Which of the following represents the complementary strand of a DNA sequence 3' TCGATCGCA 5'?
A. 3' AGCTAGCGT 5'
B. 5’ AGCTAGCGT 3’
C. 5' UCGAUCGCA 3'
D. 3' TCGUTCGCU 3'
In DNA, the nitrogenous bases adenine (A) and thymine (T) pair together, while cytosine (C) and guanine (G) pair together.
Therefore, the complementary strand of the given DNA sequence 3' TCGATCGCA 5' would have the complementary nitrogenous bases as:
5’ AGCTAGCGT 3’
NOTE: The 5’ to 3’ direction of the complementary strand is opposite to that of the given strand.
Choice A.
3’ AGCTAGCGT 5’ is not correct because it is not complementary to the given strand.
Choice C.
5’ UCGAUCGCA 3’ is not correct because it contains uracil (U), which is a nitrogenous base found in RNA, not DNA.
Choice D.
3’ TCGUTCGCU 3’ is not correct because it also contains uracil (U), which is a nitrogenous base found in RNA, not DNA.
Therefore, the Correct Answer is B.
More Questions on TEAS 7 Science
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Q #1: Which of the following structures is present in both prokaryotic and eukaryotic cells?
A. Cell membrane
B. Golgi apparatus
C. Chloroplasts
D. Endoplasmic reticulum
Answer Explanation
The cell membrane is present in both prokaryotic and eukaryotic cells.
The cell membrane is a thin, flexible barrier that surrounds all cells and separates the inside of the cell from the outside environment.
It is composed of a lipid bilayer and regulates the movement of substances into and out of the cell.
Choice B is incorrect because the Golgi apparatus is not present in prokaryotic cells.
The Golgi apparatus is an organelle found in eukaryotic cells that is involved in modifying, sorting, and packaging proteins and lipids for transport to other parts of the cell or to be secreted outside the cell.
Choice C is incorrect because chloroplasts are not present in prokaryotic cells.
Chloroplasts are organelles found in plant cells and some algae that are responsible for photosynthesis.
Choice D is incorrect because the endoplasmic reticulum is not present in prokaryotic cells.
The endoplasmic reticulum is an organelle found in eukaryotic cells that is involved in protein synthesis and lipid metabolism.
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Q #2: Which of the following glands synthesizes antidiuretic hormone?
A. Pineal gland
B. Thymus
C. Hypothalamus
D. Pancreas
Answer Explanation
The hypothalamus is a region of the brain that synthesizes antidiuretic hormone (ADH), also known as vasopressin.
ADH is then transported to the posterior pituitary gland via neurohypophysial capillaries, where it is stored until it is ready to be secreted into the circulation.
Choice A.
Pineal gland is not correct because it is a small endocrine gland located in the brain that secretes the hormone melatonin, which regulates sleep-wake cycles, but it does not synthesize ADH.
Choice B.
Thymus is not correct because it is a gland located in the chest that produces hormones involved in immune system development, but it does not synthesize ADH.
Choice D.
Pancreas is not correct because it is a gland located behind the stomach that secretes hormones such as insulin and glucagon, which regulate blood sugar levels, but it does not synthesize ADH.
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Q #3: Which of the following vessels carries oxygenated blood?
A. Superior vena cava
B. Inferior vena cava.
C. Pulmonary artery
D. Pulmonary vein
Answer Explanation
The pulmonary veins are the vessels that carry oxygenated blood from the lungs to the left atrium of the heart.
Choice A is not correct because the superior vena cava carries deoxygenated blood from the upper body to the right atrium of the heart.
Choice B is not correct because the inferior vena cava carries deoxygenated blood from the lower body to the right atrium of the heart.
Choice C is not correct because the pulmonary artery carries deoxygenated blood from the right ventricle of the heart to the lungs.
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Q #4: Which of the following represents the complementary strand of a DNA sequence 3' TCGATCGCA 5'?
A. 3' AGCTAGCGT 5'
B. 5’ AGCTAGCGT 3’
C. 5' UCGAUCGCA 3'
D. 3' TCGUTCGCU 3'
Answer Explanation
In DNA, the nitrogenous bases adenine (A) and thymine (T) pair together, while cytosine (C) and guanine (G) pair together.
Therefore, the complementary strand of the given DNA sequence 3' TCGATCGCA 5' would have the complementary nitrogenous bases as:
5’ AGCTAGCGT 3’
NOTE: The 5’ to 3’ direction of the complementary strand is opposite to that of the given strand.
Choice A.
3’ AGCTAGCGT 5’ is not correct because it is not complementary to the given strand.
Choice C.
5’ UCGAUCGCA 3’ is not correct because it contains uracil (U), which is a nitrogenous base found in RNA, not DNA.
Choice D.
3’ TCGUTCGCU 3’ is not correct because it also contains uracil (U), which is a nitrogenous base found in RNA, not DNA.
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Q #5: In a hypertonic solution, water flows through aquaporins embedded in the plasma membrane of the cell. This type of transport is best known as which of the following?
A. Facilitated diffusion
B. Active transport
C. Osmosis
D. Diffusion
Answer Explanation
Osmosis is the movement of water molecules across a selectively permeable membrane from an area of higher water concentration to an area of lower water concentration.
In a hypertonic solution, the concentration of solutes outside the cell is higher than inside the cell, so water flows out of the cell through aquaporins embedded in the plasma membrane to balance the concentration gradient.
Choice A.
Facilitated diffusion is not correct because it is a type of passive transport that involves the movement of molecules across a membrane through specific transport proteins, but it does not specifically refer to the movement of water molecules.
Choice B.
Active transport is not correct because it is a type of transport that involves the movement of molecules against their concentration gradient and requires energy in the form of ATP, but osmosis is a passive process that does not require energy.
Choice D.
Diffusion is not correct because it refers to the movement of molecules from an area of higher concentration to an area of lower concentration, but it does not specifically refer to the movement of water molecules.
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Q #6: The measurement indicated by the line across the center of the cell is best referred to as which of the following?
A. Area.
B. Diameter.
C. Volume.
D. Radius.
Answer Explanation
Diameter.
The diameter is the measurement of a straight line passing through the center of a circle and connecting two points on its circumference.
In this case, the line across the center of the cell represents the diameter of the cell.
Choice A, Area, is not the correct answer because area refers to the amount of space inside a two-dimensional shape.
Choice C, Volume, is not the correct answer because volume refers to the amount of space occupied by a three-dimensional object.
Choice D, Radius, is not the correct answer because radius refers to the distance from the center of a circle to its circumference and is half the length of the diameter.
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Q #7: What is the approximate threshold value for mammalian neurons?
A. -55 mV
B. -80 mV
C. +35 mV
D. 0 mV
Answer Explanation
The approximate threshold value for mammalian neurons is -55 mV.
The threshold potential is the critical level to which a membrane potential must be depolarized to initiate an action potential.
Most often, the threshold potential is a membrane potential value between –50 and –55 mV
The membrane potential of a neuron is determined by the distribution of ions across the cell membrane.
At rest, the inside of a neuron is more negative than the outside due to the presence of negatively charged proteins and other molecules.
The movement of ions across the cell membrane can change the membrane potential.
For example, when sodium ions enter the cell, they make the inside of the cell more positive (less negative), causing depolarization.
Choice B is incorrect because -80 mV is below the typical threshold value for mammalian neurons.
Choice C is incorrect because +35 mV is above the typical threshold value for mammalian neurons.
Choice D is incorrect because 0 mV is above the typical threshold value for mammalian neurons.
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Q #8: Which of the following are the two major parts of the nervous system?
A. Autonomic nervous system and somatic nervous system.
B. Peripheral nervous system and somatic nervous system
C. Peripheral nervous system and central nervous system.
D. Autonomic nervous system and central nervous system.
Answer Explanation
The two major parts of the nervous system are the Central Nervous System (CNS) and the Peripheral Nervous System (PNS).
The CNS is made up of the brain and spinal cord and acts as the integration and command center of the body.
The PNS represents the conduit between the CNS and the body and is further subdivided into the somatic nervous system (SNS) and the autonomic nervous system (ANS).
Choice A is incorrect because it only mentions two subdivisions of the PNS, which are the autonomic nervous system (ANS) and somatic nervous system (SNS).
Choice B is incorrect because it only mentions one major part of the nervous system, which is the PNS, and one subdivision of it, which is the SNS.
Choice D is incorrect because it only mentions one major part of the nervous system, which is the CNS, and one subdivision of the PNS, which is the ANS.
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Q #9: Nitrogen gas is an extremely stable molecule because of which of the following?
A. Ionic bonds
B. Hydrogen bonds
C. Resonance bonds
D. Triple covalent bonds
Answer Explanation
Triple covalent bonds.
Nitrogen gas (N2) is an extremely stable molecule because it consists of two nitrogen atoms bonded together by a triple covalent bond.
A covalent bond is a type of chemical bond where atoms share electrons to form a molecule.
In a triple covalent bond, three pairs of electrons are shared between the two atoms, resulting in a very strong bond that makes the molecule extremely stable.
Choice A.
Ionic bonds is not correct because ionic bonds involve the transfer of electrons from one atom to another to form ions, which are then attracted to each other due to their opposite charges.
Nitrogen gas does not contain ions and is not held together by ionic bonds.
Choice B.
Hydrogen bonds is not correct because hydrogen bonds are weak electrostatic attractions between molecules that contain hydrogen atoms bonded to highly electronegative atoms such as oxygen or nitrogen.
Nitrogen gas does not contain hydrogen atoms and is not held together by hydrogen bonds.
Choice C.
Resonance bonds is not correct because resonance refers to the delocalization of electrons in a molecule where multiple Lewis structures can be drawn to represent the molecule.
Nitrogen gas has a single Lewis structure and does not exhibit resonance.
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Q #10: Stimulus: 1of 1. A group of students performed an experiment to test terminal velocity, which is the greatest speed obtained by a falling object. The students dropped different numbers of coffee filters and measured the resulting terminal velocity. Which of the following conclusions is supported by the data in the following data table? #OF FILTERS MASS (g) TERMINAL VELOCITY (m/s) 1 1.01 1.74 2 1.99 2.48 3 3.02 3.04 4 4.0 3.50 5 5.01 3.80
A. Terminal velocity is when the force of gravity is equal to air resistance.
B. Heavier objects take more time to reach terminal velocity.
C. Heavier objects fall faster than lighter objects.
D. The greater the number of filters, the smaller the terminal velocity.
Answer Explanation
Heavier objects fall faster than lighter objects.
The data in the table shows that as the number of filters (and therefore the mass) increases, the terminal velocity also increases.
This means that the heavier objects (with more filters) are falling faster than the lighter objects (with fewer filters).
Choice A is not supported by the data in the table as much as it is true.
Terminal velocity is indeed when the force of gravity is equal to air resistance, but this definition does not provide any information about the relationship between mass and terminal velocity.
Choice B is also not supported by the data in the table.
The data does not provide any information about the time it takes for an object to reach terminal velocity.
Choice D is not supported by the data in the table.
The data shows that as the number of filters increases, the terminal velocity also increases.
This means that the greater the number of filters, the greater (not smaller) the terminal velocity.
