Download DAT Bootcamp Biology Exams 2025: Questions and Detailed Answers and more Exams Biology in PDF only on Docsity!
DAT Bootcamp Biology
Exams 2025 Questions
with Detailed Answers
modern cell theory - Answer: All known living things are made up of one or more cells.
All living cells arise from pre-existing cells by division.
The cell is the fundamental unit of structure and function in all living organisms.
The activity of an organism depends on the total activity of independent cells.
Energy flow (metabolism and biochemistry) occurs within cells.
Cells contain DNA which is found specifically in the chromosome and RNA found in the cell nucleus and cytoplasm.
All cells are basically the same in chemical composition in organisms of similar species
All cells contain a nucleus for the storage of genetic material. (T/F) - Answer: False.
Modern cell theory does not state that all cells contain a nucleus for storage of genetic material. Prokaryotes cells do not contain a nucleus. Instead, their genetic material is stored in the cytosol.
The deregulation of apoptosis may lead to the development of various diseases. Which of these may develop from insufficient apoptosis?
A. Alzheimer's disease
B. Cancerous growth
C. Parkinson's disease
D. Turner Syndrome
E. Huntington's disease - Answer: B. Cancerous growth
Cancer is the result of uncontrolled cell proliferation. Apoptosis is programmed cell death, which functions both in normal cell development but is also a necessary part of destroying damaged and
mutated cells that multiply uncontrollably. If apoptosis were to be deregulated, uncontrolled cell growths, including cancer, would be an expected result.
Turner syndrome is an aneuploidy (specifically a monosomy) that is the result of a missing X chromosome due to nondisjunction in gamete formation during meiosis. - Answer: Alzheimer's, Parkinson's, and Huntington's disease are neurodegenerative diseases, which are characterized by excessive apoptosis.
A scientist wants to detach a peripheral membrane protein from the exterior of a cell membrane. Which is the best method to do so?
A. Change the salt concentrations.
B. Perform a light centrifuge.
C. Add a detergent.
D. Change the temperature of the solution.
E. Run a small current through the solution. - Answer: A. Change the salt concentrations.
Peripheral membrane proteins are held in place by hydrogen bonding and electrostatic interactions. To detach such a protein from a cell membrane's exterior, one would need to disrupt these forces. There are two methods that will accomplish this task: changing the salt concentration, or changing the pH (altering the H+ concentration).
A light centrifuge will precipitate cells and nuclei at most, only heavy centrifuges extract small soluble proteins. - Answer: Adding a detergent is a method used to extract integral proteins because they are more hydrophobic in nature. The hydrophobic detergent will destroy the membrane and expose the hydrophobic integral protein. Changing the temperature will denature the protein. Running a current through the cell isn't a common or viable method.
Miller-Urey Experiment - Answer: The Miller-Urey experiment used ammonia, methane, water and hydrogen sealed in a sterile arrangement of tubes and flasks with connecting loops. After 2 weeks, they observed several organic compounds, amino acids (11 out of 20) and their base starting materials. However, no complete nucleic acids were observed.
Channel proteins allow particles to cross the cell membrane during what non-energy consuming process?
A. Active Transport
Our muscles are made of long chains of cytoskeleton comprised of two filaments - actin and myosin. Of these, actin is a microfilament, while myosin is a motor protein. If actin degenerates, then our muscles would not contract.
The spindle fibers radiating from centrioles are composed primarily of - Answer: microtubules.
These microtubules shorten during anaphase, which causes chromosomes to be pulled apart into separate chromatids.
Lysosomes are - Answer: vesicles produced from the Golgi that contain digestive enzymes for breaking down nutrients, cell debris, and bacteria. involved in phagocytosis.
In plants, the central vacuole is known to carry out functions performed by the lysosome.
A chromosome is composed of - Answer: tightly condensed chromatin, which is the general packaging of DNA around proteins in eukaryotes.
Chromosomes are made of nucleic acids.
The extracellular matrix consists of - Answer: protein fibers and glycosaminoglycans.
competitive inhibition - Answer: when an inhibitor binds directly to the active site and prevents the reactant from binding.
competitive inhibition can be overcome by increasing the substrate concentration
no change in Vmax
Non-competitive inhibition - Answer: when an inhibitor binds to the enzyme at a binding site, and prevents the enzyme from catalyzing the reaction.
Vmax is lowered.
What is the name of the structure that allows bacteria to stick to a surface? - Answer: Pili (short tail)- fimbriae ; exchange of genetic material between bacteria and in cell adhesion.
Bacterial flagellum (long tail) - Answer: flagellin; provides locomotion to a bacterial cell.
Clathrin - Answer: a receptor protein on the surface of a cell.
nucleoid region - Answer: where the DNA exists in a bacterial cell as it does not have a nucleus.
Teichoic acids - Answer: found only on gram-positive bacteria and help keep the cell wall rigid.
Meiosis I: - Answer: homologous chromosomes pair at the equatorial plate and eventually migrate to opposite poles (no separation of sister chromatids).
Prohase I: - Answer: nucleus disassembles: nucleolus disappears and nuclear envelope breaks down, chromatin condenses, spindle develops. Microtubules begin attaching to kinetochores. Crossing over occurs here: this means genetic recombination occurs, and the nucleotide sequence of the chromosomes may be changed
Metaphase I: - Answer: homologous pairs are spread across metaphase plate. Microtubules attached to kinetochores of one member of each homologous pair. Microtubules from other site attach to 2nd member of pair.
Anaphase I: - Answer: homologues within tetrads uncouple and pulled to opposite sides (disjunction).
Telophase I: - Answer: nuclear membrane develops. Each pole forms a new nucleus that has half the number of chromosomes.
post-anal tail - Answer: the muscular tail that extends behind the anus
What produces mucus for filter feeders? - Answer: the endostyle. It also stores iodine therefore pre- cursor for the thyroid gland.
Chordates share four main features during their development: - Answer: Notochord
Dorsal hollow nerve cord
Pharyngeal gill slits
Muscular post-anal tail
complete digestive system - Answer: Nematoda
Annelida
Mollusca
Echinodermata
non-complete digestive system - Answer: Cnidaria & Platyhelminthes have a gastrovascular cavity
Peristalsis - Answer: muscle movement in the esophagus and intestine that is responsible for food motility
reflux - Answer: backward motion through the digestive tracts. Not a muscle movement.
sphincter - Answer: muscle that constricts to separate or close passages in the body.
lower esophageal/cardiac sphincter - b/w esophagus & stomach
pyloric sphincter- b/w stomach & small intestine
Contractions - Answer: shortening of muscle fibers
Tetanus - Answer: a continued state of muscle contraction during which the muscle does not relax. During tetanus, the frequency of action potentials is so high that tension is maintained throughout the muscle.
Passive immunity - Answer: occurs when one organism can pass along their antibodies to another organism to prevent infection.
Active immunity - Answer: refers to immunity where antibodies are generated by the individual themselves in response to a perceived immune threat.
Natural immunity - Answer: refers to when an immune response is generated by natural means (as opposed to an artificial method, such as the use of a vaccine)
Artificial immunity - Answer: vaccines
Permanent immunity (secondary response ) - Answer: having been previously infected, the body will be able to quickly recognize and mount an immune response to the same antigen (much faster than during the initial exposure which results in the primary response).
reflex - Answer: involuntary, rapid response to a stimulus.
Refraction - Answer: the refractory period, the time after an action potential during which a neuron will not respond to new stimulus
Twitch contraction - Answer: simple muscle response caused by one action potential, which produces a single contraction and then complete relaxation.
Oligodendrocytes - Answer: responsible for laying down the myelin sheath surrounding neurons in the central nervous system.
outer cell bodies are the grey matter while the inner axons form the white matter.
vein - Answer: moving towards heart
artery - Answer: moving away from heart
hormones that are derived from cholesterol - Answer: Aldosterone-steroid
Cortisol-steroid
Testosterone-steroid
Progesterone-steroid
Steroid hormones are synthesized from cholesterol in the smooth ER
Aldosterone - Answer: - released from the adrenal cortex
-acts on the distal convoluted tubule and collecting duct of the kidney to increase reabsorption of Na+ and excretion of K+. This leads to passive reabsorption of water in the nephron, which causes blood volume and blood pressure to rise.
Cortisol - Answer: - released from the adrenal cortex
-raises blood glucose levels
-It is a stress hormone
Epinephrine (aka. adrenaline) - Answer: - peptide hormone
-water soluble
-released from the adrenal medulla
-functions in "fight or flight" response
-raises blood glucose levels
-causes vasoconstriction to internal organs and the skin, but causes vasodilation to the skeletal muscles and increases the respiratory and heart rate.
Testosterone - Answer: - primarily produced by the interstitial cells of the testicles
-functions in spermatogenesis and is responsible for male secondary sex characteristics
Progesterone - Answer: - produced by the ovaries (later in pregnancy, the placenta also produces progesterone)
-functions in the menstrual cycle and the development maintenance of the endometrial wall and fetus
-Birth control pills frequently use high doses of progesterone (or progesterone and estrogen together) to cause negative feedback that suppresses LH and FSH levels, which in turn prevents ovulation from occurring.
Fish in freshwater environments: - Answer: - Are hyper-osmotic relative to their environment
-Drink very little water
-Salt enters the gills via active transport
-Produce large volume of urine
Fish in saltwater environments (i.e. marine fish): - Answer: - Are hypo-osmotic relative to their environment
-Constantly drink
-Salt leaves the gills via active transport
-Produce low volume of urine
Why does cartilage take a considerable amount of time to heal? - Answer: Cartilage lacks a direct blood supply. As a result, nutrients can only access cartilage through slow diffusion, hence why it takes a considerable amount of time to heal.
It is not as rigid as bone and can continually be formed throughout an organism's life.
Deuterostomes (humans) - Answer: anus; cleavages are radial and indeterminate; coelom develops directly from outpouching in the archenteron wall
Protostomes - Answer: mouth; cleavages are spiral and determinate; coelom develops from splitting of mesoderm tissue at the sides of the archenteron
allantois - Answer: - functions in to transport waste products to the placenta
-Later the allantois will form the umbilical cord between the embryo and the placenta
Cladogram - Answer: - determine if organisms are related based on phenotypes and/or physical appearance.
Gel electrophoresis - Answer: - separation of DNA, RNA, or proteins on the basis of size and charge (shorter molecules move further).
-used to determine genetic similarities and differences
-DNA is first cut up into pieces using a restriction enzyme
Karyotype - Answer: - digital image of the size, shape, and number of chromosomes of an organism
-can be used to check for down syndrome
PCR - Answer: - used to replicate and amplify a DNA sample in vitro.
-uses a synthetic primer, nucleotides, and a polymerase enzyme to clone DNA
1)Denaturation (>90C)
2)Addition of primers + Annealing (~55C)
3)Elongation (Taq Polymerase ~70C)
Northern blotting - Answer: used to identify the sequence of messenger RNA and to study gene expression.
Southern blotting - Answer: used on DNA
Western blotting - Answer: used on protein
SNOW DROP - Answer: S = Southern blotting - > DNA = D
N = Northern blotting -> RNA = R
O = O = O (nothing)
W = Western blotting -> protein = P
DNA fingerprinting - Answer: - process of keeping a database of each individual's DNA sequences and/or makeup for forensic or genetic reasons.
-based on aspects of their DNA unique to them such as short tandem repeats (STR's)
Genetic Variation - Answer: (1)Mutation-- creation of new alleles
(2)Crossing over-- genetic recombination
(3) Meiosis-- genetic recombination
(4) Independent Assortment-- different assortments chromosomes into gametes
Aneuploidy - Answer: general condition describing a situation where the genome has an extra or missing chromosome number, often caused by nondisjunction.
Haploid - Answer: - single sets of chromosomes
Diploid (aka. Disomic) - Answer: - two sets of chromosomes
-Humans are diploid (2n)
Tetraploid - Answer: - four sets of chromosomes (4n)
-Cells with more than two sets of homologous chromosomes (such as triploids and tetraploids) are said to exhibit polyploidy which is common in plants.
Brackish water - Answer: - mix between salt and fresh water, which would be found in an estuary
- An estuary is a specific area where freshwater meets seawater.
commensalism - Answer: +/
Allelopathy - Answer: - production of biochemicals by an organism that influences the growth, survival, and reproduction of other organisms.
-interference competition, which occurs directly between individuals via aggression; other individuals are directly prevented from physically establishing themselves on a shared habitat.
chaparral biome - Answer: - highly seasonal precipitation, with rainy winters and dry summers
-shrubs, grasses, and herbs
-deer and goats
-California coastline, and many California fires happen here.
What is the original source of energy used to drive the light independent reactions(aka Dark Reaction or Calvin-Benson Cycle) of photosynthesis? - Answer: Light, or photons. The light independent reactions takes the energy produced in the light dependent reactions along with CO2 to produce glucose.
Substrate level phosphorylation - Answer: - related to glycolysis, or breaking down glucose
-produces ATP via direct enzymatic transfer of a phosphate group to ADP without the use of any carriers
Photolysis - Answer: the splitting of water molecules which yields electrons, protons, and O
where is ATP produced? - Answer: - mitochondrial matrix of the mitochondria
-this ATP is used as energy to power cellular activities
glycolysis and the Krebs cycle produce ATP via - Answer: - substrate level phosphorylation
-glycolysis occurs in cytoplasm
the electron transport chain produces ATP via - Answer: oxidative phosphorylation
Lipases - Answer: enzymes that digest fats
Adipose tissue - Answer: - body fat
-Fats are made of triglycerides, which contain a glycerol backbone and fatty acid chains, which make up lipids.
Nucleic acids - Answer: - polymers of nucleotides which consist of a pentose sugar, phosphate group(s), and nitrogenous base.
-held together on a phosphate backbone via phosphodiester bonds
-what DNA and RNA are made of
-digestible by nucleases
Glycogen stores - Answer: - long chains of glucose molecules, which are carbohydrates
-primarily serves to store energy in animal cells
Skeletal fragments - Answer: - are bones and made of bone matrix, an organic and inorganic mixture
Actin and myosin - Answer: - make up muscles
-are made of proteins
-involved in the cleavage furrow of animal cells
-make up the thin and thick filaments of the sarcomeres used in skeletal muscle contraction
- Actin: found in cytoplasm & nucleus
-contains sulfur
cytokinesis in animal cells - Answer: cleavage furrow develops
cytokinesis in plant cells - Answer: vesicles from the Golgi bodies migrate and fuse to form a cell plate to separate the two cells
Molecular chaperones - Answer: assist in the folding of complex proteins
DNA - Answer: - found only in nucleus
-transcription and replication both occur in the nucleus
RNA - Answer: - nitrogen
-found in nucleus and cytoplasm
-translation occurs in the cytoplasm
(2) Mitochondria, chloroplasts (if present), lysosomes, peroxisomes, golgi
(3) Microsomes (vesicles of disrupted endoplasmic reticulum and pieces of plasma membrane)
(4) Ribosomes, viruses, larger macromolecules
SDS (sodium dodecyl sulfate) in protein analysis - Answer: (1) Denatures the protein
(2) Linearizes the protein
(3) Adds negative charge to the protein
- Answer: - larger molecules are broken down, releasing energy
-exergonic reaction
Anabolism - Answer: - larger molecules are built up, which requires energy
-endergonic process
-athletes take anabolic steroids to build muscle
Electrochemical gradient - Answer: (1) Flagella use proton force to spin and give locomotion to bacteria.
(2) Mitochondria use a proton force in ATP synthesis
(3) chloroplasts use it to produce NADPH
(3) Neurons use Na+/K+ ATPase to create an electrochemical gradient by pumping 3 sodium ions out of the cell and 2 potassium ions into the cell.
- Answer: protein structures in the membrane that help water passively flow into or out of the cell (facilitated diffusion)
Alteration of Generations - Answer:
Acoelomates
- lack a true coelom - Answer: Platyhelminthes
-Flatworms, trematodes, flukes, tapeworms, and planarians.
Pseudocoelomates
- have an internal cavity, but one that is not completely lined by mesoderm derived tissue - Answer: -Nematodes
-Rotifers
Coelomates
- have a cavity lined by mesoderm derived tissue - Answer: - Annelids (earthworms & leeches)
-Mollusks (clams, oysters, snails, and slugs)
-Arthropods
-Echinoderms (starfish, sea cucumbers & sea urchins)
-Chordates (tunicates, lancelets, & all vertebrates)
Bacteria Naming - Answer:
epiglottis - Answer: - prevents food from going down the trachea instead of your esophagus
-when you choke it's bc epiglottis didn't do it's job
amylase - Answer: - digestive enzymes in the mouth
-begins the breakdown of carbohydrates
-secreted in saliva by salivary glands
