
- Oxygen; high
- Nitrate, sulfate, or CO2; medium
- Organic molecules; none
104
Write the chemical equation for photosynthesis and list which substrates are oxidized, which are reduced, and the products each substrate becomes.
CO2 + H2O —> glucose + oxygen
CO2 is reduced to become glucose
H2O is oxidized to become oxygen
105
Identify the chloroplast structures that are involved in photosynthesis and list what process occurs at each of these structures.
Thylakoid membrane: light reactions
Lumen: H+ gradient
Stroma: carbon reactions
106
Which colors of the spectrum does chlorophyll absorb, why are plants green?
Absorbs red and blue, reflects green
107
List two differences between oxidative phosphorylation and photophosphorylation.
Oxidative: oxygen is the terminal electron acceptor and energy comes from breaking glucose chemical bonds
Photo.: NADP+ is the terminal electron acceptor and energy comes from the sun
108
Describe what happens in a photosystem.
- ___ within the light-harvesting complexes ___ light and pass ___ to a special pair of ___ molecules in the ___.
- The absorbed ___ causes an ___ from ___ to be transferred to the ___.
- The ___ that are transferred are replaced with ___ from ___.
Pigments within the light-harvesting complexes absorb light and pass energy to a special pair of chlorophyll a molecules in the reaction center. The absorbed energy causes an electron from chlorophyll a to be transferred to the ETC. The electrons that are transferred from chlorophyll a are replaced with electrons from water.
109
Describe chemiosmosis in photosynthesis including its important components.
- ___ from ___ moving through the ___ is used to build a ___ in the ___.
- The ___ pass through ___ to produce ___.
Energy from electrons moving through the ETC is used to build a H+ gradient in the thylakoid space. The protons pass through ATP synthase to produce ATP.
110
Trace the path of electrons during the light phase of photosynthesis.
Water —> photosystem II —> electron transport chain —> photosystem I —> NADP+
111
Describe how the atoms that make up water are used in the light reactions.
Oxygen: not used (given off as a waste product)
Hydrogen: helps build the H+ gradient
Electrons: replaces electrons that leave photosystems
112
Briefly describe what happens during the three steps of the Calvin cycle. Make sure you know what order these processes occur in.
Carbon fixation (aka carboxylation): CO2 attached to RuBP by rubisco
Reduction: ATP and NADPH supply energy to be locked into chemical bonds
Regeneration: RuBP is regenerated
113
Define the central dogma.
DNA -> transcription -> RNA -> translation -> protein
114
What is the role of DNA (central dogma)?
stores information
115
What is the role of RNA (central dogma)?
copies information
116
What is the role of protein (central dogma)?
the product of gene expression
117
What is the role of transcription (central dogma)?
a mRNA copy of a DNA gene is made
118
What is the role of translation (central dogma)?
mRNA works with tRNA to produce a protein at a ribosome
119
List the four nitrogenous bases. Which pairs are complementary?
adenine, guanine, cytosine, thymine
A-T, C-G
120
Write the complementary DNA sequence for this strand of DNA:
5' CTAATGCTAGATACGA 3'
3' GATTACGATCTATGCT 5’
121
DNA synthesis occurs in a 5' to 3' direction. Explain what this means and why synthesis occurs in this direction and not the opposite direction.
The 5’ end of a new nucleotide links to the 3’ end of the existing DNA molecule. This occurs because the 5’ end has phosphate groups that provide the energy necessary to create the chemical bond.
122
Describe DNA structure.
The DNA molecules is a double-helix with strands in an antiparallel orientation. The bases are aligned in the center and joined with hydrogen bonds.
123
Describe semi-conservative DNA replication.
Each DNA molecule contains one parent template strand and one newly-synthesized daughter strand.
124
What is the order of the processes that occur during DNA replication?
- Helicase
- Binding proteins
- Primase
- DNA polymerase
- Ligase
125
What is the function of helicase (DNA replication)?
unwinds and separate DNA strands
126
What is the function of binding proteins (DNA replication)?
hold separated DNA strands apart (keeps them separated)
127
What is the function of primase (DNA replication)?
adds RNA primer to DNA
128
What is the function of DNA polymerase (DNA replication)?
adds complementary DNA bases to synthesize a new DNA molecule
129
What is the function of ligase (DNA replication)?
links Okazaki fragments
130
Explain the difference in daughter strand synthesis on the leading and lagging strands of template DNA.
leading strand has continuous synthesis, lagging strand has discontinuous synthesis
131
What are Okazaki fragments?
sections of DNA made during discontinous synthesis
132
What is the main difference in function between DNA and RNA?
DNA stores information
RNA copies information and uses it to make a protein
133
List four differences in structure between DNA and RNA.
- DNA is large, RNA is small
- DNA is double-stranded, RNA is single-stranded
- DNA has thymine, RNA has uracil
- DNA has deoxyribose sugar, RNA has ribose sugar
134
What happens during transcription?
Where does it occur?
a DNA gene is copied into a RNA molecule, happens in the nucleus
135
Write the RNA sequence that is complementary to this DNA sequence:
5’ TTGACCGATCGATAGCTTGACAT 3'
3’ AACUGGCUAGCUAUCGAACUGUA 5’
136
What are the 3 types of RNA? What are their functions?
mRNA (messenger): makes a copy of a DNA gene
rRNA (ribosomal): combines with proteins to make a ribosome
tRNA (transfer): brings amino acid to ribosome and attaches it to the protein that is being made
137
What happens during translation?
Where does it occur?
ribosome moves along mRNA and tRNA brings new amino acids to a protein that is being made
cytoplasm
138
What is a codon?
Where is it located?
a sequence of 3 RNA bases that code for a specific amino acid
located on mRNA
139
What is an anticodon?
Where is it located?
3 RNA bases that are complementary to codon bases
located on tRNA
140
List the types of mutations. (5)
- Silent
- Missense
- Nonsense
- Insertion
- Deletion
141
What happens during silent mutation?
Is it a point or frameshift mutation?
changes DNA but NOT amino acid
point
142
What happens during missense mutation?
Is it a point or frameshift mutation?
changes DNA AND amino acid
point
143
What happens during nonsense mutation?
Is it a point or frameshift mutation?
codes for a stop codon
point
144
What happens during insertion?
Is it a point or frameshift mutation?
inserts an extra base into DNA and changes all following amino acids
frameshift
145
What happens during deletion?
Is it a point or frameshift mutation?
deletes a DNA base and changes all following amino acids
frameshift
146
What is the amino acid sequence of the protein that will be translated on the ribosome using this mRNA sequence:
5’-CCUGAUGGGUCAACGCUUAUGAG-3’
Always start with AUG
5'-CCUG AUG (Met) GGU (Gly) CAA (Gln) UUA (Leu) UGA (Stop) G-3'
147
What type of mutation occurs when the 8th base is changed from G to U?
5’-CCUGAUGGGUCAACGCUUAUGAG-3’
GGU changes to UGU, Gly changes to Cys, missense mutation
148
Define somatic cell. Is it diploid or haploid?
any cell in the body except for a gamete - the cell is diploid (it contains two copies of every gene, one from each parent)
149
Define gamete cell. Is it diploid or haploid?
reproductive egg or sperm cells - the cell is haploid (it contains one copy of every gene)
150
Describe the difference between mitosis and meiosis.
- mitosis starts with one diploid cell and produces two diploid cells
- meiosis starts with one diploid cell and produces four haploid cells
151
What is the order of the phases of interphase? (4)
- G1 phase
- G0 phase
- S phase
- G2 phase
152
What happens during G1 phase?
initial cell growth after cell division
153
What happens during G0 phase?
no cell growth but cell is metabolically active; nerve and heart cells remain in this phase because they don't reproduce
154
What happens during S phase?
DNA is replicating to make 2 copies; one for each cell when the cell divides
155
What happens during G2 phase?
cell prepares for mitosis
156
What is the order of the phases of mitosis? (6)
- prophase
- prometaphase
- metaphase
- anaphase
- telophase
- cytokinesis
157
What happens during prophase?
chromosomes condense
158
What happens during prometaphase?
nuclear membrane starts to break down
159
What happens during metaphase?
chromosomes line up in the middle of the cell
160
What happens during anaphase?
chromosomes move to opposite ends of the cell
161
What happens during telophase?
nuclear membrane reforms and chromosomes start to decondense
162
What happens during cytokinesis?
one cell divides into two cells
163
List 3 advantages of asexual reproduction.
List 2 disadvantages.
A: rapid reproduction, no mates required, low energy investment
D: low genetic diversity, low ability to adapt to natural selection
164
List 2 advantages of sexual reproduction.
List 2 disadvantages.
A: high genetic diversity, greater chance of adaptation to natural selection
D: large energy investment, requires more time to produce offspring
165
Define allele.
version of a gene; each organism has two alleles for every gene (one from each parent)
166
Define genotype.
alleles that an organism has
167
Define homozygous alleles.
both alleles are the same
homozygous dominant - two dominant alleles
homozygous recessive - two recessive alleles
168
Define heterozygous alleles.
each allele is different (one dominant, one recessive)
169
Define phenotype.
the product of gene expression
170
Describe the differences between complete dominance, incomplete dominance, and codominance.
Complete: 3 possible genotypes, 2 possible phenotypes
Incomplete: 3 possible genotypes, 3 possible phenotypes
Codominance: both alleles are dominant, 6 possible genotypes, 4 possible phenotypes
171
Explain evolution using the terms population and natural selection.
evolution is a change in population genetic variability over time in response to natural selection
172
List 2 things that cause genetic variation in populations.
random mutation
sexual reproduction
173
Define natural selection.
individuals with traits that are favorable are more likely to survive and produce offspring than those who do not have those traits
174
What happens to gene frequencies over time?
gene frequencies change over time as populations adapt to natural selection
175
What happens if a population does not contain favorable genes/traits?
it may go extinct
176
How can genetic variability in traits lead to a differential reproduction?
organisms with traits that provide a selective advantage to natural selection are more likely to survive, reproduce, and pass those genes on to the next generation
177
Define fitness in terms of evolution.
What do higher fitness and lower fitness mean?
fitness refers to the ability to survive and reproduce
higher fitness = greater chance of survival and reproduction
lower fitness = lower chance
178
Describe the difference between microevolution and macroevolution.
Micro: changes in population genetic variability that do not lead to speciation
Macro: long-term, large-scale changes that lead to speciation (new species)
179
Describe epigenetics and its impact on evolution.
epigenetics is when environmental factors (pollutants, drugs, stress, diet) can activate or deactivate normal gene expression
epigenetic changes can be passed on to offspring, rendering them more susceptible to certain diseases or conditions (diabetes) than offspring who were born without parental epigenetic changes
180
Describe the 3 types of horizontal gene transfer and their impact on evolution.
- transduction: living bacteria take in genes from dead and decaying bacteria
- conjugation: genes are transferred from one living bacteria to another
- transduction: viruses transfer genes from one bacteria to another
*horizontal gene transfer is the primary mechanism responsible for the drastic rise in antibiotic resistance
181
Describe how endosymbiosis occurred and its impact on evolution.
endosymbiosis occurred when two free-living bacteria merged into one organism
this process produced the origin of all eukaryotes (animals, fungi, plants, protists)
182
Explain how humans can genetically modify organisms with recombinant DNA technology and the impact on evolution.
a gene of interest is transferred to a plasmid and the plasmid is inserted into bacteria or plants
this process has allowed use to genetically modify corps to resist pests and herbicides, and bacteria to produce human insulin
183
Describe CRISPR-Cas9 technology and its impact on evolution.
CRISPR-Cas9 technology can identify a specific DNA sequence, cut the DNA strands, and insert any gene into the genome
it has the potential to cure conditions such as sickle cell anemia, cancer, cardiovascular diseases and is the main mechanism used to bring back organisms that are currently extinct
184
List 5 different ways that humans use plants.
1. food
2. shelter
3. raw materials (for paper and explosives)
4. fossil fuels
5. fibers for clothing
185
List 5 ways plants modify the environment.
1. build healthy soil by providing organic matter
2. plant roots hold soil and prevent erosion
3. plants retain water; wetland plants provide flood control
4. moderate the local climate by providing shade and adding humidity to the air with transpiration
5. provide noise control
186
List the 3 adaptations that define the major groups of plants living today.
1. non-vascular plants
2. vascular plants
3. seeds
187
Describe the non-vascular plant adaptation.
the first plants to colonize land
needed to live in moist areas because the only way they could transport water and nutrients was with osmosis and diffusion
188
Describe the vascular plant adaptation.
allowed plants to become taller and live in drier areas because they could obtain water and nutrients from below the soil surface and transport it throughout the plant
189
Describe the seed adaptation.
provided plant embryos with protection, food to help with germination, and a way to disperse to new areas
190
Describe the obtaining water and nutrients plant adaptation.
- roots absorb water and minerals from soil
- desert flowers can stay dormant for months, only coming to life when it rains
191
Describe the stomata plant adaptation.
pores in leaves that allow plants to regulate water loss and gas exchange
192
Describe the defense plant adaptation.
- spines and thorns protect plants from predators
- poison ivy and poison oak have toxins that give predators a painful itchy rash
- resin produced by plant can be toxic to herbivore, glue mouthparts together, engulf and suffocate, and seal off herbivore damage
- trichomes produce a sweet compound that when eaten by herbivores produces a volatile chemical that attracts herbivore predators
193
Describe plant adaptations in the tundra.
Small plants grow close to the ground for warmth and have dark-colored flowers to absorb heat from the sun
194
Describe plant adaptations in the boreal forest.
Needles are not shed to retain nutrients and are waxy to retain water
195
Describe plant adaptations in the temperate forest.
Nutrients are transferred from leaves back to the plant before they fall off during autumn.
Leaves are shed to prevent damage to them from freezing
196
Describe plant adaptations in the grassland.
Plants have flexible stems to bend in the wind, narrow leaves lose less water than broad leaves, and deep roots to regrow after a fire
197
Describe plant adaptations in the desert.
Waxy thick skin conserves water, shallow roots absorb rainfall before it evaporates
198
What is the difference between meristem tissue and permanent tissue?
meristem - can differentiate into any type of tissue
permanent - has differentiated into a specific type of tissue
199
Describe the differences between apical, lateral, and intercalary meristem tissue.
apical - taller and longer plant growth (stem, roots)
lateral - wider plant growth (tree trunks getting thicker)
intercalary - growth that becomes plant leaves
200
List 2 types of dermal tissue and the function of each.
epidermis - covered with a waxy cuticle, protects against infection and drying out
guard cells - surround stomata, allow for gas exchange
201
List 3 types of ground tissue.
- parenchyma
- collenchyma
- sclerenchyma
202
List 2 types of vascular tissue and the function of each.
xylem - transports water and minerals
phloem - transports dissolved organic compounds (sugars)
203
Describe the movement of water and minerals in xylem.
- osmosis (water enters roots when roots have higher concentration of solutes than surrounding soil)
- capillary action up through stems (combo of adhesion and cohesion)
- transpiration (exits through stomata in leaves)
204
Water has a ___-way flow through the plant from ___ through ___.
The force to pull water through a plant is because it is a ___ ___ of water and as each molecule exits via ___, the entire ___ moves upward.
one-way, from ground through stomata
continuous column, transpiration, entire column
205
Describe the movement of dissolved organics in phloem.
- dissolved organics (sugars) are pushed from one place to another according to a source/sink model
- source: the sugars are produced in leaves during photosynthesis
- they are actively transported into phloem and exit at high concentration
- water flows in via osmosis, increases concentration more
- sugars are removed where they're needed to support growth at sinks (flowers, roots, stems)
- when sugars are removed, concentration lowers and water exits
206
Source/sink model:
Sugars are pushed from ___ to ___ and can flow in ___ direction in a plant.
source to sink, any direction
207
What is the difference between anatomy and physiology?
anatomy - study of bone structure
physiology - study of how the body functions
208
List the organization of animal structures from simplest to most complex. (7)
atom -> molecule -> organelle -> cell -> tissue -> organ -> system
209
Define epithelial tissue and its function.
tissue consisting of closely packed cells that protect by covering the body and lining its organs and cavities
210
Define connective tissue, list 6 different connective tissue and their functions.
tissue that binds and supports other tissues
tendons - attach muscle to bone
ligaments - attach bone to bone
cartilage - protects joints
blood - transports nutrients, waste, oxygen
adipose - stores energy
loose connective - connects skin to underlying tissue
211
Define muscle tissue, list 3 different muscle tissue types and their functions.
tissue that aids in movement
cardiac - pumps blood
smooth - involuntary movement (digestion, etc.)
skeletal - voluntary movement
212
Define nervous tissue and its function.
tissue that senses stimuli and transmits information
213
Explain the connection between tissues and organs.
organs are made up of different types of tissues
214
List the 9 organ systems.
- circulatory
- digestive
- nervous
- urinary
- respiratory
- integumentary
- skeletal
- muscular
- lymphatic and immune
215
Describe the function of the circulatory system.
transports oxygen, nutrients, and metabolic wastes
216
Describe the function of the digestive system.
breaks down foods and absorbs nutrients
217
Describe the function of the nervous system.
detects stimuli, transmits information, and directs responses
218
Describe the function of the urinary system.
removes waste, regulates blood chemistry, pH, and water balance
219
Describe the function of the respiratory system.
provides gas exchange (carbon dioxide and oxygen)
220
Describe the function of the integumentary system.
protects against infection and drying out
221
Describe the function of the skeletal system.
provides support for body and a framework for muscle movement
222
Describe the function of the muscular system.
provides movement
223
Describe the function of the lymphatic and immune system.
protects against infection and cancer
224
What is the role of homeostasis?
maintains internal equilibrium and optimal conditions
225
Explain how negative feedback works to maintain homeostasis and the 4 steps.
negative feedback produces activity that acts in the opposite direction of whatever is changing the ideal state
1) a change (stimulus) in the environment occurs
2) the change is detected, a signal is sent to a control region
3) the control region directs a response designed to counteract the stimulus
4) the response returns internal conditions to normal
226
What is the difference between endotherms and ectotherms? What are the advantages and disadvantages of each?
endotherms - body temperature is regulated by metabolism (warm-blooded), A: greater habitat and foraging range, D: requires more energy to maintain body temp
ectotherms - body temperature is regulated by environment (cold-blooded), A: requires less energy to maintain body temp, D: reduced habitat and foraging range
227
List 3 types of habitat loss and describe how each one impacts species diversity.
Habitat destruction - habitat is eliminated
Habitat degradation - quality of habitat is reduced (pollution or invasive species)
Habitat fragmentation - habitat is broken up into smaller patches
228
How does habitat fragmentation affect the organisms that live in the habitat?
Fragments are harder to repopulate if needed and can lead to extinction
229
Describe the impact of deforestation on natural systems and organisms. (3)
- Makes climate drier due to lack of forest transpiration
- Increases erosion and reduces soil fertility
- Loss of potential drugs and medicines
230
Describe the impact of invasive species on natural systems and organisms. (1)
reduces biodiversity
231
What are some traits of successful invasive species? (4)
- rapid reproduction and growth
- able to tolerate wide range of environments
- widespread and high dispersal ability
- association with humans (often arrive via
human transportation)
232
What ecosystem conditions support ecosystem invasion?
Small habitat patches or disturbed (by humans) habitats
233
Describe the impact that agriculture has had on crop and livestock biodiversity. (1)
Has reduced crop and livestock biodiversity
234
Explain how pesticides lead to bioaccumulation.
- pesticides in water are absorbed by microscopic organisms, then eaten by increasingly larger prey
- the pesticide concentration increases as one moves up the food chain so that there are high concentrations found in top predators
235
Explain how water pollution leads to health problems.
Unsafe drinking water causes disease and kills almost 2 million people each year
236
Describe the functions of parenchyma. (4)
photosynthesis, food storage, wound repair, hormone secretion
237
Describe the functions of collenchyma. (2)
living cells, flexible support
238
Describe the functions of sclerenchyma. (2)
dead cells (wood), rigid support
