WE will review genetics and gene flow
DNA: DEOXYRIBONUCLEIC ACID
Ch. 7, pg. 122
DNA: is the molecule of heredity, common to all life forms, that is passed from parents to offspring.
Gene Transcription and translation
Messenger RNA (mRNA): RNA copy of an original DNA sequence made during transcription
Transcription: the first stage of gene expression, during which cells produce molecules of messenger RNA (mRNA) from the instruction encoded within genes
Translation: the second stage of gene expression. Translation 'reads' mRNA sequences and assembles the corresponding amino acids to make proteins.
RNA Polymerase: the enzyme that accomplishes transcription. RNA polymerase copies a strand of DNA into a complementary strand or RNA,
Ribosome: the cellular machinery that assembles protens during the process of translation.
Codon: a sequence of three mRNA nucleotides that specifies a particular amino acid
A type of cell division that results in two cells, each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.
Gene: A sequence of DNA that contains the information to make at least one protein
Gene Expression: The process of using DNA instructions to make proteins.
Genotype: Genetic makeup of an organism
Phenotype: the physical qualities of an organism including observable or not observable traits
Meiosis contributes to genetic variation due to which of the following characteristics of the process?
A. The process begins with one diploid cell containing two copies of each chromosome.
B. Gametes that contain half the genetic information are formed.
C. Homologous chromosomes move to opposite sides of the cell to form new nuclei.
D. When homologous chromosomes split, sections of chromosomes can switch places.
The gene for tallness (T) in a pea plant is dominant over the gene for shortness (t). In a cross between two heterozygous parent pea plants, we can predict that what percentage of the offspring will be tall?
Which of the following provides evidence for the idea that certain environmental factors can alter DNA and cause mutations?
A. The processes responsible for cellular growth and repair are more efficient when an individual receives adequate nutrition.
B. Characteristics of certain individuals within a population make them more or less likely to survive an environmental change.
C. Skin cancer is more likely to develop in individuals who experience excessive exposure to sunlight.
D. Errors that occur during mitosis can sometimes provide a benefit to the individual but are more likely neutral.
An investigation involves a species of microorganisms. One population is exposed to radiation and the other population is shielded from radiation. The population exposed to radiation exhibits a mutation while the other population exhibits no mutation.
Both populations are then allowed to reproduce under normal conditions. Thirty generations later, the descendants of the population exposed to radiation still exhibit the mutation. Why can’t this observation be used to support the claim that the exposure to radiation did not cause the mutation?
A. Only mutations that are beneficial are passed on to successive generations.
B. Neither population had the mutation before exposure to radiation.
C. Once a mutation is present in the genome, it is inherited by offspring.
D. Some mutations are the result of errors in the transcribing of genes.
The ability for people to roll their tongue is dominant to people who cannot. If a tongue roller and a non-tongue roller were crossed, the highest percentage of potential non-tongue roller offspring would be which of the following?
The mechanism of natural selection works, primarily, to change which of the following?
A. The genotypes of individual organisms and their expression
B. The rate of mutations resulting from external factors
C. The distribution of traits in a population over time
D. The likelihood that traits of organisms are passed on
The frequency of a certain trait in a population will increase over many generations if which of the following is true?
A. The trait is carried by all members of the population, but expressed only in a few.
B. Those organisms with the trait have better reproductive success than those without it.
C. Those organisms without the trait interbreed freely with those that have the trait.
D. There is a sudden change to the environment that reduces the population with the trait.
For evolution to function, all of the following characteristics of genes are necessary EXCEPT–
A. there is variation in genes in a population.
B. genetic traits are inheritable across generations.
C. genetic information is stored on chromosomes.
D. genes result in traits that provide advantages.
The peppered moth, Biston betularia, has two forms. A white-bodied form and a dark-bodied form. The table provided shows the percentage of each type of the peppered moth in a population over several years.
This evidence can best be used to support which of the following conclusions?
A. A new predator of the peppered moth was introduced between 1965 and 1985.
B. The trait for a white-body became more advantageous between 1965 and 1985.
C. Dark-bodied moths obtained more resources between 1965 and 1985.
D. The habitat requirements of dark-bodied moths changed between 1965 and 1985.
The claim that a certain species of plants produce ammonia in their roots to counteract the negative effects of acidic soil would be supported by which of the following observations?
A. The frequency in the population of individual plants that produce high levels of ammonia in their roots increases with soil acidity.
B. As the acidity of the soil increases, the number of individual plants able to survive and reproduce decreases.
C. When the plants are grown in soil with a neutral pH, the levels of ammonia in the roots of the plants remains stable over generations.
D. When plants that produce high levels of ammonia are crossed with plants that produce low levels, the offspring survive.
Natural selection occurs when which of the following conditions are met?
A. Individual organisms depend on each other to obtain available resources
B. Variations between individual organisms lead to differential survival chances
C. Habitat and nutrient resources in an area are plentiful over a long period of time
D. The conditions in an ecosystem support a wide range of living organisms
The flightless cormorant of the Galapagos Islands is the only cormorant bird which has lost its ability to fly. What is the most likely reason for this?
A. This species existed for a long period of time in an environment with no natural predators and ample food on the ground
B. There are no trees on the island where this species lives
C. All members of this species which could fly left the island
D. Birds which live near the ocean do not need to fly
The image provided shows two distribution curves. Each graph shows the number of individuals with a certain body length. The graphs compare an original generation (Generation 1) to their descendants (Generation 100).
These graphs provide support for which of the following claims?
A. By Generation 100, no individuals with a body length below 30 cm were able to reproduce
B. The optimal body length selected for, by Generation 100, is approximately 45 cm
C. Environmental pressures over the generations selected for a body length increase of 10 cm
D. These organisms are unable to achieve a body length greater than about 50 cm
Invasive species of asian carp introduced to the Mississippi River have thrived and are threatening to eliminate many native species of fish. Which of these could be a contributing reason why?
A. These species of fish lay many more eggs than the native species
B. These species of fish eat a greater variety of foods than native fish, destroying entire ecosystems
C. These species can survive in more extreme temperatures and water with a lower oxygen concentration
D. All of these can be contributing reasons
The graph shows the number of individuals in a population with a certain phenotype in a starting population (Generation 1) and at a later time (Generation 50).
This graph best represents which of the following combinations of phenotype and selective pressure?
A. Phenotype represents neck length of animals that feed on leaves growing at greater heights
B. Phenotype represents thickness of fat layers in mammals living in region getting colder
C. Phenotype represents body mass of insects where predators prefer larger insects
D. Phenotype represents bone density for birds that live and feed underwater
The provided chart compares base sequences of homologous segments of DNA from four different primates. The information in the chart can be used to support which of the following claims?
A. The baboon is more closely related to the lemur than to the chimpanzee.
B. The gorilla is more closely related to the chimpanzee than to the baboon.
C. The lemur is more closely related to the chimpanzee than to the baboon.
D. The chimpanzee is more closely related to the lemur than to the gorilla.
Comparing the bones pictured in this diagram can provide evidence to support which of the following conclusions?
A. The humerus bone evolved separately in many different lines of animals.
B. The size and position of various bones indicates how highly evolved an animal is.
C. Fossil evidence of bones provides the strongest evidence for evolution.
D. Humans, lions, and birds evolved from a common ancestor.
The diagram provided shows a breakdown of the genomes of humans, mice, chickens and zebrafish. The numbers in overlapping regions indicate orthologous sequences, similar genes which indicate shared ancestry. The data in the diagram best supports which of the following conclusions?
A. There are no gene sequences that are common to all these animals.
B. The common ancestor of the mouse and the chicken lived very recently.
C. The mouse and the zebrafish share the closest relationship of all animals shown.
D. Humans are more closely related to zebrafish than to chickens.
Studying which of the following would provide the best evidence that two organisms share a common ancestor?
A. Amino acid sequence
B. Dietary preferences
C. Habitat requirements
D. Social group interactions
Studying the embryology of animals provides important evidence to support claims of shared evolutionary history. What feature of embryology makes it capable of providing data for common evolutionary history not readily available from other sources?
A. As the embryo develops, it reveals the expression of genes.
B. The growth of the embryo is achieved by differentiation of cells.
C. A developing embryo exhibits structures not present in the adult animal.
D. The development of embryos of a certain species is consistent.
Which of the following best explains why different cells within an individual organism function differently?
A. The functions of cells are determined by the chemical messengers sent to them.
B. The function of individual cells depends on the cell’s location in the body.
C. Proteins regulate which genes within a cell are activated and which are not.
D. Each type of cell within an organism contains unique genetic information.
In humans, the CFTR gene is responsible for a protein that regulates the components of sweat, digestive fluids, and mucus. Individuals with a mutated version of this gene develop cystic fibrosis. Which of the following research questions would provide the best data for clarifying the role of DNA in the development of this disease?
A. What environmental factors stimulate or slow the production of sweat, digestive fluids, and mucus?
B. What is the current rate of the development of cystic fibrosis in the human population and has this changed over time?
C. Is cystic fibrosis present in individuals who have a normal, non-mutated copy of the CFTR gene?
D. Are the components of sweat, digestive fluids, and mucus significantly different in individuals with cystic fibrosis?
Which of the following best describes the structural relationship between genes, chromosomes, and DNA?
A. Genes consists of two long strands of chromosomes, and each of these two strands consists of molecules called DNA.
B. Each DNA molecule consists of a number of pairs of genes, and each pair of genes on the DNA molecule is made up of chromosomes.
C. Each chromosome consists of a number of DNA molecules, and each DNA molecule is made up of one to four different genes.
D. Each chromosome consists of a single long DNA molecule, and each gene on the chromosome is a particular segment of that DNA.
The function of chromosomes can best be described as -
A. producing energy through metabolism.
B. transmitting electrical signals through the body.
C. controlling the rate of cellular division.
D. regulating the production of specific proteins.