1.
If a pea plant were homozygous recessive for height, how would its alleles be represented?
Correct Answer
C. Tt
Explanation
If a pea plant is homozygous recessive for height, it means that both of its alleles for height are recessive. In this case, the alleles would be represented as "tt". The lowercase "t" indicates the recessive allele for height.
2.
When an organism has two alleles at a particular locus that are different, the organism is called
Correct Answer
C. Heterozygous
Explanation
When an organism has two alleles at a particular locus that are different, the organism is called heterozygous. Heterozygous means that the organism carries two different versions of a gene, one from each parent. This is in contrast to purebred, which refers to an organism that carries two identical alleles, and dominant and recessive, which describe the relationship between different alleles in determining a trait.
3.
Hair color and eye color are examples of a person's
Correct Answer
D. pHenotype.
Explanation
Hair color and eye color are examples of a person's phenotype. Phenotype refers to the observable physical characteristics of an individual, which are determined by a combination of genetic factors (genotype) and environmental influences. Hair color and eye color are traits that can be easily observed and are influenced by the interaction of multiple genes. Therefore, they are considered examples of an individual's phenotype.
4.
Mendel's second law of genetics, the law of independent assortment, is one explanation of the
Correct Answer
B. Genetic variation within species.
Explanation
Mendel's second law of genetics, the law of independent assortment, states that during gamete formation, the segregation of one pair of alleles is independent of the segregation of another pair. This means that different traits are inherited independently from each other. This process leads to the creation of new combinations of alleles in offspring, resulting in genetic variation within a species.
5.
Any of the alternative forms of a gene that occurs at a specific place on a chromosome are known as ___.
Correct Answer
A. Alleles
Explanation
Alleles are alternative forms of a gene that occur at a specific place on a chromosome. They are responsible for the variations in traits that individuals can have. Each individual inherits two alleles for each gene, one from each parent. These alleles can be dominant or recessive, and they determine the expression of specific traits in an individual. Therefore, alleles are the correct answer because they represent the different variations of a gene that can exist at a specific location on a chromosome.
6.
A chart or "family tree" that tracks which members of a family have a particular trait is called a ___.
Correct Answer
A. Pedigree
Explanation
A chart or "family tree" that tracks which members of a family have a particular trait is called a pedigree. Pedigrees are commonly used in genetics to analyze the inheritance patterns of traits and to determine if they are caused by genetic factors. By studying pedigrees, scientists can better understand how traits are passed down from one generation to the next and can make predictions about the likelihood of individuals inheriting certain traits.
7.
___ studied traits of pea plants and discovered the two fundamental laws of genetics.
Correct Answer
A. Mendel
Explanation
Mendel is the correct answer because he is known for his work on pea plants and is considered the father of modern genetics. Through his experiments, Mendel discovered the two fundamental laws of genetics - the law of segregation and the law of independent assortment. His findings laid the foundation for our understanding of inheritance and formed the basis of modern genetics.
8.
___ is a pattern of inheritance in which the gene for a trait is located on the X-chromosome, thereby creating disorders that are much more common in males than females.
Correct Answer
D. Sex-linked
Explanation
Sex-linked inheritance refers to the pattern of inheritance where the gene for a trait is located on the X-chromosome. This means that the trait is more commonly observed in males because they have only one X-chromosome, while females have two X-chromosomes. If a male inherits a recessive allele for a sex-linked disorder, he will express the disorder because he does not have another X-chromosome to mask the effects of the recessive allele. In contrast, females need to inherit two copies of the recessive allele to express the disorder. Therefore, sex-linked disorders are much more common in males than females.
9.
In humans, a ___ cell has ___ chromosomes.
Correct Answer
B. Haploid ... 23
Explanation
In humans, a haploid cell has 23 chromosomes. Haploid cells are cells that contain half the number of chromosomes compared to diploid cells. In humans, diploid cells have 46 chromosomes, while haploid cells have 23 chromosomes. This is because during sexual reproduction, haploid cells, such as sperm and egg cells, combine to form a diploid cell with the full complement of 46 chromosomes.
10.
A form of nuclear division that divides a diploid cell into haploid cells and produces gametes is known as ___.
Correct Answer
B. Meiosis
Explanation
Meiosis is a form of nuclear division that occurs in diploid cells and results in the production of haploid cells, specifically gametes. During meiosis, the chromosomes in the diploid cell are replicated and then divided twice, resulting in four haploid cells. This process is essential for sexual reproduction as it ensures that the offspring receive the correct number of chromosomes from each parent. Mitosis, on the other hand, is a form of nuclear division that results in the production of two genetically identical diploid cells. Cellular regeneration refers to the process of replacing damaged or lost cells, and binary fission is a form of reproduction in prokaryotic cells.
11.
A cell that has two copies of each chromosome is said to be ___.
Correct Answer
A. Diploid
Explanation
A cell that has two copies of each chromosome is said to be diploid. This means that the cell contains a complete set of chromosomes, with one copy inherited from each parent. In contrast, a haploid cell only has one copy of each chromosome, while a triploid cell has three copies. A gamete refers to a specialized haploid cell involved in sexual reproduction.
12.
A female gamete ___.
Correct Answer
B. Is called an ovum or an egg cell.
Explanation
The female gamete, also known as an ovum or an egg cell, is produced in the ovaries, not the testes. The testes produce male gametes called spermatocytes. A polar body is a small non-functional cell produced during oogenesis.
13.
Each set of three nucleotides on mRNA coding for an amino acid is referred to as a(n) ___.
Correct Answer
A. Codon
Explanation
A set of three nucleotides on mRNA that codes for a specific amino acid is called a codon. Codons are the basic units of the genetic code and determine the sequence of amino acids in a protein. Each codon corresponds to a specific amino acid or a stop signal. The correct answer is codon.
14.
Messenger RNA is formed in the process of ___.
Correct Answer
A. Transcription
Explanation
Messenger RNA is formed in the process of transcription. Transcription is the process in which the DNA sequence of a gene is copied into a complementary RNA molecule. This RNA molecule, known as messenger RNA (mRNA), carries the genetic information from the DNA to the ribosomes, where it is used as a template for protein synthesis during translation. Replication is the process of copying DNA, mutation refers to changes in the DNA sequence, and translation is the process of protein synthesis using mRNA.
15.
The process by which a DNA molecule is copied is ___.
Correct Answer
C. Replication
Explanation
The correct answer is replication. Replication is the process in which a DNA molecule is copied to produce an identical copy. During replication, the two strands of the DNA molecule separate, and each strand serves as a template for the synthesis of a new complementary strand. This results in two identical DNA molecules, each containing one original strand and one newly synthesized strand. Replication is a crucial step in cell division and ensures that each daughter cell receives a complete set of genetic information.
16.
Watson and Crick, with the help of Rosalind Franklin, were the first to suggest that DNA is ___.
Correct Answer
C. The shape of a double helix
Explanation
Watson and Crick, along with the assistance of Rosalind Franklin, proposed that DNA has the shape of a double helix. This means that DNA is structured as two strands that twist around each other in a spiral staircase-like formation. This groundbreaking discovery revolutionized our understanding of genetics and laid the foundation for further research in molecular biology.
17.
Which DNA sequence produced an mRNA strand with the sequence AGUACA?
Correct Answer
B. TCATGT
Explanation
The mRNA sequence is the complementary sequence to the DNA sequence. In this case, the DNA sequence that would produce an mRNA strand with the sequence AGUACA is TCATGT.
18.
Which of the following is a pair of complementary bases?
Correct Answer
B. Thymine and adenine
Explanation
Thymine and adenine are a pair of complementary bases because they form a base pair in DNA. In DNA, thymine always pairs with adenine through hydrogen bonding, forming a stable base pair. This pairing is essential for the structure and function of DNA, as it allows for the accurate replication and transcription of genetic information.
19.
There are literally hundreds of thousands of different organic molecules. Which statement best explains how this is possible?
Correct Answer
B. Carbon is unique in that it can make four chemical bonds.
Explanation
Carbon is unique in that it can make four chemical bonds. This allows carbon atoms to form stable covalent bonds with other carbon atoms and with other elements, creating a wide variety of organic molecules. Carbon's ability to form multiple bonds and create complex molecular structures is the basis for the vast diversity of organic compounds found in nature.
20.
Organic compounds always contain the element ____.
Correct Answer
A. Carbon
Explanation
Organic compounds are compounds that contain carbon atoms. Carbon is the key element in organic chemistry as it has the ability to form strong covalent bonds with other carbon atoms and a wide variety of other elements. This allows carbon to form the complex and diverse structures found in organic compounds, such as carbohydrates, proteins, lipids, and nucleic acids. Therefore, the correct answer is carbon.
21.
Which of the following is NOT a characteristic of RNA?
Correct Answer
B. It contains thymine.
Explanation
RNA contains uracil instead of thymine. Thymine is found in DNA, not RNA. RNA is a single-stranded molecule and it plays a crucial role in transferring genetic information from DNA to the ribosome for protein synthesis.
22.
Which of the following describes DNA?
Correct Answer
C. It controls the production of proteins.
Explanation
DNA, or deoxyribonucleic acid, is a molecule that contains the genetic instructions used in the development and functioning of all known living organisms. It is composed of nucleotides, which consist of a sugar (deoxyribose), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). DNA controls the production of proteins through the process of transcription and translation. Transcription involves the synthesis of messenger RNA (mRNA) from DNA, while translation converts the mRNA into proteins. Therefore, the statement "It controls the production of proteins" accurately describes DNA.
23.
The functional group -NH2 is called the ____.
Correct Answer
A. Amino group
Explanation
The functional group -NH2 is called the amino group. This group consists of a nitrogen atom bonded to two hydrogen atoms. It is commonly found in organic compounds, especially in amino acids, which are the building blocks of proteins. The amino group plays a crucial role in the formation of peptide bonds and the overall structure and function of proteins.
24.
Which of the following is a structural form of carbohydrate?
Correct Answer
A. Cellulose
Explanation
Cellulose is a structural form of carbohydrate because it is a complex polysaccharide made up of glucose molecules linked together. It forms the main structural component of plant cell walls and provides rigidity and strength to plant cells. Starch, on the other hand, is a storage form of carbohydrate, enzymes are proteins that catalyze chemical reactions, and RNA is a nucleic acid involved in protein synthesis. Therefore, cellulose is the correct answer as it specifically refers to a structural form of carbohydrate.
25.
Which of the following monomers make up a lipid?
Correct Answer
A. Glycerol and fatty acid
Explanation
Lipids are a diverse group of molecules that are insoluble in water but soluble in organic solvents. They are made up of two main components: glycerol and fatty acids. Glycerol is a three-carbon alcohol, while fatty acids are long hydrocarbon chains with a carboxyl group at one end. When glycerol combines with three fatty acids through dehydration synthesis, a triglyceride molecule is formed, which is a common type of lipid. Therefore, the correct answer is glycerol and fatty acid.
26.
Which of the following is NOT a nucleotide found in DNA?
Correct Answer
C. Uracil
Explanation
Uracil is not a nucleotide found in DNA. It is a nitrogenous base that is only found in RNA. DNA contains the nitrogenous bases adenine, cytosine, guanine, and thymine. Thymine pairs with adenine, while cytosine pairs with guanine in DNA. Uracil replaces thymine in RNA and pairs with adenine.
27.
Which of the following is a polymer of nucleotides?
Correct Answer
A. Nucleic Acid
Explanation
Nucleic Acid is the correct answer because it is a polymer of nucleotides. Nucleic acids are macromolecules made up of repeating units called nucleotides, which consist of a sugar molecule, a phosphate group, and a nitrogenous base. These nucleotides are linked together through phosphodiester bonds to form long chains, which are known as nucleic acids. DNA and RNA are examples of nucleic acids, and they play essential roles in storing and transmitting genetic information in living organisms.
28.
Which of the following is a polymer of amino acids?
Correct Answer
A. Protein
Explanation
Proteins are polymers of amino acids, as they are composed of long chains of amino acid monomers linked together by peptide bonds. These chains can fold and interact with each other to form complex three-dimensional structures, which determine their specific functions in the body. Carbohydrates, lipids, and nucleic acids are not polymers of amino acids, but rather have different molecular structures and functions.
29.
What is the main function of the Krebs cycle?
Correct Answer
C. Producing molecules that carry high-energy electrons to the electron transport chain
Explanation
The main function of the Krebs cycle is to produce molecules that carry high-energy electrons to the electron transport chain. The Krebs cycle, also known as the citric acid cycle, is a series of chemical reactions that occur in the mitochondria of cells. During the cycle, molecules such as NADH and FADH2 are produced, which carry high-energy electrons. These electrons are then transferred to the electron transport chain, where they are used to generate ATP, the energy currency of the cell.
30.
Which phrase best describes the electron transport chain in photosynthesis?
Correct Answer
C. A series of proteins located in the thylakoid membrane
Explanation
The electron transport chain in photosynthesis is a series of proteins located in the thylakoid membrane. This chain of proteins plays a crucial role in the light-dependent reactions of photosynthesis, where it transfers electrons from photosystem II to photosystem I, creating a proton gradient across the thylakoid membrane. This proton gradient is then used to generate ATP, which is essential for the synthesis of glucose in the Calvin cycle.
31.
The process by which plants use sunlight to make glucose is called ___.
Correct Answer
A. pHotosynthesis
Explanation
Photosynthesis is the correct answer because it is the process by which plants use sunlight to convert carbon dioxide and water into glucose and oxygen. It occurs in the chloroplasts of plant cells and is essential for the plant's survival. During photosynthesis, plants capture energy from sunlight and use it to produce glucose, which is a source of energy for the plant. This process also releases oxygen into the atmosphere, making it crucial for maintaining the balance of gases in the environment.
32.
Which of the following takes place in the light-dependent reactions of photosynthesis?
Correct Answer
B. Energy is captured.
Explanation
In the light-dependent reactions of photosynthesis, energy is captured from sunlight. This energy is used to convert ADP and NADP+ into ATP and NADPH, which are energy-rich molecules that are essential for the next stage of photosynthesis. This process occurs in the thylakoid membranes of the chloroplasts, where pigments like chlorophyll absorb light energy and transfer it to the electron transport chain. This chain then generates ATP through chemiosmosis, using the energy from the captured light. Therefore, "Energy is captured" is the correct answer as it accurately describes one of the key processes in the light-dependent reactions of photosynthesis.
33.
The main light-absorbing molecules found in plant leaves are called
Correct Answer
C. ChloropHyll
Explanation
Chlorophyll is the correct answer because it is the main light-absorbing pigment found in plant leaves. It is responsible for capturing sunlight energy during photosynthesis and converting it into chemical energy. Chlorophyll molecules are located within the chloroplasts, which are the organelles responsible for photosynthesis in plants. Thylakoids are the membranous structures within the chloroplasts where chlorophyll molecules are embedded. Grana are stacks of thylakoids. Therefore, while chloroplasts, thylakoids, and grana are all related to the process of photosynthesis, chlorophyll is specifically the light-absorbing molecule.
34.
Which of the following statements best describes the process of photosynthesis?
Correct Answer
D. Chloroplasts absorb sunlight and store chemical energy.
Explanation
Chloroplasts are the organelles in plant cells that contain chlorophyll, the pigment responsible for absorbing sunlight. During photosynthesis, chloroplasts absorb sunlight and convert it into chemical energy in the form of glucose, which is a type of simple sugar. This process allows plants to store energy that can be used for growth and other metabolic activities. Therefore, the statement "Chloroplasts absorb sunlight and store chemical energy" best describes the process of photosynthesis.
35.
What is the term for the jelly-like substance that is contained inside the cell membrane?
Correct Answer
A. Cytoplasm
Explanation
The jelly-like substance that is contained inside the cell membrane is called cytoplasm. It is a semi-fluid medium that fills the interior of the cell and surrounds the organelles. Cytoplasm plays a crucial role in various cellular processes, including the movement of organelles, transportation of molecules, and support for cellular structures. It also contains various enzymes and nutrients necessary for cellular metabolism and growth.
36.
Which of the following is a characteristic of S phase?
Correct Answer
D. DNA is replicated.
Explanation
The correct answer is DNA is replicated. During the S phase of the cell cycle, DNA replication takes place. This is a crucial step as it ensures that each daughter cell receives an identical copy of the genetic material. The other options mentioned, such as cell growth and normal function, cell growth and preparation for mitosis, and nuclear membrane reforms, are not specific to the S phase and can occur during other phases of the cell cycle as well.
37.
Which of the following is a characteristic of prophase?
Correct Answer
A. Nuclear membrane breaks down.
Explanation
During prophase, the nuclear membrane breaks down, allowing the chromosomes to become visible and move freely within the cell. This breakdown is necessary for the subsequent stages of mitosis, as it allows the chromosomes to align in the middle of the cell and be separated during anaphase. The breakdown of the nuclear membrane is a characteristic specific to prophase and is essential for the proper progression of cell division.
38.
What is the main function of the Golgi apparatus?
Correct Answer
C. Process and deliver proteins
Explanation
The main function of the Golgi apparatus is to process and deliver proteins. It receives proteins from the endoplasmic reticulum, modifies and sorts them, and then packages them into vesicles for transport to their final destination within the cell or for secretion outside the cell. This process involves adding carbohydrates and lipids to the proteins, which helps in their proper folding and stability. The Golgi apparatus plays a crucial role in maintaining the cell's protein homeostasis and ensuring that proteins are correctly targeted and delivered to their intended locations.
39.
Unlike a eukaryoteic cell, a prokaryotic cell does not have...
Correct Answer
B. A nucleus.
Explanation
A prokaryotic cell does not have a nucleus. This is because prokaryotic cells are simpler and lack a membrane-bound nucleus. Instead, their DNA is located in the cytoplasm, which is the gel-like substance that fills the cell. Prokaryotes have a nucleoid region where the DNA is concentrated, but it is not enclosed within a membrane. In contrast, eukaryotic cells have a true nucleus, which is a membrane-bound organelle that contains the DNA. The absence of a nucleus is one of the key characteristics that differentiate prokaryotic cells from eukaryotic cells.
40.
Which phrase best describes the effect of a catalyst on a chemical reaction?
Correct Answer
C. Decreases the activation energy
Explanation
A catalyst is a substance that increases the rate of a chemical reaction by lowering the activation energy required for the reaction to occur. By decreasing the activation energy, a catalyst provides an alternative reaction pathway with a lower energy barrier, allowing more reactant molecules to overcome the barrier and participate in the reaction. This results in an increased rate of reaction without being consumed in the process. Therefore, the phrase "decreases the activation energy" best describes the effect of a catalyst on a chemical reaction.
41.
Which of the following organelles can be found on the surface of the endoplasmic reticulum?
Correct Answer
C. Ribosomes
Explanation
Ribosomes can be found on the surface of the endoplasmic reticulum. This is because the endoplasmic reticulum is responsible for protein synthesis, and ribosomes are the cellular structures where proteins are synthesized. The endoplasmic reticulum provides a surface for ribosomes to attach and carry out protein synthesis. Therefore, ribosomes are the correct answer.
42.
Which organelle is the storehouse for most of a cell's genetic information?
Correct Answer
A. Nucleus
Explanation
The nucleus is the storehouse for most of a cell's genetic information. It contains the cell's DNA, which carries the instructions for the cell's functioning and development. The DNA is organized into structures called chromosomes, which are found within the nucleus. The nucleus also controls the cell's activities by regulating the expression of genes and directing the synthesis of proteins. Therefore, the nucleus is essential for the cell's genetic control and is responsible for storing and transmitting the genetic information to the next generation of cells.
43.
In the diagram to the right, what is structure B?
Correct Answer
B. Mitochondrial matrix
Explanation
The correct answer is mitochondrial matrix. In the diagram, structure B is labeled as the mitochondrial matrix. The mitochondrial matrix is the space enclosed by the inner membrane of the mitochondria. It contains enzymes that are involved in various metabolic reactions, including the citric acid cycle and fatty acid oxidation. The matrix also contains mitochondrial DNA and ribosomes, which are necessary for the synthesis of proteins within the mitochondria.
44.
In the diagram to the right, what is structure A?
Correct Answer
A. Folded inner membrane
Explanation
The correct answer is folded inner membrane. In the diagram, structure A is shown as a folded membrane within a larger membrane structure. This is characteristic of the inner membrane of a mitochondrion, which is highly folded to increase its surface area and accommodate various enzymes and proteins involved in cellular respiration. The mitochondrial matrix refers to the central compartment within the inner membrane, stroma is found in chloroplasts, and thylakoid membrane is a part of the chloroplast where photosynthesis occurs.
45.
The part of cellular respiration in which glucose is broken down is called
Correct Answer
D. Glycolysis.
Explanation
Glycolysis is the correct answer because it is the initial step in cellular respiration where glucose is broken down into two molecules of pyruvate. It occurs in the cytoplasm of the cell and does not require oxygen. Photosynthesis is the process by which plants convert sunlight into energy, while aerobic respiration and electron transport are subsequent steps in cellular respiration, occurring in the presence of oxygen.
46.
Where does glycolysis take place?
Correct Answer
A. Cytoplasm
Explanation
Glycolysis is the metabolic pathway that breaks down glucose to produce energy in the form of ATP. It takes place in the cytoplasm of the cell. This is where glucose is converted into smaller molecules like pyruvate through a series of enzymatic reactions. The cytoplasm is the fluid-filled region of the cell outside the nucleus, where most cellular processes occur. Therefore, glycolysis occurring in the cytoplasm is the correct answer.
47.
___ is known as the universal solvent.
Correct Answer
A. Water
Explanation
Water is known as the universal solvent because it has the ability to dissolve a wide variety of substances. This is due to its unique molecular structure, which allows it to form hydrogen bonds with other molecules. These hydrogen bonds break apart the solute molecules and surround them, dispersing them evenly throughout the water. As a result, water can dissolve many different types of compounds, making it an excellent solvent for various chemical reactions and biological processes.
48.
In the Linnaean system of classification, which of the following is most commonly defined as a group of organisms that can breed and produce offspring?
Correct Answer
B. Species
Explanation
In the Linnaean system of classification, a species is most commonly defined as a group of organisms that can breed and produce offspring. This is because species is the most specific and fundamental category in the Linnaean hierarchy, representing a group of organisms that share common characteristics and can interbreed to produce fertile offspring. The other options, such as phylum, genus, and order, are higher taxonomic ranks that encompass larger groups of organisms with broader characteristics and reproductive compatibility.
49.
Which kingdom is not included in domain Eukarya?
Correct Answer
A. Bacteria
Explanation
Bacteria is not included in domain Eukarya because it belongs to the domain Bacteria, which is a separate classification from Eukarya. Eukarya includes organisms that have a true nucleus and membrane-bound organelles, while bacteria are prokaryotic organisms that lack a true nucleus and membrane-bound organelles. Therefore, bacteria are not part of the Eukarya domain.
50.
How many kingdoms are in the current tree of life?
Correct Answer
C. Six
Explanation
The correct answer is six. This suggests that there are currently six kingdoms in the tree of life. The tree of life is a way to categorize and understand the diversity of life on Earth. It organizes organisms into different kingdoms based on their characteristics and evolutionary relationships. The six kingdoms typically recognized in the tree of life are Animalia, Plantae, Fungi, Protista, Archaea, and Bacteria. Each kingdom represents a distinct group of organisms with shared characteristics and evolutionary history.