Biology MCAT Review Flashcards
1
Q
Bacilli
A
Rod shaped
2
Q
Conjugation
A
Integration of foreign material sexually, from the donor male to the recipient female
3
Q
Obligate aerobes
A
Bacteria which undergo aerobic processes and cannot survive without the presence of oxygen
4
Q
Facultative anaerobes
A
Bacteria which undergo anaerobic processes preferentially, but can undergo aerobic processes in the presence of oxygen
5
Q
How do eukaryotic cells replicate?
A
Through mitosis, leading to two identical daughter cells
6
Q
What is the F factor?
A
It is a sex factor in E coli
7
Q
What are some functions of a peroxisome?
A
It participates in breakdown of long chain fatty acids through Beta-oxidation, helps to synthesize phospholipids and contains enzymes for the pentose phosphate pathway
8
Q
What causes the death phase?
A
The ultimate depletion of resources in the population
9
Q
Transduction
A
Foreign DNA integration after infection by a virus
10
Q
What is a Gram+ cell wall composed of?
A
Thick layer of peptidoglycan and lipoteichoic acid
11
Q
What are endosomes?
A
Vesicles that transport cellular materials to the lysosomes, trans-golgi, or cellular membrane
12
Q
What is a Gram- cell wall composed of?
A
A thin layer of peptidoglycan
13
Q
What is the Endoplasmic reticulum?
A
It is comprised of interconnected contiguous membranes which originate at the nuclear envelope.
14
Q
What protein comprises microfilaments?
A
Actin
15
Q
What are organelles?
A
They are are membrane bound spaces within a eukaryotic cell that have unique functions
16
Q
What is the result of the exponential growth phase?
A
Quick growth and quickly diminishing resources
17
Q
Stroma
A
The supportive structure parts of an organ
18
Q
What form is genetic information present in the nucleus?
A
Genes are present within linear DNA, which is then wrapped around histone proteins to create separate chromosomes
19
Q
How can lysosomes trigger apoptosis?
A
Through autolysis - the purposeful release of enzymes into the cell
20
Q
What are two possible types of substrate the lysosome breaks down?
A
Cellular waste products and endocytic materials
21
Q
Columnar
A
Tall and thin
22
Q
Cuboidal
A
Cube like
23
Q
What do negative sense viruses need that positive sense viruses don’t?
A
RNA replicase
24
Q
What are prions?
A
Misfolded proteins which trigger protein misfolding on a larger scale, leading to lowered solubility and plaque formation
25
Why are viruses not considered living organisms?
They cannot reproduce on their own and they can use RNA as their genetic information
26
Does epithelial tissue typically contribute to the parenchyma or the stroma?
The parenchyma
27
What is necessary for Conjugation?
Sex factors which encode sex pilli
28
What is a basement membrane
It is the bottom layer of epithelium, comprised of connective tissue
29
What are viruses in the lysogenic cycle called?
Productive viruses
30
What are two characteristics of prokaryotic cells?
They are unicellular and do not have a nucleus
31
What specific organelles are comprised primarily from microtubules?
Cilia and flagella
32
What is an immune function of the peroxisome?
It presence in macrophages allows for the degradation of viral/bacterial pathogens
33
What is the function of intermediate filaments?
They are important to cell to cell adhesion, anchoring of the organelles/nucleus, and help maintain integrity of cytoskeleton
34
Transposons
Genetic elements that insert and remove themselves into genomes
35
What are episomes?
Genetic information contained within bacterial plasmids that may be integrated into the genome
36
Where do you find epithelial tissue?
Lining the outside of the body and its cavaties
37
What is a secondary function of the mitrochrondria?
It can trigger apoptosis through release of enzymes from the ETC
38
What is a plasmid?
A small circular form of DNA which is not part of the genome and is not required for survival
39
How are mitochondria and other organelles thought to have arisen?
By a prokaryote engulfing another prokaryote leading to a symbiotic relationship
40
What secondary structure is affected by prions typically?
Alpha helices are misfolded to beta pleated sheets
41
How are epithelium categorized?
Based on shape and number of layers
42
What is chemostaxis?
The ability to sense chemical stimuli and move towards/away from them
43
What are examples of modifications that can be made to a cellular product?
Addition of carbohydrates, phosphates, sulfates or signal sequences
44
What type of force are intermediate filaments resistant to?
Tension
45
Aerotolerant anaerobes
Bacteria which undergo anaerobic processes but can survive in the presence of oxygen
46
What are similarities between Eukaryotes and Archaea?
They have similar metabolic pathways and genes
47
What is the function of epithelial tissue?
To provide a barrier between the body and the outside world; it prevents pathogen invasion and desiccation
48
What are prokaryotes?
Single celled organisms with circular DNA and no membrane bound organelles
49
What is the purpose of a signal sequence?
It contains location information that helps route cellular products to the correct area
50
Spirilli
Spiral shaped
51
What are functions of the smooth ER?
Detoxification of certain drugs/poisons, synthesis of lipids, and transportation of proteins from the rough ER to the Golgi
52
How do we represent the growth of bacterial colonies?
The bacterial growth curve
53
What is the structure of centrioles?
9 triplets of microtubules with a hollow center
54
What are two characteristics of eukaryotic cells?
They have a true nucleus and can be unicellular or mulicellular
55
How does epithelial tissue look?
It appears as tightly connected cells which are also attached to a basement membrane
56
What is unique about the "9+2" structure?
It is only seen in Eukaryotic organelles of motility
57
What are the three components of the cytoskeleton?
Microfilaments, microtubules, and intermediate filaments
58
Squamous
Flat and scale like
59
Negative sense
Used to describe single stranded RNA viruses which need to have complementary strand transcribed prior to protein translation
60
What are kinetochores?
The complex of centrioles and chromosomes during the mitosis
61
How are bacteria and Archaea similar?
They both are single celled organisms that contain no nucleus, have circular DNA and divide by fission
62
What is the main function of the Golgi?
To modify and sort cellular products
63
What does it mean to be Hfr
It means high frequency of recombination -- cells that easily integrate sex factors into their genome
64
What are viral envelopes made from?
Phospholipids and proteins
65
What is the name of the microtubule structure within cilia and flagella?
"9+2" or an outside tube of 9 microtubule pairs with 2 microtubules within
66
What are 4 ways that bacterial genes are added extragenomically?
Transformation, Conjugation, Transduction and Transposons
67
What causes the stationary phase?
Limited resources which leads to equal growth and death rates
68
Cocci
Spherical
69
What does it mean when they say the mitochrondria are semi-autonomous?
They contain some of their own genes and replicate independently of the nucleus through binary fission
70
What are microtubules?
Hollow rods of tubulin which radiate throughout the cell
71
What is a primary function of microfilaments in specific cell types?
In muscle cells, it interacts with myosin to create force and contraction
72
What role do microfilaments play in cell replication?
They create the cleavage furrow in cytokinesis which allows one cell to split into two
73
What is the function of a plasmid?
Plasmids often confer advantages such as antibiotic resistance
74
What is the capsid made of?
Protein
75
What protein comprises intermediate filaments?
Intermediate filaments are a varied group of filamentous proteins. The composition is determined by cell and tissue type
76
Are enveloped or non-enveloped viruses stronger?
Non enveloped; enveloped viruses are susceptible to heat and detergents
77
What is connective tissue?
Tissue that exists to support the body and provide framework for other tissues
78
What is the intermembrane space of the mitochondria?
The region between the outer and inner mitochondrial membrane
79
What protein makes up flagella in bacteria?
Flagellin
80
What type of force are microfilaments resistant to?
Compression/fracture
81
Obligate anaerobes
Bacteria which undergo anaerobic processes and cannot survive in the presence of oxygen
82
What are functions of the rough ER?
It completes protein synthesis from RNA
83
What does the double membrane of the nucleus do?
It ensures separation of the cytoplastic and nuclear environment by providing selective two-way exchange. It also allows for separation of transcription and translation.
84
What role do microtubules play in cellular replication?
They comprise the centrioles which then organize and pull apart the mitotic spindle during mitosis.
85
What are virions?
Short, circular single stranded RNA that bind to RNA in host cells to silence genes
86
What is a consequence of lysosome dysfunction?
Cellular damage and apoptosis caused by accidental release of enzymes into the cytoplasm
87
Transformation
Integration of foreign genetic information into the host genome, often by uptake of foreign material after lysis
88
What are cristae important for?
Increasing surface area to hold more proteins in the ETC = more ATP creation
89
Pseudostratified epithelium
Appears multilayered but all cells are connected to the basement membrane = single layered
90
What are four main functions of the cytoskeleton?
It provides structure for the cell, it helps with transportation of cellular material, provides motility and is important for cellular replication/division
91
Does connective tissue typically contribute to the parenchyma or the stroma?
The stroma
92
What shape bacteria is the least likely to be pathogenistic?
Spirilli
93
What structural element do some but not all viruses have?
An envelope
94
What is the mitochrondria's most important function?
To create ATP using proton motive force established by the ETC.
95
Once a virus in the lysogenic cycle integrates into the genome, what is is called?
Prophage or provirus
96
What do the sex pilli do?
They help form the conjugation bridge which allows for genetic information to transfer between cells
97
What is the mitochrondrial matrix?
The region within the inner mitochondrial membrane
98
Simple epithelium
single layered
99
What color will Gram- bacteria appear after staining?
Pink
100
What are 5 differences between cell structure of eukaryotes and bacteria?
Eukaryotes have linear chromosomes organized by histones vs circular chromosomes with histone-like proteins, bacteria contain additional DNA in plasmids, Eukaryotic mitochrondria complete ETC versus the bacterial cell membrane, Eukaryotes have a more complex cytoskeleton, and Eukaryotes have a larger ribosome
101
Stratified Epithelium
Multi layered
102
Retroviruses
Enveloped single strand RNA viruses which use reverse transcriptase to synthesize DNA and integrate into host genome
103
What is the most important material of a peroxisome?
Hydrogen peroxide
104
What is unique about Archaea?
They are often extremophiles and use alternative energy sources
105
How is viral genetic information stored?
It can be present in small or large amounts, in circular or linear strands, single and double stranded, made from DNA or RNA
106
What are the phases of the bacterial growth curve?
Lag phase, log phase, stationary phase and death phase
107
Parenchyma
The functional parts of an organ
108
What are 3 functions of the bacterial cell wall?
Contains ETC, protects the cell and adds structure, and controls movement of solutes
109
What causes the lag phase?
It is the time needed to adjust to the environment and produce cellular machinery to make energy
110
What are centrosomes?
The area of the cell where centrioles are found
111
What color will Gram+ bacteria appear after staining?
Deep purple
112
What are types of connective tissues?
Bone, cartilage, blood, adipose, ligaments, tendons
113
What protein comprises microtubules?
Tubulin
114
What are the four tenants of cell theory?
All living things are comprised of cells. These cells are the basic functional unit of life. Cells arise only from preexisting cells and they carry genetic information in the form of DNA which is then passed from mother to daughter cell
115
What is the primary function of the lysosome?
To contain enzymes which break down many substrates
116
How do prokaryotes reproduce?
Binary fissure
117
What additional component is present in the envelope of a Gram- bacterium?
An outer membrane composed of phospholipids and lipopolysaccharides
118
What are cristae?
The foldings of the membrane within the mitochondria
119
What are viruses in the lytic cycle called?
Virulent viruses
120
What is the Golgi Apparatus?
It is comprised of stacked membrane bound sacs
121
What are the four types of tissue?
Epithelial, connective, muscle and nerve
122
Positive sense
Used to describe single stranded RNA viruses which can be directly transcribed into proteins
123
What is cytoplasmic/extranuclear inheritance?
The idea that some genes are passed on independently of the nuclear genes due to mitochondrial involvment
124
What are 2 characteristics of the nucleus?
It is bound by a double membrane and contains the genetic information of the cell
125
What are the integral components to a virus?
Genetic information and capsid
126
What does it mean for epithelium to be polarized?
It means that the composition/function of the lumen side of the cell is different than the opposite side
127
What region of the mitrochrondria is acidic?
The intermembrane space
128
What occurs within the nucleolus?
Ribosomal RNA production
129
What are microfilaments?
Solid polymerized rods of actin that create bundles/networks
130
What is the order of phases within the cell cycle?
G1, S, G2, and M
131
What occurs during G1?
Size of the cell increases, more organelles are produced to support energy needs
132
What is another name for G1?
The presynthetic gap
133
What occurs during S phase?
The cell replicates its genetic information
134
What is another name for S phase?
The synthetic phase
135
What occurs during G2?
The cell determines integrity of DNA, increases size and cytoplasm
136
What is another name for G2?
The postsynthetic gap
137
What occurs during M phase?
Mitosis and cytokinesis
138
What are the two checkpoints in the cell cycle?
G1/S and G2/M
139
What occurs during G1/S checkpoint?
The cell determines if the DNA has good integrity and repairs the DNA if not
140
What occurs during the G2/M checkpoint?
The cell ensures adequate size and amount of organelles to support each new cell
141
What is the main protein involved in both checkpoints of the cell cycle?
p53
142
What phases are included in interphase?
G1, S, G2
143
What is another name for G1, S, G2 in the cell cycle?
Interphase
144
When are chromosomes visible to light microscopy during the cell cycle?
During M phase
145
Why are chromosomes not visible to light microscopy during interphase?
Because they are present in uncompressed chromatids to be accessible for gene expression
146
What controls the cell cycle?
Cyclins and Cyclin-dependent kinases
147
How do cyclins and CDK's impact cell cycle?
Different cyclins are expressed at different times in the cell cycle; they bind to CDK's which phosphorylate/activate transcription factors which in turn activate genes required for changing phases
148
What are two ways that cancer can occur from cell cycle derrangement?
Oncogenes can mutate and be activated, or tumor suppressor genes can mutate and be deactivated
149
What is an oncogene?
A gene that when over-expressed promotes cell growth and division
150
What is an example of a tumor suppressor gene and its protein?
TP53 and p53
151
Where does mitosis occur?
Somatic cells
152
Where does meiosis occur?
Germ cells
153
What acronym can you use to remember the stages of mitosis?
(P)ass (M)e (A) (T)aco
154
What is the order of mitosis?
Prophase, metaphase, anaphase, telephase
155
What occurs during cytokinesis?
One cell divides into two cells
156
What occurs during prophase?
Chromatin condenses into chromosomes, the nuclear envelopes dissolve, and centriole pairs begin moving to the poles/forming spindle fibers
157
What occurs during metaphase?
Spindle fibers attach to chromosomes and align them at the equatorial plate
158
What occurs during anaphase?
Centromeres split and sister chromatids are pulled apart to respective poles
159
What occurs during telophase?
The spindle apparatus dissolves, the nucleus and nucleoli reform, chromatin reforms
160
What is the result of mitosis?
2 identical diploid daughter cells
161
What is the result of meiosis?
4 non-identical sex cells
162
Reductional division
Cell division which results in reduced ploidy
163
Equational division
Cell division which results in equal ploidy
164
What acronym can you use to remember the stages of meiosis?
(P)ass (M)e (A) (T)aco (M)(A)
165
True/False: The first stages of meiosis separate the sister chromatids
False, it separates homologous chromosomes first
166
What is the result of Telophase 1?
Change in ploidy from diploid to haploid
167
What does "formation of the tetrad" refer to?
It refers to the structure created when homologous chromosomes are connected during meiosis
168
What is synapsis?
The formation of the tetrad in meiosis
169
What is synapsis important for?
It increases genetic diversity as gene crossover can occur between homologous chromosomes
170
Which of Mendel's laws is exhibited during crossover?
Mendel's 2nd law: the law of independent assortment
171
What does Mendel's second law mean?
It means that genes are inherited independently of other genes
172
What is disjunction?
The separation of homologous chromosomes
173
What does Mendel's first law mean?
It means that there is random chance to which chromosomes are received from the mother and which are from the father
174
Which of Mendel's laws is exhibited during disjunction?
Mendel's first law: the law of segregation
175
Are sex linked diseases normally X-linked or Y-linked?
X linked
176
Are most x-linked diseases dominant or recessive?
Recessive
177
What is the consequence of more x-linked diseases being recessive?
Men are more likely to suffer manifestations due to necessary expression of these genes, whereas heterozygous women can dependent on their healthy X
178
SRY
Sex-determining region of Y
179
What is the SRY responsible for?
It initiates sex differentiation in males
180
What is the role of the seminiferous tubules?
To develop sperm
181
What are the two component cell types within the seminiferous tubules?
Sertoli cells and the Interstitial cells of Ludwig
182
What is the role of the Sertoli cell?
To nourish sperm
183
What is the role of the interstitial cells of Ludwig?
To secrete testosterone and other androgens
184
Why are testes contained within the scrotum?
For temperature regulation
185
What occurs in the epididmyus?
Sperm flagella gain motility and sperm hangout until ejaculation
186
What acronym can help you remember the path of sperm through the reproductive track?
SEVE(N) UP
187
What is the full path of sperm?
Seminiferous tubules, epididymus, vas deferens, ejaculatory duct, urethra, penis
188
What creates semen?
Sperm and seminal fluid
189
What do the seminal vesicles provide to sperm?
fructose and alkalinity
190
What does the prostate gland provide to sperm?
Alkalinity
191
What do the Cowper's glands provide?
Clear viscous fluid to clear the pathway
192
What organelle forms the acrosome?
The golgi appartatus
193
What is contained within the head of the sperm?
The genetic information
194
What is contained within the mid piece of the sperm?
Mitochondria
195
What is the acrosome's function?
It is used to penetrate the ovum
196
Spermatogonia
Diploid stem cells prior to any modifications
197
How do spermatogonia become primary spermatocytes?
They duplicate their DNA
198
Primary spermatocytes
Diploid sperm cells with sister chromatids present
199
How are secondary spermatocytes created?
Primary spermatocytes undergo M1 and homologous chromosomes split into separate haploid cells
200
Secondary spermatocytes
Haploid sperm cells with sister chromatids present
201
How do secondary spermatocytes become spermatozoa?
They undergo M2 to separate sister chromatids
202
Spermatozoa
Haploid sperm cells without sister chromatids present
203
When does oogenesis occur in the life cycle?
It happens during fetal development
204
What form are oocytes present in prepubescent individuals?
Primary oocytes
205
Primary oocyte
Diploid oocyte with sister chromatids present
206
When do primary oocytes turn into secondary oocytes?
Once per month after puberty
207
What is a large difference between meiosis in sperm cells versus egg cells?
Meiosis in egg cells results in an unequal division into the oocyte and a polar body
208
What are the layers which surround an oocyte?
The zona pellucida and corona radiata
209
Zona pellucida
Acellular glycoprotein layer directly surrounding oocyte
210
What is the function of the zona pellucida?
It is integral for sperm binding
211
When do egg cells undergo M2?
When sperm successfully penetrates layers using acrosomal enzymes
212
