3209 questions found
A control group receives no treatment and no fake procedure, so the effect being studied is simply withheld. Which control is this?
Answer: Negative Control
A p-value is 0.02 when the cutoff for significance is 0.05. How should the result be interpreted?
Answer: Statistically significant
A treatment increases Protein A from 0.1 M to 0.5 M and Protein B from 0.001 M to 0.2 M. Which protein had the greater potentiation factor?
Answer: Protein B
A control group receives a sugar pill to control for psychological effects of a painkiller study. Which control is this?
Answer: Placebo Control
A variable changes the strength or direction of the relationship between the independent and dependent variables. Which variable type is this?
Answer: Moderating variable
A study concludes that a cancer drug does not work, but in reality the drug truly does treat the cancer. Which error occurred?
Answer: Type II error
A cell displays internal viral or cancerous proteins to CD8 positive cytotoxic T cells. Which MHC class does this?
Answer: MHC Class I
An antigen-presenting cell displays an external bacterial, fungal, or parasitic antigen to CD4 positive helper T cells. Which MHC class does this?
Answer: MHC Class II
The part of an antibody that binds the antigen varies between antibodies. Which region is this?
Answer: Variable Region
A membrane protein uses calcium to bind to the same type of protein on another cell, creating tight cell-to-cell junctions. Which adhesion protein is this?
Answer: Cadherin
The part of the antibody variable region specifically binds the epitope on the pathogen. Which term describes this antibody part?
Answer: Paratope
A cellular protein binds carbohydrates on other cells, commonly for cell communication in immune contexts. Which adhesion protein is this?
Answer: Selectin
A hormone from adipose tissue signals fullness when fat stores are growing or food is in the gut. Which hormone is this?
Answer: Leptin
A kidney hormone starts the RAAS pathway to eventually raise blood pressure through aldosterone. Which hormone is this?
Answer: Renin
A hormone supports T cell development and differentiation and is more important in development than adulthood. Which hormone is this?
Answer: Thymosin
A kidney hormone increases red blood cell synthesis in bone marrow in response to low oxygen. Which hormone is this?
Answer: Erythropoietin
A kidney hormone is the active form of Vitamin D and helps PTH raise blood calcium. Which hormone is this?
Answer: Calcitriol
A hormone is released by the heart in response to atrial stretch from high blood pressure. Which hormone is this?
Answer: ANP
A hormone is mainly produced by the stomach and signals that the body needs to eat more. Which hormone is this?
Answer: Ghrelin
A hormone is produced by delta islet cells and inhibits many processes, acting like a global pause button. Which hormone is this?
Answer: Somatostatin
A hormone stimulates bile release from the gallbladder and helps stimulate digestive enzyme release. Which hormone is this?
Answer: CCK
A hormone is released by alpha islet cells and promotes gluconeogenesis, glycogenolysis, and fatty acid oxidation. Which hormone is this?
Answer: Glucagon
A hormone slows digestive motility and causes bicarbonate release to reduce acidity in the duodenum. Which hormone is this?
Answer: Secretin
A hormone is secreted by G cells and stimulates parietal cells to release HCl. Which hormone is this?
Answer: Gastrin
A fetal shunt connects the pulmonary artery to the aorta. Which shunt is this?
Answer: Ductus arteriosus
A fetal shunt connects the umbilical vein with the inferior vena cava. Which shunt is this?
Answer: Ductus venosus
A molecule is released into a duct or open area to travel to a distant place, but not through blood. Which secretion type is this?
Answer: Exocrine
A signal is released to a cell directly next to the releasing cell. Which type of communication is this?
Answer: Juxtacrine
A signal is released to nearby cells in the same general area, but not into the bloodstream. Which type is this?
Answer: Paracrine
A fetal hemoglobin curve is left-shifted compared with maternal hemoglobin. What does this mean?
Answer: Fetal hemoglobin has higher oxygen affinity
During PCR, primers bind to target sequences after cooling. Which step is this?
Answer: Annealing
A restriction enzyme is most likely to recognize which type of DNA sequence?
Answer: Palindromic sequence
During PCR, heat splits hydrogen bonds between DNA strands. Which step is this?
Answer: Denaturation
A technique amplifies DNA using denaturation, annealing, and extension. Which technique is being described?
Answer: PCR
A researcher wants to measure the exact concentration of a gene using fluorescence during PCR. Which technique is best?
Answer: qPCR
A sequence is 5’-GAATTC-3’, and its complement reads the same in the 5’ to 3’ direction after being flipped. Which term describes this?
Answer: Palindrome
A protein provides waterproofing in epidermal tissue. Which structural protein is this?
Answer: Keratin
A binding protein in blood carries four oxygen molecules and shows cooperativity. Which protein is this?
Answer: Hemoglobin
A motor protein carries cellular components away from the nucleus in the positive or anterograde direction. Which protein is this?
Answer: Kinesin
A protein in blood binds nonpolar molecules such as fatty acids, steroid hormones, bilirubin, and some drugs. Which protein is this?
Answer: Albumin
A cytoskeleton protein forms microtubules and serves as a highway for cellular transport. Which protein is this?
Answer: Tubulin
A muscle oxygen storage protein binds only one oxygen and is not cooperative. Which protein is this?
Answer: Myoglobin
A sperm region has many mitochondria and generates ATP from fructose in semen. Which region is this?
Answer: Midpiece
The sperm uses a modified Golgi body to penetrate the ovum. Which structure is this?
Answer: Acrosome
A GPCR target protein produces cAMP after being activated. Which enzyme commonly makes cAMP in this pathway?
Answer: Adenylate cyclase
A protein on the surface of sperm binds zona pellucida receptors of the ova. Which protein is this?
Answer: Bindin
A ligand binds a GPCR, causing G alpha to exchange GDP for GTP. What happens next?
Answer: G alpha-GTP dissociates from beta and gamma
A receptor dimer has an exterior ligand binding domain and interior enzymatic domains that phosphorylate tyrosines. Which receptor is this?
Answer: RTK
A hormone stimulates uterine contractions during childbirth and milk letdown, but not milk production. Which hormone is this?
Answer: Oxytocin
A hormone from the adrenal cortex increases salt reabsorption in the distal convoluted tubule, raising blood pressure and volume without changing osmolarity. Which hormone is this?
Answer: Aldosterone
A hormone from sustentacular cells inhibits FSH and LH. Which hormone is this?
Answer: Inhibin
A hormone causes mammary glands to produce milk. Which hormone is this?
Answer: Prolactin
Dopamine from the hypothalamus prevents milk production by inhibiting which hormone?
Answer: Prolactin
A hormone from the adrenal cortex raises glucose levels by stimulating gluconeogenesis and decreasing protein synthesis. Which hormone is this?
Answer: Cortisol
A female somatic cell randomly inactivates one X chromosome. What is the inactive X chromosome called?
Answer: Barr body
A pregnancy implants in the fallopian tube instead of the uterus, potentially because cilia failed to move the fertilized egg properly. Which condition is this?
Answer: Ectopic pregnancy
If fertilization does not occur, the corpus luteum is no longer needed and becomes which structure?
Answer: Corpus albicans
A hormone maintains the corpus luteum after fertilization so estrogen and progesterone do not drop early in pregnancy. Which hormone is this?
Answer: hCG
Two separate eggs are fertilized by two separate sperm, producing siblings with similar but non-identical genomes. Which type of twins are these?
Answer: Fraternal twins
One zygote splits into two embryos with identical genomes. Which type of twins are produced?
Answer: Identical twins
A population selects against both extreme phenotypes, making the intermediate heterozygotes more common. Which selection type is this?
Answer: Stabilizing selection
One extreme phenotype is selected against, making the other extreme more common. Which selection type is this?
Answer: Directional selection
Recently diverged species adapt similar traits over time due to similar environmental pressures. Which pattern is this?
Answer: Parallel evolution
Recently diverged species become more different over time. Which evolutionary pattern is this?
Answer: Divergent evolution
Distantly related species adapt similar traits over time because they live in similar environments. Which evolutionary pattern is this?
Answer: Convergent evolution
Intermediate heterozygotes are selected against, favoring both extremes. Which selection type is this?
Answer: Disruptive selection
In a monohybrid cross Dd x dd, what fraction of offspring display the dominant phenotype?
Answer: 1/2
In Hardy-Weinberg, 2pq represents which genotype frequency?
Answer: Heterozygous
Alleles that are closer together on a chromosome are separated less often during crossing over. Which term is lower for these alleles?
Answer: Recombination frequency
In a monohybrid cross Dd x Dd, what fraction of offspring are expected to be homozygous recessive?
Answer: 1/4
In an Aa x Aa cross where aa is lethal, what fraction of surviving offspring are expected to be Aa?
Answer: 2/3
In Hardy-Weinberg, q² represents which genotype frequency?
Answer: Homozygous recessive
Two variables change together mathematically, but one is not shown to directly cause the other. Which conclusion is supported?
Answer: Correlation
Both participants and observers do not know who received the placebo or the experimental drug. Which study design is this?
Answer: Double Blind
A study result is truly caused by the independent variable rather than confounding variables. Which validity is high?
Answer: Internal Validity
Error bars for two groups overlap. What should be concluded from the document’s rule?
Answer: The groups should be treated as the same
Only participants are unaware of whether they received the placebo or treatment, but observers know. Which design is this?
Answer: Single Blind
A study can be generalized only poorly because it tests a drug only on 25-year-old males but claims results for all humans. Which validity is low?
Answer: External Validity
SDS is added to proteins, giving them a uniformly negative charge and disrupting noncovalent quaternary interactions, but disulfide bonds remain intact. Which technique is this?
Answer: Nonreducing SDS PAGE
A blot detects whether a specific protein of known weight is present after reducing SDS PAGE. Which technique is this?
Answer: Western Blotting
A DNA gel shows a thicker band for one sample than another at the same location. What does the thicker band mean?
Answer: Higher concentration of that DNA
SDS and a reducing agent are added, causing all protein subunits to separate, including those held by disulfide bonds. Which technique is this?
Answer: Reducing SDS PAGE
PCR starts with 3 copies of DNA and runs for 4 rounds. How many copies are produced?
Answer: 48
A gel technique preserves a protein’s natural size, shape, and charge because nothing is added before running the gel. Which technique is this?
Answer: Native PAGE
A sarcomere region contains only thick filaments and gets smaller during contraction. Which region is this?
Answer: H zone
A sarcomere band spans the entire thick filament and does not change size during contraction. Which band is this?
Answer: A band
A muscle fiber is pale, has fewer mitochondria, relies mainly on anaerobic metabolism, and is best for short bursts. Which fiber type is this?
Answer: Fast/White Fiber
A muscle cell has many nuclei and behaves as one cell with many copies of the same organelle. Which term describes this?
Answer: Structural Syncytium
Many individual cardiac muscle cells work together as if they were one cell because they are connected by gap junctions. Which term describes this?
Answer: Functional Syncytium
A muscle fiber appears red because it has many mitochondria and uses oxidative phosphorylation for long-term contractions. Which fiber type is this?
Answer: Slow/Red Fiber
A neuron increases the intensity of its signal. According to the document, what must increase?
Answer: Frequency of action potentials
Voltage gated Na channels open and Na rushes into the cell, making the inside much more positive. Which phase is this?
Answer: Depolarization
A neuron reaches about -50 to -55 mV, causing voltage gated sodium channels to open and the cell to immediately depolarize. Which voltage is this?
Answer: Threshold Voltage
The membrane potential goes past resting membrane potential to become more negative than normal because K channels are slow to close. Which phase is this?
Answer: Hyperpolarization
The inside of a neuron is at about -70 mV due to K leak channels and the NaK ATPase. Which state is this?
Answer: Resting Membrane Potential
Voltage gated K channels open after the inside of the cell becomes very positive, allowing K to leave and the membrane potential to move back toward RMP. Which phase is this?
Answer: Repolarization
A cell commits to becoming nervous tissue, but the physical changes have not occurred yet. Which process is this?
Answer: Determination
A tissue can regrow an identical copy of itself after damage, like the liver. Which term describes this?
Answer: Regenerative Capacity
A cell physically changes shape and function after being committed to a lineage. Which process is this?
Answer: Differentiation
A signal acts on the same cell that released it. Which communication type is this?
Answer: Autocrine
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