DAT BIO exam #1

Which of the following will occur when a red blood cell is placed in a dish of pure water that has been distilled of all solutes?

A. Plasmolysis

B. Burst

C. Shrivel

D. Formation of an endospore

E. Remain the same

Burst

When a red blood cell is placed in pure distilled water (a hypotonic solution), water will move into the cell due to osmosis. This osmotic movement causes the cell to swell and eventually burst (lyse). The correct answer is "Burst".

A significant spike in which hormone causes ovulation?

A.  FSH

B. LH

C. Estrogen

D. Progesterone

E. hCG

LH

Adaptive radiation is best described as __________.

A. The emergence of multiple lineages from a single ancestral species

B. Two closely related species mate, resulting in a hybrid

C. Two unrelated species evolve to share more similar characteristics to each other

D. The passing of traits to offspring that were acquired during one’s lifetime

E. The emergence of an adapted species over one generation

The emergence of multiple lineages from a single ancestral species

The majority of energy in an ecosystem is lost due to __________.

heat loss

Adipose tissue would be classified as which of the following tissue types?

connective tissue

Which of the following is true regarding enzymes?

A. Do not change the rate at which equilibrium is achieved

B. Increase the activation energy

C. Affect the overall energy change of the reaction (ΔG)

D. Ensure that the final state of the reaction is the same as the initial state

E. Do not change the equilibrium point of a reaction

do not change the equilibrium point of a reaction

enzyme does NOT change the free energy (ΔG) of a reaction! Although it does NOT change the equilibrium state or the enthalpy of formation (ΔH), it does INCREASE the rate constant of the forward and reverse reactions

The blood vessels in the body that carry the largest pressure are __________.

Arteries

Aorta → Arteries → Arterioles → Tissue Capillaries → Venules → veins → Superior and Inferior Vena Cava.

Veins have the lowest blood pressure and thus, require valves to prevent the backward flow of blood.

Moths in a forest can have a range of colors from pure white to pure black and any shade in between. Most moths in the forest are an intermediate shade of gray, but one year after a logging company begins to destroy the forest, most moths are either very light or very dark. Which form of natural selection took place?

disruptive selection

The cortical reaction directly functions by ___________.

Formation of an impenetrable fertilization membrane

The cortical reaction functions by forming an impenetrable fertilization membrane. This reaction prevents polyspermy (the entrance of multiple sperm into an egg), ensuring only one sperm can fertilize the egg. When a sperm penetrates the egg's plasma membrane, calcium ions cause the release of cortical granules. These granules modify the zona pellucida, making it impermeable to other sperm.

The coupling of proton transfer across a membrane with the transfer of electrons from electron donors to electron acceptors using redox reactions occurs in ___________.

Electron transport chain

All of the following are components of blood EXCEPT one. Which one is the EXCEPTION?

A. Plasma

B. Podocytes

C. Buffy coat

D. Granulocytes

E. Red blood cells

B. Podocytes

actually found in the in the Boeman's capsule of the kidneys

the buffy coat contains WBCs and includes granulocytes (neutrphils, eosinophils, basophils) and agranulocytes (monocytes and lymphocytes)

Which of the following is an example of a vestigial structure?

appendix

Which of the following anatomic structures is the lower border of the thoracic cavity?

diaphragm

Photosynthesis is a process that is required for the sustainability of all life on earth. What are the products of the light-dependent reactions of photosynthesis?

NADH, ATP, and O2

During these reactions, sunlight is absorbed by photosystem II, leading to the photolysis of water into protons, electrons, and oxygen. The electrons move through an electron transport chain to photosystem I, creating an electrochemical gradient used to synthesize ATP. These electrons then excite photosystem I, and ultimately combine with NADP⁺ and H⁺ to form NADPH.

A marine biologist discovers an organism in the ocean with the following characteristics: bilateral symmetry, body segmentation, and multiple pairs of jointed appendages. Which of the following animal phyla would this organism best be categorized as?

Arthropoda

CRUSTACEAN

What is the correct order of stages in pre-embryonic development?

Zygote, cleavage, morula, blastocyst, implantation

Autosomal recessive pedigree

an affected indvidiual may have 2 normal parents (if both parents are heterzygous)

-if 2 parents show a trait, all children must also show the trait (homo recessive)

Which of the following DNA sequences has the highest melting point when bonded to its complementary strand?

A. ACGATTATAA (2)

B. TGCGCACTAT (5)

C. AGATGCTAAG (4)

D. TGCAGGCTAC

E. ACAATGTTAG (3)

D. TGCAGGCTAC

find the one wit the most cytosine and guanine (has 6)

DNA fragments produced by restriction enzymes can be separated from one another using __________.

Gel electrophoresis

Which structure's primary function is the movement of water throughout plants?

xylem

phoelem actually transports suhar from leaves to roots

The extinction of a certain species can disturb an ecosystem and lead to other organisms being harmed. Which of the following organisms would have the most significant impact on an ecosystem upon removal?

keystone species

a species with a major ecological role that if removed, would cause a drastic alteration of the ecosystem

Where in the cell does beta-oxidation occur?

Mitochondria

Osteoporosis is a disease that causes excessive bone resorption in individuals suffering from it. This excessive bone resorption can lead to __________.

Increased circulating calcium levels

If an organism's DNA contains 30% Thymine, what percentage of guanine would be present in its DNA?

20%

(A+T) + (G+C)

A newborn duck first sees a cat after it is born and follows it, recognizing it as its mother. What animal behavior is the newborn duck exhibiting?

Imprinting

If an individual can no longer chemically modify their waste and synthesize bile, they may have a defect in which of the following organs?

Liver

In a population of mice, the coat color varies between dark fur (dominant) and light fur (recessive). The frequency of the homozygous recessive genotype is 16%. Assuming the population is in Hardy-Weinberg equilibrium, which of the following would be the allele frequency of the dominant (dark fur) allele in the mice population?

p=0.6

√0.16=0.4

p+q=1

p+0.4=1

p=0.6

A student wishes to conduct an experiment where he leaves two identical plates of yeast growing in a sugar solution. He seals one of the plates and incubates both plates overnight. Which of the following substances would be found in the sealed plate but not in the open plate?

ethanol

During the process of gastrulation, which structure is formed even in the most primitive organisms?

gut tube

Which of the following binds to an enzyme location that is NOT the active site to decrease enzyme activity?

non-ccompetitive inhibitor

Organisms can only convert energy from one form into another according to the first law of thermodynamics. Which of the following would be the ultimate source of energy for nearly all living organisms?

Light energy from the sun

A breeder attempts to cross an alpaca with a llama for thicker wool and finds that the hybrid offspring can rarely live for more than a few days. Which of the following best describes what this outcome probably resulted from?

Postzygotic reproductive isolation

refers to reproductive isolation that has occurred AFTER the fertilization of an egg

A scientist discovers a new species capable of surviving in dry environments with low water supply. This species produces highly concentrated urine. Which of the following structures would the organism possess that may explain this?

Longer Loops of Henle

These longer loops create a higher osmolarity gradient, allowing more water to be reabsorbed from the filtrate back into the body, ultimately leading to more concentrated urine. Reducing water loss is crucial for survival in arid conditions.

Which of the following statements best describes the process of gametogenesis?

Primary oocytes undergo prophase I of meiosis in the ovary and complete meiosis I in adults after puberty

Which of the following processes are topoisomerases involved in?

transcription

Which of the following direct (non-tropic) hormones has a function that increases the rate of metabolism?

Thyroxine (T4)

Which of the following uses "peristaltic action" muscle movement?

small intestine

What is the deepest layer of the epidermis that attaches to the basement membrane?

Stratum Basale

Which microbial process is responsible for the conversion of atmospheric nitrogen (N2) into ammonia (NH3) and ammonium (NH4)?

nitrogen fixation

Which of the following is common between the formation of both glycosidic bonds and phosphodiester linkages?

Formation of a water molecule

Which of the following is true of compounds secreted from the adrenal cortex?

A. They are transcribed and translated to be produced

B. They bind to intracellular receptors and alter eukaryotic transcriptional regulation

C. They are synthesized via use of a reverse transcriptase

D. They are found in prokaryotes but not eukaryotes

E. They rely on secondary messenger signaling cascades

They bind to intracellular receptors and alter eukaryotic transcriptional regulation

The adrenal cortex produces only steroid hormones and does so when stimulated by adrenocorticotropic hormone (ACTH). Steroid hormones are derived from cholesterol and exert their effects by binding to intracellular receptors. The hormone-receptor complex then binds to specific DNA sequences and regulates the transcription of target genes, either activating or repressing them

A protein is identified in a cell. Its function is unknown, but it is found to contain a hydrophobic region. This protein is most likely a __________.

A. Digestive system enzyme

B. Lipid molecule

C. Ribosomal protein

D. Herbivore

E. Membrane-spanning protein

Membrane-spanning protein

These hydrophobic regions allow the protein to be embedded within the lipid bilayer of the cell membrane, which itself has hydrophobic characteristics. Unlike other proteins that function in aqueous environments, a membrane-spanning protein requires a hydrophobic region to interact with the hydrophobic core of the membrane.

What is the relationship between vasodilation and blood pressure?

A. Vasodilation causes blood pressure to increase

B. Vasodilation has no effect on blood pressure

C. Vasodilation affects blood in lymphatic vessels only

D. Vasodilation causes blood pressure to decrease

Vasodilation causes blood pressure to decrease

The relationship between vasodilation and blood pressure is inverse. Vasodilation, which is the widening of blood vessels, causes a decrease in blood pressure. This occurs because the increased vessel diameter provides more space for blood flow, reducing resistance against the vessel walls, thereby lowering blood pressure.

Where is the location of the electron transport chain?

A. Mitochondrial matrix

B. Outer mitochondrial membrane

C. Inner mitochondrial membrane

D. Sarcoplasm

E. Archenteron

Inner mitochondrial membrane

Which of the following is the most abundant type of immune cell?

A. Macrophages

B. Basophils

C. Eosinophils

D. Neutrophils

E. Lymphocytes

Neutrophils

Never Let Monkey Eat Bananas. From most to least abundant:

Neutrophils - 60%

Lymphocytes - 30%

Monocytes - 6%

Eosinophils - 3%

Basophils - 1%

They are a type of white blood cell (leukocyte) that plays a crucial role in the innate immune response, which is the body's first line of defense against infection. Neutrophils are phagocytes, meaning they engulf and destroy bacteria, viruses, and other foreign invaders. They are also involved in the inflammatory response, which helps to isolate and eliminate infection. Their abundance allows them to rapidly mobilize to sites of infection or injury, where they perform several critical function

All of the following evolutionary advantages have led to a diverse population of insects EXCEPT for one. Which one is the EXCEPTION?

A. Metamorphosis

B. Small size

C. High reproductive rate

D. Open circulatory system

E. Multiple reproductive strategies

Open circulatory system

An open circulatory system is relatively simple and lacks the specialization of a closed circulatory system, which can transport blood more efficiently. In an open circulatory system, the circulating fluid, called hemolymph, is not confined to vessels. Instead, it is pumped by a heart into a body cavity called a hemocoel, where it directly bathes the organs and tissues.

Pregnant women often experience calcium deficiency. Which part of the body would you expect to be the most deficient?

A. Nails

B. Bones

C. Hair

D. Cartilage

E. Stomach

Bones

Most CO₂ is dissolved in the blood in what form?

A. Bicarbonate

B. Oxygen

C. Carbonic acid

D. Attached to hemoglobin in RBCs

E. Bound to iron atoms

Bicarbonate

When cells in our body metabolize nutrients for energy production (via cellular respiration), CO₂ is produced as a waste product. This CO₂ needs to be efficiently removed from tissues and transported to the lungs, where it can be exhaled. However, the solubility of CO₂ in blood is relatively low, and if it were to accumulate as dissolved CO₂, it would quickly lead to a dangerous drop in blood pH (acidosis).

The body’s solution to this challenge is the bicarbonate buffer system. The bicarbonate buffer system is incredibly efficient. It allows for the transport of significantly more CO₂ than would be possible by simple dissolution in plasma. By converting CO₂ into bicarbonate, the body effectively "hides" the CO₂, preventing it from causing acidosis. Furthermore, the bicarbonate system is reversible, allowing for CO₂ uptake in tissues and release in the lungs. The ability of bicarbonate to act as a buffer also plays a vital role in maintaining acid-base homeostasis.

When does protein degradation occur in the timeframe of protein synthesis?

A. Before transcription

B. During transcription

C. Before translation

D. During translation

E. After translation

After translation

Protein degradation typically occurs after translation because degradation processes, like the ubiquitin-proteasome system, regulate protein levels by breaking down proteins that are damaged, misfolded, or no longer needed. While some minor degradation can occur during synthesis due to quality control, the majority happens post-translation to ensure effective cellular function and protein quality control.

What is the difference between male and female gametogenesis?

A. Oogenesis creates four small gametes and spermatogenesis creates one large gamete

B. Oogenesis creates four small gametes and spermatogenesis creates four small gametes

C. Oogenesis creates one large gamete and spermatogenesis creates four smaller gametes

D. Oogenesis creates one large gamete and spermatogenesis creates one large gamete

E. Oogenesis creates four gametes that later fuse together while spermatogenesis creates only one large gamete and three polar bodies

 Oogenesis creates one large gamete and spermatogenesis creates four smaller gametes

This divergence is due to the asymmetric division in oogenesis, ensuring the ovum gets most of the cytoplasm and nutrients, while spermatogenesis results in equal-sized gametes optimized for motility and fertilization.

Which type of axon propagates an action potential the fastest?

A. Thin and myelinated

B. Thin and unmyelinated

C. Thick and myelinated

D. Thick and unmyelinated

E. All axons conduct action potentials at the same speed

Thick and myelinated

myelination allows for saltatory conduction, where the action potential "jumps" between nodes of Ranvier, increasing speed. Additionally, thicker axons have less electrical resistance, further enhancing conduction velocity. In contrast, thin axons, even if myelinated, still present higher resistance compared to thicker ones. Therefore, thick and myelinated axons conduct signals most efficiently.