ATI TEAS VII Online Practice A - Science

Vitamin B12 is converted to methyl-cobalamin, which is consumed in a reaction where methionine synthase produces the amino acid methionine. Which of the following molecules is the catalyst in this reaction?

Vitamin B12

Methyl-cobalamin

Methionine synthase

Methionine

Methionine synthase

Methionine synthase has the suffix -ase, which is a standard nomenclature for enzymes. Its name further indicates that it helps to make methionine, so it is a catalyst.

Which of the following classes of chemical messengers is able to easily diffuse across the cell membrane?

Steroids

Interleukins

Catecholamines

Histamines

Steroids

Steroids are lipid-soluble. Therefore, they are able to diffuse across the hydrophobic cell membrane.

A gene is being copied into a molecule that contains ribose and uracil. Which of the following cellular processes does this describe?

DNA replication

Translation

Gene splicing

Transcription

Transcription

Transcription is the process by which a gene, encoded in DNA, is copied into a messenger RNA. RNA contains ribose sugar and uracil base.

Which of the following statements are true regarding the lymphatic system?

It is a closed circulatory system.

The lymph flows from the interstitial spaces toward the heart.

The lymph transports carbon dioxide to the lungs for expiration.

The lymphatic systems helps the body to absorb lipids.

The lymphatic system contains more red blood cells than white blood cells.

The lymph flows from the interstitial spaces toward the heart is correct.

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The lymphatic system contains a clear fluid called lymph that flows in one direction from the interstitial spaces toward the lymph ducts that then empty into the veins to enter the circulatory system and travel toward the heart.

The lymphatic system helps the body to absorb lipids is correct.

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Lymphatic vessels, called lacteals, absorb dietary lipids from the small intestine.

Which of the following will occur in the absence of melanocytes in the skin?

The skin will have a thin dermis.

The skin will not have pigmentation.

The skin will get tanned on exposure to sunlight.

The skin will not be able to maintain its temperature.

The skin will not have pigmentation.

Melanocytes produce the pigment called melanin, which gives skin its color. In the absence of melanocytes, the skin will not be able to produce the pigment melanin and will have a pale and white appearance.

Which of the following hormones requires iodine for its production?

Thyroid hormones

Melatonin

Parathyroid hormone

Calcitonin

Thyroid hormones

The human body needs iodine, a naturally occurring element, to produce the thyroid hormones thyroxine and triiodothyronine.

Which of the following is the role of the urethra?

To transport urine out of the body

To transport the egg to the uterus

To connect the kidneys to the bladder

To connect the uterus to the outside of the body

To transport urine out of the body

The urethra connects the bladder to the opening of the body and allows the urine to exit the body.

Which of the following terms describes the bonding together of smaller molecules to form larger molecules?

Anabolism

Catalysis

Catabolism

Anaphylaxis

Anabolism

Anabolism describes the endothermic process by which bonds are formed between molecules to make larger molecules.

Which of the following is a characteristic feature of the adaptive immune system?

It uses phagocytes for the ingestion of foreign particles.

It produces antibodies against a specific antigen in the body.

It exerts the first response of the immune system against an infection.

It is comprised of non-specific barriers against a pathogen.

It produces antibodies against a specific antigen in the body.

The adaptive immune system contains B cells, which differentiate into plasma cells, which produce antibodies against specific antigens.

after doing a belly flop into a swimming pool, a child says, " the water slapped me." what is the property of water that causes the slap?

Irregular expansion

Hydrogen bonding

Capillary action

Hydrophobic exclusion

Hydrogen bonding

Hydrogen bonding holds the water molecules tightly together so they cannot disperse easily, increasing surface tension and causing the slap.

Which of the following is true of centromeres of mitotic chromosomes prior to anaphase?

It is the region where sister chromatids are most closely attached.

It is the region where crossing over occurs.

It is the region where replication begins.

It is the region where histones are made.

It is the region where sister chromatids are most closely attached.

A centromere is a specialized region where two chromatids are most closely attached.

Which of the following occurs when a skeletal muscle is in a relaxed state?

Tropomyosin covers myosin-binding sites.

Myosin forms cross bridges with actin filaments.

Ca2+ is released into the cytosol of the muscle cell.

ATP binds to myosin heads.

Tropomyosin covers myosin-binding sites.

When a muscle is in a relaxed state, tropomyosin covers myosin-binding sites on actin.

Which of the following cell organelles are abundant in nerve and muscle cells to help meet their ATP requirements?

Endoplasmic reticulum

Mitochondria

Golgi bodies

Nucleus

Mitochondria

Mitochondria play a role in cellular respiration and help generate ATP, which provides cellular energy to carry out different functions.

Which of the following is the function of the spleen in a healthy adult human?

It stores bile produced in the liver.

It synthesizes platelets.

It is a vestigial organ.

It degrades aged red blood cells.

It degrades aged red blood cells.

A healthy spleen has narrow tubes that cause aged red blood cells to rupture as they try to squeeze through.

Which of the following correctly describes the color change and substance properties for acid-base indicator testing?

Blue litmus turns red, indicating the presence of a base with a pH > 7.

Red litmus turns blue, showing the presence of an acid with a pH > 7.

Blue litmus turns red, indicating the presence of an acid with a pH < 7.

Red litmus turns blue, showing the presence of a base with a pH < 7.

Blue litmus turns red, indicating the presence of an acid with a pH < 7.

Blue litmus would turn red with an acid, and acids have a pH less than 7.

Which of the following molecules present in blood has the ability to buffer changes in pH?

Cholesterol

Bicarbonate

Plasma sugars

Circulating salts

Bicarbonate

Bicarbonate is the conjugate base of carbonic acid, which is made from water and carbon dioxide, both of which are present in abundance in blood. Therefore, bicarbonate is a buffer in conjunction with carbonic acid.

Which of the following correctly describes physical changes between states of matter?

Deposition occurs when the water in a lake changes to ice.

Evaporation occurs when candle wax burns to form smoke.

Condensation occurs when glue solidifies with exposure to air.

Sublimation occurs when dry ice turns into carbon dioxide gas.

Sublimation occurs when dry ice turns into carbon dioxide gas.

Sublimation is the conversion of a solid into a gas without passing through a liquid stage. Since carbon dioxide goes from a solid phase to a gaseous phase, this process is sublimation.

The process known as gastrulation results in the formation of which of the following embryonic structure?

Germ layers

Circulatory system

Neural crest

Limb buds

Germ layers

The gastrula derives from invagination of the blastula early in development and is the structure in which the germ layers (the ectoderm, mesoderm, and endoderm) are laid down.

A student conducts an experiment in which he dissolves 1.0 grams each of several substances in 50 millimeters of water. He has 12 identical plastic cups of water. He places 1.0 grams of salt into three of the cups, 1.0 grams of sugar into three of the cups and 1.0 grams of backing soda into three of the cups. The three remaining cups contain only water. He places all of the cups in a freezer and records the temperature of the water in each cup every 15 minutes for 4 hours. Which of the following questions is the student most likely testing?

Pie chart

Bar graph

Venn diagram

Line graph

line graph

Changes over time are best represented by a line graph.

Which of the following describes the function of the ribosome in a cell?

Production of ATP molecules from energy in nutrient molecules

Disposal and recycling of damaged or unneeded cell parts

Use of genetic information to build specific protein molecules

Regulation of molecules entering and leaving the cell

Use of genetic information to build specific protein molecules

The ribosome is the site of translation of the genetic code of DNA and RNA into the amino acid code of proteins.

Which of the following connects the ovaries to the uterus?

Vas deferens

Ureters

Fallopian tubes

Urethra

Fallopian tubes

The fallopian tubes connect the ovaries to the uterus.

An infant's immune system is immature at the time of birth. They receive their birthing parent's antibodies through the placenta before birth and from breast milk after birth. Which of the following terms can be used to describe this type of immunity?

Active immunity

Adaptive immunity

Innate immunity

Passive immunity

Passive immunity

Passive immunity is an immune response in which antibodies are directly obtained from outside the body. Examples of passive immunity include immunoglobulin therapy and the transfer of antibodies from the birthing parent through the placenta and breast milk.

Which of the following outcomes will most likely result from an increase in population's level of education and standard of living and an improvement in educational and employment opportunities for women?

Increase in the population's average female fertility

Increase in the population's death rate

Decrease in the population's life expectancy

Decrease in the population's birth rate

Decrease in the population's birth rate

A decrease in birth rates usually is a consequence with women being engaged with work and education. Typically, fertility rates and women's empowerment are inversely proportional.

Which of the following is improved when repeated trials of an experiment have consistent results?

Reliability

Validity

Independent variables

Dependent variables

Reliability

Which of the following is a chemical property, as opposed to a physical property, of water?

Ice is less dense than, and floats on, liquid water.

Water can be decomposed into hydrogen and oxygen gas.

Water has a high surface tension due to hydrogen bonding.

Bonds between water molecules can be broken by heating.

Water can be decomposed into hydrogen and oxygen gas.

Making and breaking of bonds between atoms in a molecule indicate a chemical reaction.

Which of the following is an example of a long bone?

Vertebra

Sacrum

Ribs

Femur

femur

A patient that has a mutation that causes type 1 diabetes mellitus is trying a therapy that will use their own somatic stem cells to restore their insulin production. Before their stem cells can be used for therapy, which of the following should be done?

The stem cells should be inactivated with UV radiation.

A normal gene should be supplied in place of the defective one before therapy.

The patient should be advised that the genetically altered cells will be passed on to offspring.

The patient should be tested to ensure that their body will not reject the stem cells.

A normal gene should be supplied in place of the defective one before therapy.

The patient's insulin-producing genes are damaged. A functional insulin-producing gene should be placed into the cells with the aim of integrating the gene into the DNA.

In humans, A and B alleles are codominant over O to determine blood type. Which of the following combinations of parental genotypes has the greatest probability of producing a child with type AB blood?

AB and BO

AO and BO

AB and AB

AA and BB

AA and BB

Which of the following is an example of a nonspecific action of the immune system?

Plasma cells produce antibodies to attack foreign cells.

Memory T-cells are produced in response to vaccines.

Inflammation is initiated in response to infection.

Cytotoxic T-cells are activated to attack infected cells.

Inflammation is initiated in response to infection.

Inflammation is a nonspecific response to an infection and results in redness, fever, swelling, and pain at the site of infection.

Which of the following diseases in primarily caused by a toxin produced by a microorganism?

Cholera

Leprosy

Acne

HIV

Cholera

Diarrhea associated with cholera is caused by cholera toxin secreted by certain strains of the bacterium Vibrio cholerae.

In which of the following parts of the digestive system is vitamin B12 absorbed?

Stomach

Pancreas

Large intestine

Small intestine

small intestine

Vitamin B12 is absorbed in the distal ileum of the small intestine by receptor-mediated endocytosis.

Which of the following is the collagen-rich material that connects muscle to bone?

Tendon

Ligament

Reticular tissue

Areolar tissue

Tendon

Tendons connect muscle to bone. For example, the Achilles tendon connects the lower leg muscles to the heel bone.

A student wants to design an experiment to demonstrate the affects of acid rain on plant life. Which of the following substances should be combined with water to simulate acid rain?

Vinegar

Table salt

Baking soda

Ammonia

vinegar

Vinegar is acidic, with a pH less than 7. Adding it to water will acidify water to simulate acid rain.

The growth in human population size is one of the reasons for the rise in global temperatures. Arrange the steps in the logical order of events to show their casual relationships.

Increase in greenhouse gas emissions

Increase in population size

Increase in heat trapped in atmosphere

Increase in atmospheric temperatures

Increase in the use of fossil fuels

Increase in population size is the first event.

Increase in the use of fossil fuels is the second event.

Increase in greenhouse gas emissions is the third event.

Increase in the heat trapped in the atmosphere is the fourth event.

Increase in atmospheric temperatures is the fifth event. Trapped heat leads to increased atmospheric temperatures.

Which of these substances will best dissolve in water?

CH4

CCl4

HCl

N2

HCl

HCl is an ionic compound and dissociates into charged particles called ions. Because water molecules are polar, water is a good solvent for ions.

Which of the following results from the release of the neurotransmitter dopamine into the nerve synapse?

The presynaptic neuron fires an action potential.

Dopamine binds to receptor proteins on the membrane of the postsynaptic cell.

Dopamine enters the cytoplasm of the postsynaptic cell.

Dopamine causes the postsynaptic nerve cell to contract.

Dopamine binds to receptor proteins on the membrane of the postsynaptic cell.

Dopamine binds to receptor proteins on the membrane of the postsynaptic cell.

When dopamine enters the synapse, it binds to receptor proteins of the postsynaptic cell, causing a response in the cell. Dopamine is a polar molecule that acts by binding to receptors on the postsynaptic neuron.

Which of the following temperature scales is 0 degrees equal to the freezing point of water?

Kelvin

Fahrenheit

Celsius

Newton

Celsius

The freezing point of water in Celsius is 0°.

Which of the following is a function of a somatic reflex?

It helps to produce an involuntary response in the absence of a stimulus.

It helps to produce a response quickly to protect the body from harm.

It helps to produce variable responses to the same sensory input.

It helps the individual to produce an appropriate voluntary response.

It helps to produce a response quickly to protect the body from harm.

Reflex actions are involuntary, stereotyped, and predictable, as they require the body to respond quickly to a specific sensory input to protect the body.

A field containing a single variety of commercial bananas is devastated by a virus. Nearby, wild banana groves with similar plant densities show infection, but many plants remain healthy. Which of the following statements best explains this observation?

Crowded fields lead to higher plant stress and greater susceptibility to infection.

Density-dependent shading in the commercial fields leads to rapid spread of viruses in damp soil.

Wild bananas have more genetic variation, and some plants are resistant to the banana virus.

Commercial bananas are genetically modified and less robust than wild bananas.

Wild bananas have more genetic variation, and some plants are resistant to the banana virus.

A single variety is a clone of a high-yielding plant, and it has no genetic variation. All the cloned plants are susceptible to the virus. Variation is a prerequisite of adaptation to changing environments.

Which of the following methods could be used to determine how much volume is taken up by rocks placed in a container?

Mass the container; mass the container with the rocks in it; calculate the difference in these two masses.

Count the number of rocks; mass the rocks; then divide the mass of the rocks by the number of rocks.

Fill the container to capacity with water; add rocks to the container; collect the water that overflows and mass it.

Mass the container empty; fill it with the rocks and water; then mass it again and find the difference.

Fill the container to capacity with water; add rocks to the container; collect the water that overflows and mass it.

The volume of the container is approximated by filling it with water. Adding rocks to the container displaces an equal volume of water. Therefore, the water that spills out of the container will equal the volume of the rocks. This question assumes that the rocks are more dense than water.

Which of the following explains what happens in the circulatory system during hyperventilation?

Oxygen levels increase, causing an increase in blood pH.

Carbon dioxide levels decrease, causing an increase in blood pH.

Oxygen levels decrease, causing a decrease in blood pH.

Carbon dioxide levels increase, causing a decrease in blood pH.

Carbon dioxide levels decrease, causing an increase in blood pH.

As carbon dioxide levels decrease, the blood becomes more basic, increasing blood pH.