Biology Flashcards
Hardy-Weinberg Equation
p + q = 1, p = frequency of S, q = frequency of s
p^2 + 2pq + q^2 = 1
p^2 = SS, 2pq = Ss, q^2 = ss
SRY Gene
mammalian sex-determining gene, found on Y chromosome (male) its expression induces development of the testes–absence of the SRY protein = female
A subset of aggressive cancers has a relatively high growth rate, leading to formation of large tumors. An effective drug against fast-growing tumors would most likely NOT target which stage of the cell cycle?
G0–cells within tumors are actively dividing, can be assumed that majority of the cells are in interphase and not arrested in G0
What do kinesin motors do?
transport mitochondria and other intracellular cargo along microtubules in anterograde axonal transport (away from nucleus)
Dynein
participates in retrograde axonal transport of intracellular cargo (towards nucleus)
Mature egg and sperm
are both haploid (1N), they each contain 22 unpaired autosomes and 1 sex chromosome, resulting in 23 chromosomes
Southern Blot
used to detect a particular sequence of DNA, can determine relative gene count
Northern Blot
detects a particular sequence of RNA, cannot determine relative gene count
Menopause
production of estrogen and progesterone within the ovaries declines substantially, leading to numerous physiological changes
Vasoconstriction
smaller blood vessel diameter, less blood flow, higher BP
Vasodilation
larger blood vessel diameter, increased blood flow, lower BP
The genetic code is said to be degenerate because there are 64 different codons, but translation produces only 20 unique AAs. The degeneracy of the genetic code is due to which mechanism?
nontraditional base pairing of the anticodon with the third base of the codon
What helps maintain the resting membrane potential of a neuron?
passive transport, adenosine triphosphate, membrane selective permeability
Bacteriophages
viruses that exclusively infect bacteria, life cycle can be lytic or lysogenic
Lytic Life Cycle
- Attachment
- Viral Genome Entry
- Host Genome Degradation
- Synthesis
- Release
Archaea
unicellular, have a circular chromosome, have no membrane-bound organelles or nucleus, and reproduce asexually via binary fission (do not have peptidoglycan cell wall)
During a parasitic infection, which of the following would most likely be responsible for phagocytosis of organisms and the release of histamine, respectively?
Macrophages, basophils
Basophils
release chemical mediators, such as histamine, enhance immune response
Mast cells
release chemical mediators, such as histamine, modulate allergic reactions
Neutrophils
kill and phagocytize bacterial cells
Eosinophils
defend against parasitic infections and modulate immune responses during allergic rxns
NK cells
release toxins to destroy virus-infected body cells
B cells
identify foreign pathogens, antigen presenting, and producing antibodies
T cells
mediate a number of immune responses, including those against viruses, bacteria and parasites
WT1 and c-Myc most likely alter TERT transcription levels by doing which of the following at the TERT gene promoter?
inhibit and facilitate RNA polymerase binding, respectively
Alternate Splicing
produces multiple protein products from the same gene, not multiple similar genes
Conjugation
exchange of genetic info between prokaryotes, typically in form of plasmid DNA
Transformation
occurs when prokaryotes pick up foreign genetic material from their surroundings
Hormones secreted by the adrenal medulla most likely influence energy metabolism by:
inhibiting proteins that mediate glycogen synthesis
Endocytosis
a type of transport in which molecules that can’t cross the plasma membrane enter through vesicles (endosomes) formed by the plasma membrane
Receptor-mediated Endocytosis
highly specific, a particular extracellular molecule binds to its corresponding receptor on the cell surface—binding triggers invagination of plasma membrane
Spleen
filters aged/damaged red blood cells (RBCs), reservoir for blood, immune response (B cell activation site, housing macrophages)
Sodium Dodecyl Sulfate (SDS)
strong anionic detergent that denatures and confers a net negative charge on the protein, eliminating its shape and charge as separation factors (SDS disrupts only noncovalent bonds)
2-mercaptoethanol
added to disrupt disulfide bridges, allowing each subunit to separate as individual polypeptides
What are the functions of liver cells?
regulate blood glucose, storage of glycogen, synthesis of macromolecules, production and secretion of bile, breakdown/detoxification of numerous drugs and metabolic waste products
What are functions of the liver?
Ketogenesis (synthesis of ketone bodies) if glycogen stores are depleted, detoxification of drugs, synthesis of plasma proteins
Compared with blood in the pulmonary veins, blood in the pulmonary arteries has higher concentrations of:
H+ and CO2 than O2
Which cellular process would most likely lead to increased genetic diversity in a population of organisms?
synapsis involving two homologous chromosomes—in prophase I of meiosis, homologous chromosomes recognize each other and line up side by side
Alternative Splicing
a single gene transcript is processed to produce various mRNA molecules that encode different proteins, depending on the inclusion or exclusion of particular exons
Fluid Mosaic Model
all components can migrate laterally through the membrane
Peroxisome
contain various oxidoreductase enzymes and function to help maintain the proper oxidation state within cells
Protons from the cytosol most likely enter the endosomal lumen by which of the following processes?
active transport; energy is required to pump protons into lumen against the concentration gradient (cytosol has low H+, high pH)
Capsid
ALL viruses contain this protective protein coat
Enveloped Viruses
have an additional phospholipid bilayer surrounding the capsid
Non-enveloped Viruses
aka naked viruses, have only a capsid, but are more resistant to heat, detergents, and changes in moisture
Prion
a misfolded protein that acts as an infectious agent by inducing other normal proteins to change their secondary structure and become misfolded; become less soluble, aggregate and can cause disease, do not contain genetic material and cannot transform bacteria
Viroids
pathogenic, circular, single-stranded RNA molecules lacking protein coats and primarily affect plants—silence expression of specific genes and inhibit protein synthesis by binding RNA sequences; they hide inside viruses or damaged tissue
The neuroendocrine signaling cascade that induces adrenal hyperplasia involves coordinated activity among:
hypothalamus, pituitary gland, adrenal glands, respectively
How is the serum level of glucose regulated?
the hormones insulin, glucagon, epinephrine, norepinephrine, and the glucocorticoids
Why is aldosterone secreted by the adrenal cortex?
in response to elevated plasma potassium and decreased blood pressure—acts on kidneys to increase reabsorption of sodium and water and ultimately blood volume and pressure
Pyrimidines
one-ringed bases (C and T)
Purines
two-ringed bases (A and G) for RNA it is (A and U)
Hormones secreted from the posterior pituitary are synthesized in the:
hypothalamus
Human cardiac muscle differs from skeletal muscle because it:
contains intercalated discs
The gustatory-salivary reflex can be modulated by input from higher centers in the CNS. To modulate the salivary response, descending pathways from the brain would most likely synapse onto which part of the reflex arc?
the preganglionic neuron—reflexes are involuntary responses to stimuli that don’t require input from brain
Somatic Nervous System
voluntary motor nerve fibers transmit impulses form CNS to skeletal muscles
During periods of stress, many individuals experience dry mouth caused by decreased salivation. Which of the following functions would also be expected to decrease during periods of stress?
digestive peristalsis
