Biology Flashcards
What are the four key ideas of the theory of cells?
- the cell is the basic functional unit of life
- cells arise only from other cells
- cells pass on genetic information (DNA)
- all living things are made of cells
What is the main difference between prokaryotic an eukaryotic cells?
Eukaryotic cells have a true nucleus enclosed by a membrane
Would prokaryotes or eukaryotes have their DNA wound around histone proteins?
Eukaryotes
Would prokaryotes or eukaryotes have DNA transcription and translation occur simultaneously?
Prokaryotes
Would prokaryotes or eukaryotes have an absence of non-coding DNA?
Prokaryotes
Would prokaryotes or eukaryotes have lysosomes and peroxisomes?
Eukaryotes
What part of the cell allows for the diffusion of substances around the inside of the cell?
The Cytosol (Cytoplasm)
What part of the nucleus allows for the selective exchange of materials?
Nuclear Pores
Where is rRNA synthesized in the cell?
Nucleolus
What are the numerous folds of the inner mitochondrial membrane called?
Cristae
How is the matrix of a mitochondria different from its intermembrane space?
The matrix is the space enclosed by the inner membrane while the intermembrane space is between the outer and inner membranes
What is the process by which mitochondria replicate there own genes and undergo binary fission?
Cytoplasmic (extranuclear) inheritance
The release of chemicals from what cell organelles can lead to apoptosis?
Mitochondria
and
Lysosomes
What organelles break down many substances inside the cell by combining with endosomes?
Lysosomes
Is the endoplasmic reticulum apart of the nuclear envelope?
Yes; it is an extension of it
How do rough and smooth ER function differently?
Rough- site of ribosome production, makes and stores proteins mainly
Smooth- no ribosomes, makes and stores lipids mainly, also used in detoxification
What cell organelle modifies and packages cellular materials?
Golgi Apparatus
What cell organelles breakdown fatty acids and help synthesize phospholipids?
Peroxisomes
What are the 3 components of the cell’s cytoskeleton?
- Microtubules
- Intermediate Filaments
- Microfilaments
What component of the cytoskeleton is responsible for the cleavage furrow formation during cytokinesis?
Microfilaments (made of actin)
What component of the cytoskeleton is responsible for the formation of cilia and flagella as well as the mitotic pulling done by centrioles during mitosis?
Microtubules
What component of the cytoskeleton is responsible for the rigidity and other random cellular works?
Intermediate Filaments
What are the four tissue types?
- Epithelial
- Connective
- Nervous
- Muscle
What is the difference between a tissues parenchyma and stroma?
Parenchyma is the functional part of the organ while the stroma is everything else
Would prokaryotes or eukaryotes have circular DNA?
Prokaryotes
What are the two domains that contain only prokaryotes?
- Bacteria
and - Archaea
What domain of prokaryotes are considered extremophiles for there ability to live in a wide variety of environments?
Archaea
Which group is more similar, Archaea and Eukaryotes or Bacteria and Eukaryotes?
Archaea and Eukaryotes
What are the 3 classifications of bacteria by shape?
- Cocci (spherical)
- Bacilli (rod)
- Spirilli (spiral)
What is the difference between obligate aerobes, obligate anaerobes, facultative anaerobes, and aerotolerant anaerobes?
Obligate Aerobes- bacteria that require oxygen for metabolism
Obligate anaerobes- cannot survive in environments with oxygen
Facultative anaerobes- can switch between using oxygen and other sources for metabolism
Aerotolerant anaerobes- cannot use oxygen for metabolism but can still survive
What is the difference between gram positive and gram negative bacteria?
Gram Positive bacteria- contain a thick cell wall with a lot of peptidoglycan for added protection
Gram Negative bacteria- contain peptidoglycan but in small amounts
What part of bacteria trigger and immune response by a human?
Components of the cell wall
Where do prokaryotic organisms carryout energy production?
They use the plasma membrane for the ETC
By what mechanism do prokaryotic cells divide?
Binary Fission
Where do bacteria carry extrachromosomal information as well as information that is beneficial to the bacteria such as antibiotic resistance?
Plasmids
What are the 3 methods that bacteria can increase genetic diversity?
- Transformation- integrating genetic material that is spilled out from nearby bacteria
- Conjugation- similar to sex for bacteria
- Transduction- is when a virus carries genetic material between bacterial cells
What are the 4 phases of bacterial growth?
- Lag phase- bacteria adapt to new environment
- exponential phase- high growth
- stationary phase- reduction of growth resources
- death phase- bacteria have used all resources
What is the protein coating that surrounds a virus?
Capsid
What are the viral progeny that a virus creates by hacking the replication process of bacteria?
Virions
In bacteriophages, what part of their composition acts like a syringe that injects genetic information into the bacteria?
Tail Sheath
In bacteriophages, what part of their composition acts like hands that hold the virus in place on the bacteria and recognize the correct bacteria?
Tail Fibers
How are retroviruses different from regular viruses in terms of their replication?
Retroviruses synthesize DNA from RNA and then this DNA is inserted into the host cells genome and replicated to create Virions
What is the difference between a bacteriophages lytic and lysogenic cycles?
Lytic- the virus creates so many virions inside the host cell that the cell lyses (burst)
Lysogenic- the virus does not burst the host cell but merely lives inside and produces virions
What subviral particles are highly dangerous to humans as they are infectious proteins that effect the function of proteins in the body?
Prions
What is the difference between Diploid (2n) and Haploid (n)?
Diploid Cells- are autosomal cells that have a two copies of each chromosome (n represents number of each chromosome. Thus diploid cells will have one chromosome 17 from dad and one from mom
Haploid Cells- are germ (sperm or egg) cells that have one copy of a chromosome. Thus haploid cells will have one chromosome 17
What are the 3 stages that occur during interphase of the cell life cycle?
- G1- growth in size and create more organelles, passage to next phase is governed by a restriction point
- S- cell replicates is genetic material (chromosomes now have 2 sister chromatids, thus there are four sets of DNA for each chromosome)
- G2- cell goes through quality control to make sure all organelles replicated correctly
How many chromatid are present for one chromosome during the G1 compared to the S phase of the cell cycle?
During G1 phase each cell chromosome will have 2 chromatid (one from each parent cell)
During S phase each cell chromosome will have 4 chromatid (2 sets of sister chromatid)
What protein plays a major role in the check point between the G1 and S phase as well as the G2 and M phase?
p53 protein
What two molecules are responsible for activating transcription factors to allow for cell growth and division?
Cyclins activate Cyclin-dependent Kinases which activate transcription factors
What are the stages of mitosis in order?
- Prophase
- Metaphase
- Anaphase
- Telophase
What happens during prophase of mitosis?
- DNA condenses into tightly bound chromosomes
- centrosomes relocate to either side of the cell and start sending out spindle fibers from the centrioles
What happens during metaphase of mitosis?
- the chromosomes (consisting of sister chromatid) are pulled into alignment in the center of the cell
What happens during anaphase of mitosis?
- the sister chromatid from each chromosome are pulled a part
What happens during telophase of mitosis?
- a nuclear membrane forms around the chromosomes
- cytokinesis breaks the two daughter cells apart
List 3 differences between mitosis and meiosis
- In meiosis, the result is 4 genetically different daughter cells due to 2 rounds of division
- In meiosis, the first metaphase is the alignment of homologous chromosomes in a tetrad
- In meiosis, the lining up of tetrads allows for recombination and genetic diversity
How many chromosomes do humans have? How many homologous pairs?
Humans have 46 chromosomes total due to having 23 pairs of the same chromosome
What is the pathway of sperm through the male reproductive system? What is the mnemonic for this?
The mnemonic is when a guy is hard he is SEVEN UP
S- seminiferous tubules (sperm creation)
E- epididymis (sperm storage and motility gain site)
V- vas deferens
E- ejaculatory duct
N- (nothing)
U- urethra
P- penis
Where do sperm gain their motility?
The Epdidymis
What are the components of semen?
- sperm
- fructose (produced in the seminal vesicle)
- alkaline properties (produced in seminal vesicles and prostate gland)
- clear viscous fluid (produced in the bulbourethral gland)
What is the difference between spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids, and spermatozoa?
Spermatogonia- sperm stem cells
Primary Spermatocytes- diploid sperm cells
Secondary Spermatocytes- haploid sperm cells
Spermatids- un-maturated spermatozoa
Spermatozoa- mature sperm cells
What are the 3 main parts of a sperm cell?
- Head- capped with an acrosome, designed to penetrate the ovum of egg cells
- Midpiece-filled with mitochondria for energy production
- Tail- powers the motion of the sperm cell
How do women store the eggs that they are born with?
They are stored in the multi-layered sacs known as follicles in the ovaries of the reproductive tract
What is the process by which one egg per month is moved from the ovaries to the uterus?
Ovulation
What is the route an egg takes for ovulation?
Travels from the ovaries into the fallopian tubes (oviduct) then the uterus
What triggers meiosis II in secondary oocytes?
The penetration of a sperm cell into the egg
What are the two layers that surround an oocyte?
- Corona Radiata (outer)
2. Zona Pellucida (inner)
How do FSH and LH effect sexual development in men?
FSH increases the production of sperm
LH increases the production of testosterone
How do FSH and LH effect sexual development in women?
FSH increases the release of estrogens
LH increases the release of progesterone
How do Estrogens and Progesterone effect the endometrium during pregnancy or ovulation?
Estrogens increase the thickness of the endometrium
Progesterone helps maintain and develop the endometrium
What are the four phases of ovulation?
- Follicular- begins when menstrual flow (from the last cycle) begins, is the thickening of the endometrium in preparation for an egg
- Ovulation- a spike in LH causes ovulation or the movement of an egg into the uterus
- Luteal Phase- progesterone starts to be secreted at high rates
- Menstruation- if no implantation occurs, progesterone levels decline and the uterine lining is sloughed off
Mnemonic- Fear Of Losing Menses
What occurs when the acrosome of a sperm cell is able to penetrate an oocyte?
The sperm and egg form an acrosomal apparatus and eventually form a fused plasma membrane. This is the start of a diploid zygote
After dividing several times, what is the zygote referred as?
A Morula
During embryonic development, what does the morula become? What is the memory phrase for this?
A Blastula
The morula has its inside blasted out
In a Blastula, what is the difference between the inner cell mass and the trophoblast?
Inner cell mass- contains cells that grow and differentiate into the organism itself
Trophoblast- contains cells that become the chorion, placenta and other fetus-protecting tissues
How are the cells nourished during embryonic development before the umbilical cord can be attached?
The Yolk Sac (eventually becomes the cord itslef)
What occurs in the embryonic development process of implantation?
The blastula attaches to the endometrium
After implantation, the blastula is able to develop three distinct cell layers in a process called what?
Gastrulation
In Humans and other deuterostomes, what does the blastopore of the gastrula develop into?
The Anus
What are the three layers present in a gastrula?
- Ectoderm
- Mesoderm
- Endoderm
From what primary germ layer of the gastrula would the cells of the hair, skin, eye lens, mouth, and nervous system come from? What is the phrase to remember this?
The Ectoderm
Remember that the ectoderm is the attract-o-derm and that we get nervous when we see someone attractive
From what primary germ layer of the gastrula would the cells of the musculoskeletal, circulatory, excretory, and gonads come from? What is the phrase to remember this?
The Mesoderm
Remember that the mesoderm is the move-o-derm that gives rise to cells that allow for movement both internally and externally
From what primary germ layer of the gastrula would the cells of the digestive tract, respiratory tract, lungs, pancreas, thyroid, and bladder?
The Endoderm
Remember that the endoderm is the endernal-o-derm and creates cells that line the internal passages
From what primary germ layer of the gastrula would the cells of the adrenal cortex and adrenal medulla come from? Why?
Adrenal Cortex- the mesoderm because it is an internal organ
Adrenal Medulla- the ectoderm because it is technically nervous tissue
What process allows cells to differentiate?
Selective Transcription
Describe what happens in the process of neurulation.
- A rod of mesodermal cells form a rod that will become the spine
- A group of ectodermal cells push together until the form two peaks known as the neural groove. These neural groove peaks grow together to form a neural tube which will become the CNS
- At the tips of the neural grooves are neural crest which eventually spread out and become the PNS
What are chemicals, compounds, or other harmful substances that interfere with embryonic development?
Teratogens
In development, what is the difference between specification and differenitiation?
Specification- the cell is reversibly designated as a specific cell type
Differentiation- the cell commits to a specific cell type
What is the difference between totipotent, pluripotent, and multipotent stem cells?
Totipotent- can turn into any cell type and are what embryonic stem cells are
Pluripotent- can turn into any cell type except for the placental structures
Multipotent- can turn into any cell type within a certain group such as blood cells
What are cells that signal other cells to differentiate called?
Inducers
How is fetal hemoglobin different from regular hemoglobin?
Fetal Hemoglobin has a way higher affinity for oxygen so that it can pick up oxygen from its mother’s hemoglobin
What are the two arteries that carry deoxygenated blood in humans?
- Pulmonary Arteries
2. Umbilical Arteries
Where does blood oxygenation occur for a fetus?
In the placenta where blood oxygen diffuses across it
A fetus would be harmed if it sent blood to the lungs or the liver. What are the names of the shunts created to prevent this?
Lungs- foramen ovale AND ductus arteriosus
Liver- ductus venosus
How long does human gestation last?
280 days
What is another word for vaginal birth?
Parturition
Where is an action potential first generated in a neuron
Axon Hillock
What cells produce myelin in the CNS? What cells in the PNS?
CNS- myelin is produced by Oligodendrocytes
PNS- myelin is produced by Schwann Cells
What are the gaps in the myelin sheathing where the action potential is regenerated along the axon?
Nodes of Ranvier
What is another name for the axon terminal?
Synaptic Bouton
What is a bundle of neurons called?
Nerve
What is the difference between a tract and a nerve?
Nerve- a bundle of neurons carrying information in either direction and are located in the PNS
Tracts- a bundle of neurons carrying information in one direction and are located in the CNS
What are the four types of glial cells in the CNS?
- Oligodendrocyte- produce myelin
- Astrocyte- create the blood-brain barrier as well as nourish the neurons with nutrient
- Ependymal Cells- produce cerebrospinal fluid
- Microglia- macrophage activity
What is the resting membrane potential in most neurons?
-70mv
What 3 channels are responsible for creating resting membrane potential and which direction do ions flow through these when the neuron is at rest?
- Na+/K ATPase pump that brings two K+ ions in and three Na+ ions out
- K+ leak channels that allow the membrane to be more permeable to K+ at rest and allow K+ to flow out of the cell
- Na+ leak channels that allow some Na+ to flow into the cell
What are the equilibrium potentials for Na+ and K+?
Na+ is around 60 mv
K+ is around -90 mv
What is the typical threshold potential for neurons?
-55 to -40 mv
What is the difference between temporal and spatial summation that reaches the axon hillock in a neuron?
Temporal- a graded potential is created by the same pre-synaptic neuron in rapid succession
Spatial- a graded potential is created by different pre-synaptic neurons at the same time
What is the difference between the relative and absolute refractory periods?
Absolute- an action potential cannot be generated
Relative- a greater than normal stimulation must occur because the membrane is hyperpolarized
Describe what type of neuron would transmit the fastest possible signal
A neuron that is:
- myelinated (allowing for saltatory conduction)
- short (preventing increased resistance)
- large radius (preventing increased resistance
What ion is essential in the release of neurotransmitters into the synaptic cleft?
Ca2+
What are the 3 main ways that neurotransmitters are removed from the synaptic cleft?
- Broken down by enzymes
- Reuptake- brought back into the presynaptic neuron by reuptake carriers
- Diffusion away from the synaptic cleft (mainly gases)
What is the difference between white and grey matter in the CNS?
Gray- Cell bodies and dendrites
White- myelinated axons
What is another name for efferent neurons?
Motor Neurons
Where do afferent (sensory) neurons enter the spinal cord?
Dorsal Roots
Where do efferent (motor) neurons exit the spinal cord?
Ventral Roots
How many neurons are used to signal an effector in the autonomic nervous system? How about the somatic?
Autonomic- uses two neurons that are separated by a ganglion
Somatic- uses one neuron (usually with a long axon)
What is the neurotransmitter used by the parasympathetic nervous system?
Acetylcholine
What is the primary neurotransmitter used by the sympathetic nervous system?
Epinephrine and Norepinephrine
What part of the autonomic nervous system is also known as the craniosacral division?
Parasympathetic
What part of the autonomic nervous system is also known as the thoracolumbar division?
Sympathetic
What division of the autonomic nervous system would cause an increase in heart rate?
Sympathetic
What division of the autonomic nervous system would cause the bronchi to relax?
Sympathetic (this would allow for more oxygen exchange)
What division of the autonomic nervous system would cause the pupils to constrict?
Parasympathetic (not as alarmed)
What division of the autonomic nervous system would cause an increase in the blood glucose levels?
Sympathetic
What is the difference between a monosynaptic and a polysynaptic reflex
Monosynaptic- there is a single synapse between sensory neuron that receives the stimulus and the motor neuron that responds to it
Polysynaptic- there is at least one interneuron between the two
Would the K+ voltage gated channels be open or closed during a depolarization? What about during a repolarization?
Depolarization- K+ channels would be closed
Repolarization- K+ channels would be opening
What are the 3 types of hormones?
- Steroid
- Amine
- Peptide/Protein
Which of the 3 types of hormones are water soluble?
Peptide/Protein hormones are water soluble
AND
Catecholamines of the amine hormones
Which of the 3 types of hormones are not water soluble?
Steroid hormones
AND
Thyroid hormones