Biology Flashcards
1
Q
Chromosome
A
stored and packaged DNA
2
Q
prokaryotes
A
organisms without any membrane-bound organelles
3
Q
eukaryotes
A
organisms with membrane-bound organelles
4
Q
Telomeres
A
regions of high G-C content at the end of each chromatid
5
Q
Karyotypes
A
images that visualize the chromosomes in an organism’s cell
6
Q
Aneuploidy
A
absence of a chromosome or the presence of an extra one
7
Q
Structural abnormalities
A
changes in one or more individual chromosomes
8
Q
Ploidy
A
the number of sets of chromosomes found in a cell.
9
Q
Sex chromosomes
A
23rd pair of chromosomes, which determines genetic sex
10
Q
Autosomes
A
1st through 22nd pairs of chromosomes, which do not determine genetic sex
11
Q
Locus
A
the position, or location, of a gene on a chromosome
12
Q
Genotype
A
an inherited genetic profile for a trait; determines a phenotype
13
Q
Phenotype
A
an expressed physical characteristic; determined by a genotype
14
Q
Law of segregation
A
states that the two allelic copies of genes in a diploid organism are equally segregated into gametes, such that the two gametes that are formed both receive one of the pairs of alleles
15
Q
Law of independent assortment
A
states that the separation of the alleles of one gene occurs separately and uniquely from the separation of alleles of another gene
16
Q
Homozygosity:
A
presence of two identical alleles at the same gene
17
Q
Heterozygosity
A
presence of two different alleles at the same gene
18
Q
Carrier
A
one who can pass on the recessive allele to their offspring but does not express the recessive phenotype themselves.
19
Q
Monohybrid cross:
A
analysis of potential combinations of parental alleles with respect to one gene
20
Q
Dihybrid cross
A
analysis of the allele types for two different genes, instead of one
21
Q
Test cross
A
crossing the organism of interest with a homozygous recessive individual to determine whether an organism is a dominant homozygote or a heterozygote
22
Q
X-linked recessive disorders
A
expressed in females that inherit two recessive X-linked alleles and males that inherit one X-linked recessive allele
23
Q
Codominance
A
occurs when two different alleles’ respective phenotypes are expressed at the same time
24
Q
Incomplete dominance
A
occurs when the presence of a dominant and a recessive allele creates a phenotype that is different from either dominant or recessive phenotypes
25
Penetrance
the proportion of individuals within a population that actually display the predicted phenotype
26
Expressivity
extent to which the related phenotypic trait is expressed in a single individual
27
Linked genes
genes that are found close together on the same chromosome and are thus more likely to be inherited together
28
Map units
unit used to quantify the distance between two genes on the same chromosome
29
Natural selection
process through which individuals with traits that favor their survival and reproduction outcompete individuals less fitted to the living environment
30
Genetic drift
random, spontaneous allele frequency change that is most prominent when a population faces no selective pressures
31
Bottleneck effect
low genetic variation that results when a relatively small pool of survivors are left to pass on a lower diversity of genes onto offspring after a catastrophe
32
Founder effect
low genetic variation that results when small populations that branch off the main population to form a new colony
33
Molecular clock theory
theoretical method of dating the evolutionary age of a species that states the higher the degree of genetic difference between two species, the longer ago they are assumed to have diverged
34
Hardy-Weinberg equilibrium:
theoretical state in which no allele frequencies change
35
cell theory
three tenets that describe properties of cells: living organisms are composed of cells, they are the most basic unit of life, and all new cells are products of pre-existing, living cells
36
Archaea
specific single cell prokaryote that lives in extreme environments
37
Bacteria
most common type of prokaryotic cell; classified based on shape (bacilli, spirilli, and cocci)
38
Anaerobes:
bacteria that do not use oxygen for metabolism; for some oxygen is toxic, while for others it is tolerable but not necessary.
39
Aerobes
bacteria that use oxygen for metabolism; some need oxygen while some are able to use oxygen when available.
40
Parasitic
relationship between bacteria and host that benefits the bacteria, but harms the host
41
Symbiotic
relationship between bacteria and host that does no harm, and helps one or both parties
42
Bacterial cell wall
protective structure around the cell membrane of bacterial cells
43
Capsule
a sticky polysaccharide layer around some bacteria that enhances survival of individual bacteria or bacterial colonies
44
Peptidoglycan
polysaccharide that is an important component of bacterial cell walls`
45
Gram-positive
type of bacterial cell wall that has thick layer of peptidoglycan outside the cell wall
46
Gram-negative
type of bacterial cell that has a thin layer of peptidoglycan in between the cell wall and the outer lipopolysaccharide membrane
47
Bacterial flagella
long filaments that spin like a propeller to help the bacteria move
48
Chemotaxis
movement of bacteria in response to chemical signals in the environment
49
Pili
long projections on surface of bacteria that help with attachment and movement, as well as formation of conjugate bridges
50
Plasmid
small circular pieces of DNA in some bacteria in addition to primary DNA; often code for advantageous abilities in bacteria
51
Binary fission
process of reproduction in bacteria; results in two identical daughter cells
52
Lag phase
before cells start growing and reproducing, they have to start the process, and little growth happens
53
Log phase
exponential growth of bacteria due to quick nature of binary fission
54
Stationary phase
peak of exponential growth, population size levels off due to absence of certain resources needed to reproduce further
55
Death phase
after resources are diminished, bacteria begin to die off because they can’t support further growth
56
Transduction
transfer of bacterial DNA through viruses
57
Transformation
absorption of genetic material directly from the environment without a specific carrier
58
Conjugation
Similar to sexual reproduction in bacteria; transfer of plasmid through a conjugate bridge between F+ and F- bacteria
59
transposons
“jumping genes,” DNA segments that move around in the genome providing genetic variation
60
Nucleus
houses genetic information and is involved in partial formation of ribosomes
61
Mitochondria
production of energy in the form of ATP through Krebs cycle and electron transport chain
62
Rough endoplasmic reticulum (RER)
studded with ribosomes and thus the site of protein synthesis, begins post-translational modification of some proteins, sends them to Golgi apparatus
63
Smooth endoplasmic reticulum (SER)
synthesis of lipids, mostly phospholipids; specialized functions in various organs in the body
64
Ribosomes
site of protein synthesis; 80S in eukaryotes, 70S in prokaryotes
65
Golgi apparatus
further post-translational modifications of proteins; packages proteins into vesicles to distribute to various regions of the cell
66
Lysosomes
garbage disposal of the cell; breaks down unwanted molecules into safer molecules easy to dispose of
67
Peroxisomes
metabolization of long chain lipids into medium chain lipids to go to mitochondria for further metabolization
68
Microfilaments
two strings of actin polymers for cell movement and cleavage of the cell during mitosis
69
Microtubules
polymers of tubulin dimers for cell structure and flagella/cilia composition
70
Intermediate filaments
polymers of filament monomer for structural support and cellular adhesion; keratin is a prominent example
71
Eukaryotic flagella
tail-like structure extending from eukaryotes to help the cell move; made of microtubules in 9+2 structure
72
Cilia
multiple small projections on the outside of eukaryotic cells that help move substances along the surface of the cell; made of microtubules in 9+2 structure
73
Capsid
a protein coat around all viruses that is used to classify viruses
74
Bacteriophage
a virus that is attached specifically to a bacterial cell
75
Lytic cycle:
replicating genome of virus constantly to make new virus cells until bacterium bursts and releases new viruses
76
Lysogenic cycle
virus genome incorporating into bacterial DNA and beginning the lytic cycle only when environmental triggers are observed
77
Prophage/provirus:
bacteria with viral genetic material in the lysogenic cycle
78
Retrovirus
a specific virus that uses incorporates genome into host DNA and becomes very difficult to get rid oF
79
Prion
a misfolded protein that acts as a template to misfold other proteins; cause of some fatal diseases
80
Viroid
single strand RNA capable of silencing gene expression
81
Corpus callosum
a nerve tract that forms a bridge between the left and right hemispheres of the brain
82
Parasympathetic nervous system
responsible for the “rest and digest” response
83
Sympathetic nervous system:
responsible for the “fight-or-flight” response
84
Dendrites
branch off from the neuronal cell body to receive signals
85
Axons
long extensions of the neuron that send signals to other cells
86
Neuroglia
a diverse and important group of cells that support neurons
87
Sodium-potassium pump
hydrolyzes 1 ATP to pump 3 sodium ions out of the cell and 2 potassium ions into the cell
88
Absolute refractory period
period during which no stimuli can trigger another action potential
89
Relative refractory period
period during which an action potential can occur only if the excitatory stimulus is greater than usual
90
Synapse
meeting of two neurons that generally occurs between the end of a presynaptic axon and postsynaptic dendrite
91
Neurotransmitters
small-molecule chemical messengers that pass between neurons at a synapse
92
Reuptake
process of neurotransmitter removal in which a neurotransmitter is shuttled into the presynaptic neuron through a transporter on its membrane
93
Afferent neurons
sensory neurons
94
Efferent neurons
motor neurons
95
Polysynaptic reflex arc
reflex arc that involves at least one interneuron linking afferent and efferent neurons
96
Monosynaptic reflex arcs
reflex arcs with only one synapse between an afferent and efferent neuron
97
Upper motor neuron
efferent neurons that synapse from the brain into the spinal cord
98
Lower motor neuron
efferent neurons that synapse from the spinal cord onto the neuromuscular junction
99
Skeletal muscle
tissue responsible for voluntary movement; consciously controlled and innervated by the somatic nervous system innervations
100
Sarcomere
a unit of skeletal muscle, composed of actin and myosin
101
Sarcoplasmic reticulum
a specialized membranous organelle in the sarcomere that contains high concentrations of Ca²⁺ ions
102
Smooth muscle
involuntary muscle; controlled and innervated by the autonomic nervous system
103
Cardiac muscle
muscle found in the heart; contains intercalated discs and may be multinucleated
104
Myogenic activity
electrical activity independent of the brain that regulates the rhythm of the heart
105
Actin-myosin crossbridge cycle
a 4-step cycle of ATP cleavage and actin-myosin binding that ultimately results in muscle contraction
106
Neuromuscular junction
where the nervous system’s motor neurons interact with muscles through a chemical synapse
107
Red bone marrow
typically found in spongy bone, and is the site of hematopoiesis, or red blood cell development
108
Yellow bone marrow
typically found in the cavity of the diaphysis, and stores adipose (i.e., fat)
109
Haversian canals
longitudinal canals through the center of osteons; contain blood vessels
110
Osteoclasts
bone cells that resorb bone matrix and release minerals back into the blood; stimulated by parathyroid hormone
111
Osteoblasts
bone cells that reform and grow bones; stimulated by calcitonin
112
tendons
connect muscles to bones; formed by collagen
113
Ligaments
connect bone to bone; formed by collagen
114
Pharynx
tube at the back of the mouth where air passes through; also carries food
115
Larynx
air tube that contains vocal cords; covered by epiglottis and separates air from food
116
Trachea
receives air after larynx; commonly referred to as windpipe
117
Bronchi
carry air from the trachea into the lungs, progressively branching into smaller tubes
118
Alveoli
microscopic sacs covered with capillaries that are the site of gas exchange between lungs and blood
119
Surfactant
a soapy substance that coats alveoli to prevent them from collapsing on themselves
120
Lungs
main organ of the respiratory system; site of gas exchange
121
Vasodilation
the opening of blood vessels, particularly capillaries, for different purposes
122
Vasoconstriction
the opposite of vasodilation, the closing of blood vessels
123
Goblet cells
cells that secrete mucus to help the respiratory system filter out particles and antigens
124
Epithelial cells
type of cell in the respiratory tract that contains cilia that help sweep the mucus to the pharynx
125
Diaphragm
primary muscle below the diaphragm that contracts and relaxes to control the flow of air in and out of the lungs
126
Intercostal muscles
muscles in between the ribs that aid the diaphragm during inhalation
127
Tidal volume
the volume of air contained in a normal breath
128
Expiratory reserve volume
the total amount of air that can be exhaled after a passive exhalation
129
Inspiratory reserve volume
the amount of air that can be inhaled after a passive inhalation
130
Total lung capacity
the total amount of air that can be contained in the lungs after a full inhalation
131
Residual volume
the total amount of air that remains in the lungs after a forceful exhalation
132
Vital capacity
the total amount of air that can be forced out after a full inhalation
133
Partial pressure
the pressure a specific gas within a mixture of gases exerts; commonly used for pressure of certain gases in air
134
Acidosis
a condition in the blood where the pH is more acidic, caused by excess carbon dioxide in the blood
135
Alkalosisa
condition where the blood pH is more basic, caused by a deficiency of carbon dioxide in the blood
136
Heart:
the driving force for blood in the body
137
Arteries
carry blood away from the heart
138
Veins
carry blood back towards the heart
139
Capillaries
blood vessels with very small radii that is the site for nutrient and gas exchange between blood and tissues
140
Atria
the chambers in the heart that are responsible for receiving blood from veins and pushing it to the ventricles
141
Ventricles
the chambers in the heart responsible for pumping the blood to the arteries and the rest of the body
