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OGT Type Questions Part II. Science. A molecule of DNA is "packaged" and carried by a larger molecule called a __________. A. Nucleus B. Vacuole C. Chromosome D. Gene. A molecule of DNA is "packaged" and carried by a larger molecule called a __________. Answer: C
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OGT Type QuestionsPart II Science
A molecule of DNA is "packaged" and carried by a larger molecule called a __________. • A. Nucleus • B. Vacuole • C. Chromosome • D. Gene
A molecule of DNA is "packaged" and carried by a larger molecule called a __________. • Answer: C • A molecule of DNA is "packaged" and carried by a larger molecule called a chromosome. In a chromosome, a single strand of DNA is wound and coiled many times around a variety of proteins. In this way, a chromosome functions as a method of "packaging" the DNA, which would be extremely long if it existed as an independent strand (if the DNA in a human cell were stretched out, it would be about 6 feet long!).
Every trait you see on an organism is a result of that organism’s DNA instructing the organism’s cells. How does the information stored in DNA’s nucleotides translate into traits such as eye color and ear shape? • A. Traits are determined by proteins that are built according to the instructions stored in genes. • B. Traits are determined by a group of enzymes known as DNA helicases. • C. Traits are determined by codons that are stored in groups of nucleotides. • D. Traits are determined by the presence or absence of lac operons along a series of nucleotides.
Every trait you see on an organism is a result of that organism’s DNA instructing the organism’s cells. How does the information stored in DNA’s nucleotides translate into traits such as eye color and ear shape? • Answer: A • Proteins have many functions, including acting as enzymes and cell membrane channels. All of the proteins in the body are built from amino acids according to very specific instructions stored in the genes on DNA molecules. Proteins are not built directly from DNA, though. RNA is involved in protein synthesis, which is also known as gene expression.
DNA contains all the information a cell needs in order to make certain proteins. Where are the protein-synthesizing instructions stored on a DNA molecule? • A. The deoxyribose portion of certain genes code for the production of certain proteins. • B. Every gene on certain chromosomes code for the production of different kinds of uracil, which then promotes protein synthesis. • C. The nucleotides of certain genes code for the production of specific proteins. • D. The phosphate group in a strand of DNA codes for the production of amino acids.
DNA contains all the information a cell needs in order to make certain proteins. Where are the protein-synthesizing instructions stored on a DNA molecule? • Answer: C • A gene’s instructions for making a protein are coded in the sequence of nucleotides in the gene. The instructions for making a protein are transferred from a gene to an RNA molecule during transcription. Amino acids are joined together into specific proteins during translation. This process is known as gene expression.
When a cell needs a particular protein synthesized, messenger RNA (mRNA) is produced from DNA through transcription. How is genetic information stored in mRNA? • A. As amino acids • B. As codons • C. As ribose • D. As uracil
When a cell needs a particular protein synthesized, messenger RNA (mRNA) is produced from DNA through transcription. How is genetic information stored in mRNA? • Answer: B • RNA information is stored in an RNA molecule as a series of three-nucleotide sequences on the mRNA called codons. Each codon along the mRNA strand corresponds to an amino acid or signifies a start or stop signal for translation.
In DNA, the structure and size of the four nitrogen bases allows only for one kind of base to pair with one other kind. This is called the base-pairing rule. Which of the following shows how bases pair in complementary strands of DNA? • A. A-A and T-T • B. A-T and C-G • C. A-G and T-C • D. A-C and T-G
In DNA, the structure and size of the four nitrogen bases allows only for one kind of base to pair with one other kind. This is called the base-pairing rule. Which of the following shows how bases pair in complementary strands of DNA? • Answer: B • Adenine (A) forms two hydrogen bonds with thymine (T), and cytosine (C) forms three hydrogen bonds with guanine (G). The hydrogen bonds between the bases keep the two strands of DNA together.
A molecule of DNA is "packaged" and carried by a larger molecule called a __________. • A. Gene • B. Dipold • C. Chromosome • D. Vacuole
A molecule of DNA is "packaged" and carried by a larger molecule called a __________. • Answer: C • A molecule of DNA is "packaged" and carried by a larger molecule called a chromosome. In a chromosome, a single strand of DNA is wound and coiled many times around a variety of proteins. In this way, a chromosome functions as a method of "packaging" the DNA, which would be extremely long if it existed as an independent strand (if the DNA in a human cell were stretched out, it would be about 6 feet long!).
Which of the following is true about genes? • A. The genes of a particular organism can never change throughout its lifetime. • B. In humans, genes are passed to an offspring from two parents. • C. Genes are made up of smaller molecules known as chromosomes. • D. Genes are responsible for all the traits of an organism.
Which of the following is true about genes? • Answer: B • In humans and many other sexually-reproducing organisms, genes are passed to an offspring from two parents. Half of a child's genetic information comes from his/her mother and the other half comes from • his/her father. • Genes are not responsible for all the traits of an organism. Some of the traits of an organism are a result of environmental factors, such as diet, for example. Genes are responsible for all the inherited traits of an organism. • The genes of a particular organism can change throughout its lifetime. Such a change is known as a mutation. • Genes are not made up of chromosomes. Chromosomes are made up of genes.
An allele is one of the alternative forms of a gene that governs a trait. If a fern plant is heterozygous for a particular trait, how can the alleles that control that trait be described? • A. One dominant, one recessive • B. Two dominant recessive • C. Three recessive, one dominant • D. Two recessive
An allele is one of the alternative forms of a gene that governs a trait. If a fern plant is heterozygous for a particular trait, how can the alleles that control that trait be described? • Answer: A • If the two alleles of a particular gene present in an individual are the same, the individual is said to be homozygous. If the alleles of a particular gene present in an individual are different, the individual is heterozygous for that trait.
Select the choice that best completes the following sentence:A normal human has a total of ___ chromosomes: ___ chromosomes come from the mother and ___ chromosomes come from the father. • A. 50, 25, 25 • B. 46, 23, 23 • C. 23, 12, 11 • D. 92, 46, 46
Select the choice that best completes the following sentence:A normal human has a total of ___ chromosomes: ___ chromosomes come from the mother and ___ chromosomes come from the father. • Answer: B • A normal human has a total of 46 chromosomes: 23 chromosomes come from the mother and 23 come from the father
A female rabbit had five offspring in one litter. Two of the five baby rabbits were able to survive into adulthood. Why are some animals more likely to survive to adulthood than other animals? • A. They are able to sense and respond to their environment better. • B. They are able to avoid adaptation better. • C. They are able to evolve faster than the other animals. • D. They are able to have more offspring than other animals.
A female rabbit had five offspring in one litter. Two of the five baby rabbits were able to survive into adulthood. Why are some animals more likely to survive to adulthood than other animals? • Answer: A • The survival of an organism depends on its ability to sense and respond to its external environment. Adaptations help an organism respond successfully to its environment. If an organism is able to survive into adulthood, it will be able to have offspring and pass on its genes.
What is the smallest particle of an element? • A. Mixture • B. Compound • C. Molecule • D. Atom
What is the smallest particle of an element? • Answer: D • An atom is the smallest part of an element that still has all the properties of the element.
Which subatomic particle has the greatest mass? • A. Proton • B. Neutron • C. Ion • D. Electron
Which subatomic particle has the greatest mass? • Answer: B • The neutron is the subatomic particle with the greatest mass. A proton has about 99% of the mass of a neutron and an electron is about 0.054 as massive as a neutron.
The nucleus of an atom consists of _____ • A. protons and electrons • B. Neutrons and electrons • C. protons and neutrons • D. neutrons alone
The nucleus of an atom consists of _____ • Answer: C • The nucleus of an atom contains protons and neutrons. Electrons are found outside of an atom’s nucleus.
The sum of the protons and neutrons in an atom is its _____ . • A. charge • B. atomic energy • C. atomic number • D. atomic mass
The sum of the protons and neutrons in an atom is its _____ • Answer: D • An element's atomic mass is the sum of the protons and neutrons in the nucleus of one atom of the element.
The atomic mass of Silver (Ag) is 107 and the atomic number of silver is 47. How many neutrons does a neutral atom of Silver contain? • A.24 • B. 47 • C. 107 • D. 60
The atomic mass of Silver (Ag) is 107 and the atomic number of silver is 47. How many neutrons does a neutral atom of Silver contain? • Answer: D • The atomic mass of an element is equal to the number of protons plus the average number of neutrons found in a neutral atom. An element’s atomic number is equal to the number of protons an element contains. Accordingly, the number of neutrons in a neutral atom of Silver can be calculated as the atomic mass minus the atom number. 107 minus 47 is equal to 60.
If an atom has 17 protons, 16 neutrons, and 20 electrons, what is the atom's electrical charge? • A.+4 • B. +1 • C. -3 • D. -1
If an atom has 17 protons, 16 neutrons, and 20 electrons, what is the atom's electrical charge? • Answer: C • Each proton has a charge of (+1), each electron has a charge of (-1), and each neutron has a neutral charge. Add up the charges in the atom: 17 + (-20) = -3
The chemical combination of two or more elements in fixed amounts is called a _____ . • A.mixture. • B. compound • C. ion • D. element
The chemical combination of two or more elements in fixed amounts is called a _____ . • Answer: B • The chemical combination of two or more elements is called a compound.
Two negatively charged ions react and a compound is formed. The compound has ____ bonding. • A.ionic • B. metallic • C. covalent • D. regular
Two negatively charged ions react and a compound is formed. The compound has ____ bonding. • Answer: C • Covalent bonding occurs when two atoms share electrons. Electrons are shared between negatively charged ions.
Which element would form a covalent bond when reacted with oxygen? • A.magnesium • B. sulfur • C. iron • D. lead
Which element would form a covalent bond when reacted with oxygen? • Answer: B • Covalent bonds form when two negative ions share electrons. Oxygen and sulfur are both negative ions and would form a compound with covalent bonding. The other compounds would have ionic bonding, where electrons would be transferred to the oxygen atom.
Which compound has ionic bonding? • A.Cl2 • B. NO2 • C. CaO • D. HF
Which compound has ionic bonding? • Answer: C • Ionic bonding occurs between a positively charged ion and a negatively charged ion, with electrons transferred between atoms. In this case, Ca2+ is a positive ion and donates two electrons to the negative O2- ion. This creates an ionic bond. The other three compounds have covalent bonds, with electrons shared between negative ions.
Density refers to a physical property that is measured using a ratio of _______ divided by _______ so that two objects of the same size can still have very different density. • A.height, width • B. Weight, height • C. concentration, mass • D. mass, volume
Density refers to a physical property that is measured using a ratio of _______ divided by _______ so that two objects of the same size can still have very different density. • Answer: D • Density is a measure of how much matter is packed into an object of its size. Density = mass (amount of matter in an object) divided by volume (the total amount of space a substance occupies).
Which of the following items best embodies the physical property of conductivity? • A. A diamond that is not easily scratched. • B.A copper penny that easily transmits electricity. • C.A teak log that has a large amount of mass for its volume. • D.A white cotton shirt that reflects all wavelengths of light.
Which of the following items best embodies the physical property of conductivity? • Answer: B • Copper has a high conductivity and electricity travels through it well. Diamonds, wood, and fabric have low conductivity.
The Mohs scale, which distinguishes a mineral’s resistance to being scratched, measures which physical property of substances? • A.Concentration • B. Ductility • C. Hardness • D. Conductivity
The Mohs scale, which distinguishes a mineral’s resistance to being scratched, measures which physical property of substances? • Answer: C • The Mohs scale is a hardness scale used to distinguish one mineral from one another. The scale ranges from the soft, easy to scratch talc at 1 to the extremely hard diamond at 10. The higher the number, the harder the mineral is to scratch.
Which of the following materials has the highest ductility? • A.A diamond • B. A piece of copper • C. A marble • D. A piece of wood
Which of the following materials has the highest ductility? • Answer: B • Ductility is a measure of how easily a substance is elongated, stretched, or otherwise permanently changed in shape without breaking. Copper is the only substance mentioned which can be easily elongated and stretched to form a wire.
Newton's _______ Law of Motion states that "An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force." • A.Third • B. Second • C. First • D. Fourth