Lecture Notes exam 2 Flashcards
1
Q
Sexual Reproduction
A
offspring arise from two parents and a mixture of genes are inherited from both, offsprings will have better chance of survival of effects of mutations
2
Q
Asexual Reproduction
A
produces genetically identical copies of a single parent (clones)
3
Q
Mitosis
A
somatic cells, purpose of growth, repair and replace, diploid to diploid
4
Q
Meiosis
A
division of specialized cells that form reproductive cells known as gametes. A diploid cell into 4 haploid gametes. Nuclear division, halves chromosome number
5
Q
2 Haploid Gametes fuse to produce
A
zygote
6
Q
Zygotes are
A
diploid 2n
7
Q
Gametes do not__, they ___
A
divide, produced by germ cells by meiosis
8
Q
How many chromosomes in human somatic cell and how many pairs
A
46;23
9
Q
Mitosis ___ chromosome number. Meiosis ___ chromosome number
A
maintain; reduce.
10
Q
Haploid
A
single set of chromosome (n)
11
Q
Diploid
A
double set of Chromosome (2n)
12
Q
Genes
A
regions in an oragnism’s DNA that encode information about heritable traits. Pairs on homologous chromosomes.
13
Q
Alleles
A
Different versions of the same gene.
14
Q
DNA is replicated
A
Once
15
Q
Meiosis 1
A
Diploid germ cell replicated its chromosome and form tetrad (pairs of duplicated homologous chromosomes); each duplicated homologous chromosome is separated from its partner
16
Q
Meiosis II
A
two haploid cells cells divide, sister chromatids are separated (like in mitosis)
17
Q
Stages of Meiosis I
A
Prophase: homologous chromosomes condense, pair up, and swap segments. Aka crossover stage
Metaphase: Chromosomes line up
Anaphase: Chromosomes separate
Telophase: A new nuclear envelope cause so two haploid nuclei form.
18
Q
Stages of Meiosis II
A
Prophase II: the chromosomes condenses with no dna replication
Metaphase II: chromosomes align
Anaphase II: Sister chromatids separate
Telophase II: 4 haploid cells
19
Q
Crossover
A
happens in proffer I, helps with genetic variability. mixture of both parents.
20
Q
random assortment produces
A
2^23 possible combinations of homologous chromosome
21
Q
Sporophytes
A
Diploid bodies with specialized structures that form spores (haploid cells) that give rise to gametophytes through mitosis
22
Q
Gametophytes
A
A multi-celled haploid body inside which on ore more gametes form
23
Q
fertilization
A
fusion of two haploid gametes (sperm and egg) resulting in a diploid zygote
24
Q
Genes occur in pairs of
A
homologous chromosomes
25
Gregor Mendel
Breeding garden pea plants
26
Characters
heritable features that vary among individuals
27
Traits
variants for a character
28
Genes
Discrete heritable units of information for traits
29
Alleles
Alternative forms of a gene
30
Each gene has a specific ___on a chromosome
locus
31
How many chromosomes do diploid cells have
2 pairs of homologous chromosomes
32
Genotype
Particular set of allies that an individual carries
| Bb, BB, bb
33
Homozygous
Two identical alleles of a gene is homozygous for that gene
34
Heterozygous
An individual with non-identical alleles of a gene
35
Phenotype
Observable traits such as color
36
Mutated genes are
new alleles whether or not it affects a phenotype
37
True breeding
individual that is homozygous for a particular trait; the same trait is produced over many generations. AA or aa
38
Hybrid
the heterozygote offspring of a cross between two individuals that breed true for different forms of a trait. Aa
39
Dominant and Recessive Alleles
Dominant is shown in a heterozygote phenotype and recessive is not
40
Genotypes of :
Homozygous dominant
Heterozygous
Homozygous recessive
AA; Aa; aa and they only have 2 phenotypes
41
Probability
A measure of the chance that a particular outcome will occur
42
Punnett square
a grid used to calculate the probability of genotypes and phenotypes among offspring of various crosses
43
Testcross
method of determine if an individual is heterozygous or homozygous dominant (BB x bb)
44
Monohybrid Cross
between two individuals that are heterozygous for a certain character. crossing of two true-breeding individuals resulting in heterozygote offspring and they are hybrids which are represented in the first filial generation. Then those hybrids are crossed with each other to produce the second filial generation
45
Mendel's Law of Segregation
Differing traits in organisms result from pairs of genetic factors that separate during gamete formation such that each gamete receives only one of the two factors.
46
Dihybrid
16 results of genotypes, and phenotype ratio is 9:3:3:1
47
Mendel's Law of Independent Assortment
during gamete formation, members of one pair of 'genetic factors' are distributed into gametes independently of other pair
48
Law of Segregation Modern
Different traits are the result of the separation of pairs of alleles on homologous chromosomes into discrete gametes during meiosis
49
Law of Independent Assortment Modern
Each pair of alleles is sorted into gametes independently of other pairs during meiosis; we now know that this law applies when the genes are located on different pairs of homologous chromosomes
50
Linkage group
all genes on one chromosome
| genes are passed on together
51
Linked genes
very close together; crossing over rarely occurs between them
52
Codominance
two non-identical alleles of a gene are both fully expressed in heterozygotes, so neither is dominant or recessive
53
Multiple Allele System
genes with three or more alleles in a population
| ex. blood types
54
Incomplete Dominance
one allele is not fully dominant over its partner, and the heterozygous offspring is a mix
55
Epistasis
Two or more gene products influence a trait, one gene product suppresses the effect of another (dog color)
56
Bell Curve
When continuous phenotypes are divided into categories and plotted as a bar chart.
57
genotype + environment=
phenotype
58
Are phenotypes qualitative
yes
59
Mendelian Genetics
Characters are controlled by a single gene
Alleles exhibit a complete dominance relationship
Phenotypes are qualitative
60
Pleiotropy
Single gene affecting many traits
61
Epigenetics
heritable changes NOT caused by change in DNA sequence
62
Genetic abnormalities
rare version of trait, not life-threateneing
63
Genetic disorder
does cause health problems, may be life threatening
64
Geneticists
study inheritance pattern in humans by tracking these genetic abnormalities and disorders through families
65
Pedigree
used to determine the probability that future offspring will be affected by a genetic abnormality or disorder
66
An allele is inherited in an autosomal dominant pattern if
if the trait it specifies appears in people with homozygous dominant and heterozygous genotypes
67
An allele is inherited in an autosomal recessive pattern if
if the trait it specifies appears only in people with homozygous recessive genotypes
68
Achondroplasia
Homozygous dominant individuals do not survive long enough to reproduce
69
Huntington's Disease
Symptoms often do not develop until after 30 years of age
| An affected individual may have already passed on the allele to offspring
70
Hutchinson-Gilford Progeria
Most individuals with this disease do not survive long enough to reproduce
71
Autosomal Recessive Inheritance
Skips generations, two recessive alleles, so heterozygotes do not have trait.
72
Albinism
Depending on which gene(s) are affected, absence or low levels of melanin may affect pigmentation of skin, hair, eyes
73
Autosomes and Sex Chromosomes pairs
22 pairs of autosomes(homologous) and 1 pair of sex chromosomes (non-homologs)
74
X-linked Disorders
inherit in a recessive pattern because dominant X chromosomes tend to be lethal in male embryos, only homozygous females have this disorder.
an ex. is color blindness
75
all new alleles arise by
mutation
76
duplication
DNA sequence that are repeated two or more times, duplication may be caused by unequal crossover in prophase
77
Deletion
Loss of some portion of a chromosome, usually causes serious or lethal disorders
78
Inversion
Part of the sequence of DNA becomes oriented in the reverse direction with no molecular loss
79
Translocation
If chromosome breaks, the broken part may get attached to a different chromosome, or to a different part of the same one.
80
Polyploid
they have three or more complete sets of chromosomes
81
Trisomy 21
down syndrome
82
Karyotype
arrangement of chromosome in pairs 23
83
Changes in sex chromosome number may
impair learning or motor skills or be undetected
84
Stem Cells
divide to produce more stem cells
OR
differentiate into specialized cells
85
Totipotent
embryonic stem cells develop into a individual
86
Embryonic Stem Cells (hESCs)
hold the potential to repair tissues that are normally not regenerated in the adult body
87
Cell Junctions
Connects cells, tights junctions (prevent fluid movement between cells), gap junctions(channel connects cytoplasm between cells) and adhering junctions(connect cels together)
88
Hierarchical Level
```
Atoms
Molecules
Organelles
Cells
Tissues
Organs
Organ System
Organism
```
89
Epithelial tissue
covers body surfaces and lines the internal cavities such as the gut
90
connective tissue
holds body parts together and provides structural support
91
Muscle tissue
moves the body or its parts
92
Nervous tissue
detects stimuli and relays signals
93
extracellular fluid
surrounds cells, provides them with nutrients, and collects cellular waste
94
Plasma
fluid portion of blood
95
Generation evolution genes
genes that will best help an individual survive and reproduce in their environment are preferentially passed on
96
Diffusion is only efficient through
short distances
97
Evolution modifies
existing structures
98
Epithelium (epithelial tissue)
A sheet of cells that covers the body's outer surface and lines internal ducts and cavities
99
Basement membrane
A layer of ECM (extracellular matrix) that is synthesized and secreted by the cells themselves
100
Simple squamous epithelium
lines blood vessels, the heart, and air sacs of lungs. allows substances to cross by diffusion
101
simple cuboidal epithelium
lines kidney tubules, ducts of some glands, reproductive tract. Functions in absorption and secretion, movement of materials
102
simple columnar epithelium
lines some airways, part of the gut. Functions in absorption and secretion, protection.
103
Cells that move substances across the surface of an epithelium have___
cilia
104
Glands are derived from_____. What does it do?
Epithelium. Secrete products destined for extracellular function
105
Exocrine Glands
ducts; external such as tears and internal such as enzymes to small intestine
106
Endocrine Glands
no ducts; cell products are released by interstitial fluid picked up by blood vessels for delivery to target hormones
107
Connective tissues
consist of cells and the extracellular matrix that is synthesized and secreted by these cells.
Connects body parts and provides structural and functional support.
Cartilage, bone, tissue and blood
108
Loose connective tissue
fibroblasts secrete ECM consisting of complex carbohydrates and protein fibers dispersed widely through the matrix
109
Dense Connective tissue
w/ dense collagen fibers. Ligaments (bone to bone) and tendons (muscle to bone)
110
cartilage
rubbery extracellular matrix, supports and cushions bones
111
adipose tissue
fat filled cells, stores energy, cushions and protect organs
112
Bone
rigid support, muscle attachment, protection , mineral storage, blood production
113
blood
connective tissue because its cells and platelets descend from stem cells in bone
114
ATP provides energy that fuels muscle ____
contractions
115
Skeletal muscle tissue
moves the skeleton (voluntary)
| long, started cells with many nuclei
116
Cardiac muscle tissue
```
heart muscle (involuntary)
striated cells with single nuclei
```
117
Smooth muscle tissue
In walls of hollow organs (involuntary), no striations, single nuclei
118
nervous tissue
detects changes in the internal or external environment, integrates info, and controls the activity of muscle and glands
119
Nervous tissue consist of specialized
signal cells (neurons) and cells that support them (neuroglial cells)
120
Neurons
excitable cells with long cytoplasmic extensions; they send an receive electrochemical signals
121
3 types of neurons
sensory neurons, interneurons and motor neurons which relay command from brain and spinal cord to muscle and glands
122
Neuroglia (neuroglial cells)
keep neurons in position and provide them with nutrients. They wrap around single sending cytoplasmic extensions of motor neurons and act as insulation that speeds the rate at which signals travel
123
integumentary system
protects body from pathogens, injuries; controls temp, excretes certain waste
124
Nervous system
detects external and internal stimuli; controls and coordinates the responses to stimuli. Integrates organ system.
125
Muscular system
moves body and is internal parts; maintains posture; generates heat by increases in metabolic activity
126
skeletal system
supports and protects body parts; provides muscle attachment sites; produces red blood cells; stores calcium, phosphorus
127
Circulatory system
rapidly transports many materials to and from interstitial fluid and cells; helps stabilize internal pH and temperature
128
Endocrine system
Hormonally controls body functions
129
Lymphatic system
collects and returns some tissue fluid to the bloodstream; defends the body against infection and tissue damage
130
Digestive system
Ingests food and water; mechanically, chemically breaks down food and absorbs small molecules into internal environment; eliminates food residues
131
urinary system
maintains volume and composition of internal environment; excretes excess fluid and waste
132
reproductive system
females: produce eggs
Male: Transfer sperm to female
133
integumentary system
consists of skin, connective and adipose tissue. Skin helps conserve water. Helps control internal temperature
134
Outer epidermis vs deeper dermis
outer contains keratinocytes and inner contains nerves, blood and lymph vessels, hair follicles and glands
135
epidermis
a stratified squamous epithelium with adhering junction and no extracellular matrix
136
dermis
consists primarily of dense connective tissue with elastin and collagen fibers.
ex. blood vessels, lymph vessels, sensory receptors, sweat glands, sebaceous glands and hair follicles
137
sensory receptor
a structure that detects a specific stimulus and sends sensory information to the brain
138
Negative feedback
process in which a change causes a response that reverses the change
ex. when you get hot you sweat
stimulus--sensory receptors--brain--muscle/gland--response
139
urinary system
filters water, metabolic wastes and toxins out of the blood, and reclaims water
140
kidneys
paired, excretory organs that filter blood and adjust level of solutes
141
marine body fish
hypotonic to its environment
142
freshwater fish
hypertonic to its environment
143
kidneys filter blood and form
urine
144
tight junctions
prevent fluid movement between cells
145
adhering junction
connects cells together
146
interstitial fluid
fluid in spaces between cells
147
coelom
human are bilateral and have a lined body cavity
148
Urine flows through ___ into a ____ that stores it
ureters; bladder
149
Urine flows out the body through the _____
urethra
150
nephron
browman's capsule
proximal tube
loop of henle (water out, sodium in)
distal tubule (water, sodium out)
151
blood is delivered to a cluster of _____ inside a bowman's capsule; fluid is ___ ___ of the blood vessels and filtered
capillaries (glomerulus); forced out
152
Glomerular filtration
first step in urine formation; occurs in Bowman's capsule
153
Tubular reabsorption
returns most water and solutes to the blood
154
Renal Medulla
fliters in kidneys
155
Tubular secretion
movement of un-needed substances from the blood of the peritubular capillaries into the filtrate (to excrete as urine); occurs along nephron's tubules
156
Concentrating Urine
flows down loop of Henle
157
Hypothalamus and Thirst
Hypo notifies you when you are thirsty by a hormone
158
Antidiuretic hormone (ADH)
released by the pituitary when sodium level rise.
159
Aldosterone
released by the adrenal cortex, increase salt reabsorption in collection ducts; water follows by osmosis; urine is concentrated
160
Renin
converts angiotensinogen to angiotensin I, converted to angiotensin II, which acts on the adrenal cortex to secrete aldosterone
sits on top of kidney
leads to aldosterone
161
reabsorption
returns most water and solute to blood
162
secretion
unneeded stuff released
163
Normal pH extracellular fluid
7.35-7.45
164
buffer system
minimizes pH changes by reversibly binding and releasing H+
165
Kidneys adjust blood pH by ___
H+ secretion; excess H+ leaves the body in urine. only organ that can release hydrogen ion
166
Ectotherms
body temp changes with environment, regulating by altering position, not metabolism (fish, amphibians and reptiles)
167
Endotherms
body temp maintained by metabolic heat (birds and mammals)
168
Heterotherms
can maintain or decrease core temp (some birds and mammals)
169
Change in body heat =
heat produced+heat gained -heat lost
170
Thermal radiation
heat is emitted into space surrounding an object
171
Conduction
heat is transferred by direct contact
172
convection
heat is transferred by movement of air or water by a breeze
173
evaporation
heat is lost when liquid is converted to a gas, sweat.
174
Hypothalamus functions like thermostat to______
maintain core temp via neg feedback
175
Fever
an increase in body temp regulated by hypothalamus, in response to infection
176
Torpor
a period of decreased metabolic rate and activity in response to low food availability
177
Hibernation
a period of dormancy during the cold season where animal is inactive
178
Estivation
desert lizards become dormant, spent season burrow deep in soil
179
sensory neurons
detect stimuli and signal interneurons or motor neurons
| Have an axon with one end that responds to stimuli
180
interneurons
process information from sensory neurons and send signals to motor neurons
many dendrites and one axon
181
motor neurons
control muscle and glands
| signals to motor neurons many dendrites and one axon
182
Central nervous system
brain and spinal cord
183
Peripheral nervous system
nerves from the CNS to the rest of the body and from the body to CNS
autonomic nerves and somatic nerves control different organs of the body
184
Nerve
consists of nerve fibers bundled inside a sheath of connective tissue
185
autonomic nerves
regulative body's internal state; glands, cardiac muscle...
186
Somatic nerves
monitor body's position and external conditions; they control skeletal muscle
187
Dendrites
receive info from other cells
188
Axons
send chemical signals to other cells
189
Mylein sheath
helps move neuron move faster
190
Voltage gate
postive feedback and allows more sodium to open
191
Membrane potential
negatively charged proteins and active transport of Na+ and K
192
Resting membrane potential
an unstimulated neuron. sodium is concentrated higher outside of the cell and potassium is higher inside cell
193
Action Potential
travels along axon to terminal
194
Graded potential
slight shift in the voltage difference across the neuron's membrane
195
threshold potential
when stimulus in neuron's trigger zone reaches, sodium channels open
196
Once threshold level is reached
membrane potential always rises to the same level as action potential peak (all or nothing response)
197
Outward diffusion of K+
causes membrane potential to decline to a bit below its resting value in a small area
198
Action potential is
self propagating- sodium ions diffuse to the adjoining region of the axon, triggering sodium gates one after another
199
Action can only move
one way, toward axon terminals- a brief refractory period after sodium gates close prevents the signal from moving backwards
200
Neuron's membrane potential over time:
resting level--threshold level--peak is action potential
201
Synapse
is the region where an axon terminal send chemical signal to a neuron, muscle fiver or gland cell (postsynaptic cel)
202
Neuromuscular junction
the synapse between a motor neuron and a skeletal muscle fiber
203
Chemical synapse
action potential trigger release of signaling molecules (neurotransmitters) from axon terminals
204
Release of neurotransmitters from vesicles of the presynaptic neuron requires ____
Calcium ions
205
Myelin sheath
increases the transmission speed of action potential
| wraps around neuron
206
Somatic nervous system
conducts information about the environment to the central nervous system (involuntary)
controls skeletal muscles (voluntary)
207
Autonomic nervous system
conducts signals to and from internal organs glands
208
Sympathetic neurons
active in stress or danger (fight or flight response)
209
Parasympathetic neurons
active in time of relaxation
210
Spinal cord
connects peripheral nerves with the brain
211
Central nervous system are made of
brain and spinal cord
212
Meninges
three membranes that cover CNS
213
Cerebrospinal fluid
fills central canal
214
Dorsal roots
sensory info
215
Ventral roots
motor signals
216
Reflex
automatic response to a stimulus, a movement or other action that does not require thought
217
Organizations of brain
forebrain, midbrain, hindbrain.
218
Weight of human brain
3 pounds or 1240 grams
219
Medulla Oblongata
connects the spinal cord
220
Pons
adjoins the medulla, it affects breathing and has connections to midbrain
221
Cerebellum
balance, motor skills and language
222
Brain stem
reflex behaviors
223
Cerebrum
main processing center. thought and language.
224
Corpus callosum
signals two hemispheres of cerebrum
225
Thalamus
receives sensory signals, sorts them and sends them to proper region of the cerebral cortex
226
Hypothalamus
center of homeostatic control of internal environment. Regulates thirst, appetite, sex and temp
227
Cerebral cortex
outermost gray matter, controls voluntary activity, sensory perception, abstract thought, language and speech
228
4 lobes of brain
frontal, temporal, occipital and parietal
229
Primary motor cortex
controls skeletal muscles
230
primary somatosensory cortex
front of the parietal lobe receives sensory input form the skin and joints
231
limbic system
governs emotion, memory and and gratifying behaviors.
| includes: hypothalamus, hippocampus, amygdala, and cingulate gyrus
232
emotional state influences
long term memory
233
Neuroglial cells
act as framework that holds neurons in place
234
Action Potential speed
120 m/s vs 10m/s for non myelinated nerves
235
Oligodendrocytes
make myelin sheaths
236
microglia
have immune sytem functions
237
astrocytes
stimulate formation of the blood brain barrier
238
ependymal cells
line brain cavities
239
Hormones
internal secretions carried by the blood that influence the activities of specific body organs
240
Hormone action
signal is transduce (charged into a form that affects target cell behavior
241
hypothalamus is the main center for control of
the internal environment – it connects structurally and functionally with the pituitary gland
242
pituitary gland
The posterior lobe secretes hormones made in the hypothalamus
The anterior lobe makes its own hormones
243
Antidiuretic hormone (ADH)
affects certain kidney cells
| Manufactured by hypothalamus, stored and released by posterior pituitary gland. Controls water
244
Oxytocin (OT)
triggers muscle contractions during childbirth
245
Releasing hormones
encourage secretion of hormones by target cells
246
Inhibiting hormones
reduce secretion of hormones by target cells
247
anterior pituitary produces hormones of its own:
Growth hormone (GH)Thyroid-stimulating hormone (TSH
248
Acromegaly
bones getting bigger as you age
249
The thyroid gland
located at the base of the neck, regulates metabolic rate
250
Parathryoids
regulate calcium levels
| Needed for bone
251
adrenal cortex
secretes steroid hormones and small amounts of sex hormones
252
cortisol
affects metabolism and the stress response
253
adrenal medulla
contains specialized neurons of the sympathetic division that release epinephrine and norepinephrine, which stimulate the fight-flight response
254
Ovaries produce
estrogens and progesterone
255
hypothalamus and anterior pituitary control secretion of
sex hormones by gonads
256
The hypothalamus produces gonadotropin-releasing hormone (GnRH)
which causes the anterior pituitary to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH
