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Science 3rd Quarter
Question | Answer |
---|---|
If a cell cannot move enough material through it's membrane to survive, then the ratio of its surface area to volume is | too small |
Before a cell can proceed to mitosis from the gap 2 stage of the cycle, it must | Pass a critical checkpoint |
During interphase a cell grows, duplicates organelles, and | Copies DNA |
Why do the cells lining the stomach divide more quickly then those in the liver? | They undergo more wear and tear |
During which of the following stages does the cytoplasm of a cell divide? | Mitosis |
Kinases and cyclins are internal factors that | Control the cell cycle |
Proteins from outside a cell that stimulate it to divide are called | Growth factors |
Which statement describes this chromosome | It is made up of two chromotids |
In a single celled organism, mitosis is used for | Reproduction |
Which of the following is true of malignant tumors? | They can cause tumors in other parts of the body |
One difference between a cancer cell and a normal cell is that | Cancer cells divide uncontrollably |
Which statement about the process of binary fission is true? | It does not take place in multicellular organisms |
A plant's leaf consists of | Various types of tissue |
Cells in a developing embryo | Their location in the embryo |
Which organism is capable of reproduction through asexual mitosis? | Starfish |
Which sequence shows the progression from least complex structure to most complex structure? | Cell-tissue-organ-organ system |
Which phrase best describes an organ system? | Group of organs that work together |
Which of the following is a direct result of a normal cell's ability to express only certain genes? | Cells can differentiate and specialize |
Stem cells are important to multicellular organisms because of their | Capacity to differentiate |
Which type of stem cell can grow into any other cell type? | Totipotent |
The most common form of reproduction among prokaryotes is | Binary fission |
What is the main difference between binary fission and mitosis? | There is no DNA replication in binary fission |
Which of the following statements is true of asexual reproduction? | It produces generally identical offspring |
Starfish that reproduce by splitting into pieces are reproducing by | Fragmentation |
Vegetative reproduction, budding, and fragmentation are examples of | Reproduction through binary fission |
In which stage of the cell cycle do the nucleus and its contents divide? | Mitosis |
During the gap 1 stage of the new cell cycle, a cell | Carries out its normal functions |
Which of the following phrases best describes cytokinesis? | Division of the cytoplasm |
Which statement is true about the rates of cell division in eukaryotes? | They vary greatly within an organism |
Which of the following limits the maximum size of a cell? | The ratio of cell surface area to volume |
The processes of mitosis and cytokinesis produce two identical | daughter cells |
The process of organizing and condensing DNA into its compact form takes place at the start of | Interphase |
Which is the term for the group of proteins that organized and condenses long strands of DNA into tight coils? | telomeres |
During which phase of mitosis to sister chromatids seperate from each other? | anaphase |
Which of the following statements is true of cytokinesis? | completes the cell cycle |
Proteins that bind to cells and stimulate cell division are called | growth factors |
What is the term for the programmed death of cells? | apoptosis |
Two internal factors that are important in advancing the cell cycle are | Phosphates and enzymes |
Which phrase best describes cancer? | Uncontrolled cell growth |
Substances known to produce or promote cancer are called | carcinogens |
Two similar chromosomes that you inherit from your parents are called | homologous chromosomes |
Meiosis produces cells with how many chromosomes? | 23 |
Which of the following cell types is diploid? | Somatic cell |
A distinguishing characteristic that can be inherited is a | trait |
Which of the following phrases describes the punnet square in figure 6.1? | monohybrid heterozygous-heterozygous cross |
Which of the following statements is true of a homozygous alleles? | They are identical forms of the same gene. |
Which law states that organisms inherit two copies of each gene and donate one copy to each of their offspring? | Law of segregation |
Mendel knew that the variations in the offspring generations resulted from his experiments because he | controlled the fertilization process. |
Which pair of genes in figure 6.2 would be most likely to be inherited together? | A and B |
Which event takes place during anaphase II of meiosis II? | Sister chromatids seperate |
Recessive alleles may not be expressed because they are | Masked by a dominant allele |
Mendel's second law of genetics, the law of independent assortment, is one explanation of the | Genetic variation within species. |
Which of the following events is an important factor in increasing variety among sexually reproducing organisms? | crossing over |
Mendel's observation that traits are inherited seperately was based on which set of experiments? | dihybrid cross |
Imagine two heterozygous parents. Each has a dominant allele X for brown eyes and a recessive allele x for blue eyes. The phenotypic ration for brown:blue eyes in their children is | 3:1 |
A kidney cell is an example of which type of cell? | somatic cell |
How many chromosomes are in a human gamete? | 23 |
Which of the following best describe the genetic material a person recieves from his or her father? | 22 autosomes and an X or Y chromosome. |
Which phrase best describes the process of meiosis? | Produces haploid genetics |
At fertilization, what happens to the sex cells? | Their nuclei fuse to form one nucleus |
Which of the following statements is true of homologous chromosomes? | They contain the same genes |
Which phrase best describes meiosis I? | Division of homologous chromosomes |
What happens to sister chromatids in meiosis II? | They are divided |
Gametogenesis is the term for | The production of gametes |
What does an egg contribute to the embryo that a sperm does not contribute? | organelles |
Which of the following is an example of a biological trait? | eye color |
Mendel began his experiments with purebred pea plants. This approach enabled him to determine that variations among offspring were the result of | his crossings |
When Mendel crossed plants that were purebred purple-flowered with plants that were purebred white-flowered, the resulting offspring all had purple flowers. When allowed to self-pollinate, this F1 generation gave rise to white-flowered plants as well as p | pt 1 |
as purple. As a result, Mendel determined that individual traits are | Inherited as dicrete units. |
Mendel was able to identify predictable patterns of heredity. He succeeded mainly because he chose to study traits that | only had two forms. |
Which phrase best describes the term genome? | The genes that make up an organism |
Hair color and eye color are examples of a person's | phenotype |
When an organism has two alleles at a particular locus that are different, the organism is called | heterozygous |
If a pea plant were homozygous recessive for height, how would its alleles be represented? | tt |
An allele is dominant in a heterozygote when it is | expressed and the other allele is not |
What do the letters inside the grid of a Punnet square represnet? | genotypes of offspring |
What is the possibility that the offspring of a cross between a homozygous recessive parent and a heterozygous parent will be homozygous recessive? | 1/2 |
The term for a cross that involves just one trait, such as pod shape, is called a | monohybrid cross |
What is the phenotypic ratio of a monohybrid cross between two heterozygous parents? | 3:1 |
Which of the following observations did Mendel make as a result of his experiments with dihybrid crosses? | Different traits are inherited seperately |
About how many different contributions of chromosomes can be produced through the random fertilization of human gametes? | 2^23x2^23 |
Which phrase best describes the process of crossing over? | Pairs of homologous chromosomes exchange segments. |
Suppose a gene that codes for flower color is linked with a gene that codes for leaf shape. Which statement is true of this pair of genes? | They are close together on the same chromosome. |
During what stage of meiosis does crossing over occur? | Prophase I of meiosis I |
Which of the following is a result of the study of gene linkage? | The relative distances between genes can be calculated. |
A person who has a disorder caused by a recessive allele is | Homozygous for a recessive allele |
Gene expression is influenced by many factors. Which of the following is a factor in gene expression? | Environment |
The Punnet square in figure 7.1 shows a cross between two parents who have the genotype Ss for a genetic disorder caused by a recessive allele. Which of the following will have the genetic disorder? | ss offspring |
Two parents have the genotype Gg for a genetic disorder caused by a dominant allele. What is the chance that any of their children will inherit the disorder? | 75% |
For an XX female to express a recessive sex-linked trait, she must have | two recessive alleles. |
Human height occurs in a continuous range because it is affected by the interaction of several genes, making it a | polygenic trait |
Suppose a mouse is homozygous for alleles that produce black fur and homozygous for alleles of an epistatic gene that prevents fur coloration. What color will the mouse have? | All white |
A female is born with attached earlobes which is a recessive phenotype. Which of the following genotypes could her parents have? | Rr and rr |
Some members of a family have a recessive sex-linked disorder. Which of the following statements about the family would be true? | Only females would be carriers |
What is the main reason that sex-linked disorders are most often observed in males? | The Y chromosome cannot mask alleles on the X chromosome. |
Most of the traits expressed in a person's phenotype are determined by | autosomal genes |
Which of the following phrases is true of X chromosome inactivation? | occurs in cells of female mammals |
A person who is heterozygous for a disorder caused by recessive alleles is a carrier of the disorder. A carrier is a person who | Does not have the disorder but can pass it to the offspring |
Genes that are located on sex chromosomes are called | sex linked |
Which statement is true of a sex-linked recessive gene? | In an XY male, this recessive gene is always expressed. |
Much of what we know about single-gene traits in humans is the result of studying | genetic disorders |
What is the main difference between the carrier of a sex-linked disorder and the carrier of an autosomal disorder? | The carrier of a sex-linked disorder is always female but does not have the disorder |
A chart that traces the phenotypes and genotypes within a family is called a | pedigree |
A genetic disorder is traced within a family. The disorder occurs mostly in males. The gene for this disorder is most likey | on the X chromosome |
Which of the following types of genetic information can be identified easily with a karyotype? | homologous chromosomes |
Unlike the traits studied by Mendel, most traits are produced by genes with | multiple alleles |
A plant that is homozygous for red flowers is crossed with a plant that is homozygous for white flowers. In the case of incomplete dominance, the flowers of the offspring will be | pink only |
In the case of codominant alleles, a plant that is homozygous for red flowers that is crossed with a plant that is homozygous for white flowers will produce flowers that are | red and white spotted |
Identical twins who are raised apart can have differences that last a lifetime. This is evidence that | environment and genotype interact to affect phenotype |
Which scientist used chemical analysis to show that the genetic material in bacteria is DNA? | Oswald Avery |
How did Hershey and Chase's use of radiolabeled bacteriophages to study the genetic material validate Avery's research? | It demonstrated conclusively that the genetic material is not protein |
The DNA double helix model used today is the product of research done by the scientists | Watson and Crick |
Suppose you can read the sequence of bases on only one strand of the double helix. What would you use to figure out the sequence on the other strand? | base pairing rules |
Which of the following is the site of the DNA replication in eukaryotes? | nucleus |
What does the DNA polymerase do during replication? | Binds nucleotides together and corrects base pair errors |
What message does mRNA carry? | The genetic code that, when translated, forms proteins |
When does replication occur? | Once in every cell cycle |
Crick's central dogma of molecular biology is essentially a summary of | replication, transcription, and translation |
How many amino acids are in the following sequence of mRNA nucleotides? CGAUACAGUAGC | 4 |
When does mRNA processing take place? | after transcription |
The nucleotide sequences that are removed during mRNA processing are called | introns |
The LAC operon is an example of how gene regulation occurs in | bacteria |
Generally, mutations that affect a single gene occur during | replication |
Cystic fybrosis is an example of a genetic disease caused by the deletion of a nucleotide. What is the term for this type of mutation? | frameshift |
What is the term for the nucleotide sequences that are removed during mRNA | introns |
In prokaryotes, gene expression is regulated by controlling | transcription |
What is the main function of a promoter? | Tells RNA polymerase where to start |
What is the term for three-nucleotide sequence that codes for an amino acid? | codon |
How many amino acids are used to make up all of the proteins in the human body? | 20 |
A tRNA that carries the amino acid methionine pairs with which type of codon? | start codon |
Which phrase best describes translation? | Converts mRNA into a polypeptide |
Which of the following is the site of translation? | ribosome |
The central dogma of molecular biology states that information flows in one direction from | DNA to RNA to proteins |
Choose the nucleotide sequences of the RNA strand that would be complementary to the following DNA strand: GTAGTCA | CAUCAGU |
The main function of tRNA is to | Bring amino acids from the cytoplasm to the ribosomes |
Which of the following events occur directly after RNA polymerase recognizes the transcription start site of a gene? | The DNA strand begins to unwind, seperating the two strands |
A primary difference between transcription and replication is that transcription | Happens repeatedly throughout a single cell cycle |
The process that makes an exact copy of a cell's DNA is called | replication |
What are the main function of DNA polymerase? | Binds nucleotides and corrects base pair errors |
Which of the following events occurs directly after a DNA molecule is unzipped? | Free-floating nucleotides pair up with exposed bases |
The process of making new DNA molecules is semiconservative. This means that every new DNA molecule is composed of | one original and one new strand of DN |
When new DNA molecules are formed, almost all errors are detected and fixed by | DNA polymerase |
The four types of nucleotides that make up DNA are named for their | nitrogen-containing bases |
Erwin Chargaff concluded what about the four bases? | A=T and C=G |
Which of the following DNA sequences in complementary to the base sequence ACCGTAT? | TGGCATA |
Combining the work of other scientists with their own research, Watson and Crick discovered that two strands of DNA join together to form a | double helix |
What holds base pairs together? | Hydrogen bonds. |