Bio Final
According to the diagrams, what was a short term carbon bank, and what was a long term carbon bank that stored carbon when it was not in the atmosphere? A) plants and animals; fossil fuels B) fossil fuels; plants and animals C) the ocean acted as both D) plants and animals; volcanoes E) all of the above
A
Elaborate courtship behaviors in animals, such as the blue-footed booby of the Galápagos islands, is an example of which of the following reproductive barriers? A) behavioral isolation B) mechanical isolation C) temporal isolation D) postzygotic isolation E) hybrid sterility
A
Eukaryotic cells have DNA enclosed in a double membrane called the nucleus. The nucleus functions to A) separate the DNA from other activities that occur in the cytoplasm. B) prevent the DNA from influencing the activities in the cytoplasm. C) prevent materials associated with the DNA from coming into contact with the cell's cytoplasm. D) separate the DNA and mRNA from the cytoplasm. E) separate the DNA from the RNA.
A
If the parental genotype is EeWw what are the potential allele combinations that could occur at the end of Meiosis? A) EW, Ew, eW, and ew B) EW, EE, eW, and ww C) WW, Ew, EW, and ew D) EE, WW, ee, and ww E) EW, Ew, ee and ww
A
In the equation CO2 + H2O yields H2CO3 the H2CO3 is carbonic acid. If atmospheric CO2 levels increase, what effect would this have on the ocean? A) As CO2 increases, there would be no net change in H2CO3, (it would stay the same). B) As CO2 increases, the oceans would become more basic. C) As CO2 increases, the oceans would not change because they are too big. D) As CO2 increases, the oceans would become more acid. E) None of the above.
A
Mitochondria & chloroplasts are similar in that they both ________; but are different in that mitochondria, but not chloroplasts, ______________. A) are involved in energy conversions; are found in nearly all eukaryotic cells B) are found in bacteria; are used to capture radiant energy and convert it into chemical energy C) are organelles involved in the production of proteins; are found in animal cells D) produce glucose needed for cellular processes; are found in plant cells E) are responsible for cell movements; help to produce the microtubules seen in cilia
A
Plant cells and animal cells differ in cytokinesis because A) plant cells need to build a cell wall while animal cells do not. B) plant cells need to build a cell wall while animal cells built the extra cellular matrix. C) animal cells need to build a cell membrane while plant cells do not. D) animal cells are living while plant cells are not. E) plant cells divide by mitosis while animal cells divide by meiosis.
A
Sickle cell anemia is caused by a recessive genetic disorder. Individuals who are homozygous recessive (ss) usually die before 2 years of age without medical treatment. However, a single copy of the "s" form of the gene conveys tremendous resistance to the disease malaria without tremendous negative side effect. Homozygous dominant individuals (SS) are easily infected by malaria. Malaria is often times fatal. A population of humans living in a malaria-infested environment has 88% of the children born who are phenotypically normal. Use these two equations to solve the following. p + q = 1 and p2 + 2pq + q2 = 1 What is the frequency of the homozygous recessive individuals in this population? A) 0.120 B) 0.346 C) 0.453 D) 0.654 E 0.880
A
The molecule cytochrome c supports the theory of evolution as biochemical evidence. Which of the following is not part of that evidence? A) Cytochrome c has evolved multiple times among many species. B) Cytochrome c has the same function in all organisms. C) The genetic code for cytochrome c differs among species. D) Cytochrome c is found in a variety of organisms from yeast to humans. E) Cytochrome c plays a role critical to survival.
A
The second law of thermodynamics states that all energy transformations result in more disordered energy. How do living organisms, which depend on chemical potential converting to kinetic energy to fuel their function, continue to live? A) they must constantly take in chemical potential energy for fuel and excrete waste B) living things do not obey the laws of thermodynamics C) they must constantly take in chemical potential energy for fuel D) they excrete the disordered molecules and lose the disordered energy as heat E) they take the disordered molecules and heat energy and use them to create new fuel
A
What happens when an individual is produced that possesses a trait far away from the mean value? A) That extreme individual will likely not survive and reproduce. B) That extreme individual will be more likely to survive and reproduce. C) That extreme individual will have neither an advantage nor a disadvantage than other individuals. D) All phenotypes have equal likelihood of surviving and reproducing. E) The average phenotype is less likely to survive and reproduce.
A
What is Biology,and what may it encompass? A) The study of living organisms, divided into many subfields that may include cells and their sub-cellular components. B) The study of living organisms, divided into many subfields that may include physiology, examining the cells, tissues, and organs of individuals. C) The study of living organisms, divided into many subfields that may include heredity, and how organisms inherit and/or pass on the traits and characteristics they posses. D The study of living organisms, divided into many subfields that may include the interactions of organisms as a population within their environment, and the influence(s) that environment plays on those organisms E) All of the above.
A
Which of the following organelles would be abundant in a sperm cell that is seeking to fertilize an egg cell? A) mitochondria B) lysosomes C) smooth endoplasmic reticulum D) Golgi apparatus E) ribosomes
A
Which of the following statements reflects what occurs in the flow of energy conversions through living systems? A) Chloroplasts convert solar energy to the chemical energy of nutrient molecules. B) Mitochondria convert ATP molecules into glucose. C) Chloroplasts produce CO2 and H2O during photosynthesis. D) Mitochondria capture solar energy and convert it to oxygen. E) Chloroplasts burn glucose into ATP molecules during cell respiration.
A
Which of the following would be considered a separate species as defined by the biological species concept? A) the red maple and the sugar maple, which are found throughout large parts of North America, but rarely hybridize B) two populations of fox squirrels, one that lives on a hillside, and one that lives in the river valley C) two populations of North American orioles, one that lives on the east coast, and one that lives on the west coast D) separate populations of bobcats, one that lives on a rocky slope, and one that lives in an upland forest several miles distant E) the Chihuahua and the Siberian husky, two different breeds of dog
A
A male is always homozygous for a trait that is A) codominant. B) X-linked. C) autosomal. D) dominant. E) dihybrid.
B
A proto-oncogene differs from a tumor suppressor gene because a proto-oncogene A) may cause cancer if mutated, whereas a tumor suppressor gene cannot. B) stimulates mitosis in a normal cell, whereas a tumor suppressor gene inhibits mitosis. C) only activates enzymes in a cell that allow metastasis. D) inhibits the cell cycle, whereas a tumor suppressor accelerates the cell cycle. E) promotes meiosis, whereas a tumor suppressor gene promotes mitosis.
B
A zygote fails to undergo mitosis because of a mismatched numbers of chromosomes. This is an example of A) hybrid sterility. B) zygote mortality. C) prezygotic isolation. D) temporal isolation. E) allopatric speciation.
B
After spending an hour working outside in the hot, sunny weather, a person typically perspires and will need to drink water. This is part of A) metabolizing energy. B) maintaining homeostasis. C) regulating blood proteins. D) capturing solar energy. E) adaptation to the warm weather.
B
DNA replication is called semiconservative because A) one of the two resulting DNA molecules is new. B) the two resulting DNA molecules each have one new DNA strand and one old strand from the original DNA molecule. C) both of the resulting DNA molecules are composed of new strands of nucleotides. D) no extra nucleotides are incorporated into the replicated DNA molecules. E) the sequence of nucleotides in one strand is conserved, whereas the new DNA molecule consists of a unique sequence of nucleotides
B
DNA replication makes a(n) ____ copy of the DNA strand, while transcription makes a(n) ____ copy of the DNA strand. A) mRNA; DNA B) DNA; mRNA C) DNA; tRNA D) mRNA; tRNA E) mRNA; rRNA
B
Fitness refers to A) the variation in traits within the population. B) reproductive success. C) mutations that benefit an organism's survival. D) the physical health of an individual. E) the physical health of a population.
B
If a finch population with heritable, variable beak size and shape arrived on an island on which only large seeds were available as a source of food, describe the natural selection process that would follow. A) Finches with smaller beaks would grow larger beaks so that they could eat the large seeds. All birds will reproduce and the frequency of large beaks within the population will increase. B) Finches with larger beaks will more easily eat the large seeds and thus more likely survive and produce offspring with similarly large beaks. The frequency of large beaks within the population will increase. C) All of the finches with small and medium beaks will soon die; all of the finches with large beaks will survive. The frequency of large beaks within the population will increase. D) Finches with smaller beaks would grow larger beaks so that they could eat the large seeds. Only these birds that grew larger beaks will reproduce and the frequency of large beaks within the population will increase. E) Finches with larger beaks will more easily eat the large seeds and not need to reproduce.
B
In what function do the embedded membrane proteins at "c" serve? A) simple diffusion B) facilitated and active transport C) support for the membrane D) phagocytosis E) osmosis
B
One species forming multiple new species is called A) natural selection. B) speciation. C) adaptation. D) biogeography. E) artificial selection.
B
Sickle cell anemia is caused by a recessive genetic disorder. Individuals who are homozygous recessive (ss) usually die before 2 years of age without medical treatment. However, a single copy of the "s" form of the gene conveys tremendous resistance to the disease malaria without tremendous negative side effect. Homozygous dominant individuals (SS) are easily infected by malaria. Malaria is often times fatal. A population of humans living in a malaria-infested environment has 88% of the children born who are phenotypically normal. Use these two equations to solve the following question. p + q = 1 and p2 + 2pq + q2 = 1 What is the frequency of the homozygous dominant individuals? A) 0.346 B) 0.428 C) 0.654 D) 0.880 E) 1
B
Sickle cell anemia is caused by a recessive genetic disorder. Individuals who are homozygous recessive (ss) usually die before 2 years of age without medical treatment. However, a single copy of the "s" form of the gene conveys tremendous resistance to the disease malaria without tremendous negative side effect. Homozygous dominant individuals (SS) are easily infected by malaria. Malaria is often times fatal. A population of humans living in a malaria-infested environment has 88% of the children born who are phenotypically normal. Use these two equations to solve the following questions. p + q = 1 and p2 + 2pq + q2 = 1 What is the frequency of the recessive allele in this population? A) 0.120 B) 0.346 C) 0.453 D) 0.654 E) 0.880
B
Tanning booths and other sources of high amounts of ultraviolet radiation cause something called a "Thymine Dimer", where two adjacent T's in your DNA stop binding complementarily to the A's across from them, and start binding to each other, like shown in the image to the right. This causes a "kink" in the normally double-stranded DNA. Your normal cellular machinery "proofreads" your DNA as part of mitosis, and will "see" this "kink" and try to remove it by cutting out what it sees as an extra A across from the kink, or an extra T in the kink itself. Which of the following mutations does this seem most like? A) Insertion B) Deletion C) Substitution D) Silent E) This doesn't happen, tanning booths are perfectly safe!
B
The filled-in squares of a Punnett square represent A) the numbers of individuals with each version of a trait. B) all possible combinations of gametes based on a cross between the two parents. C) an exact ratio that must always occur when the same parents have 4 offspring. D) examples of some of the offspring that can arise from a one-trait cross. E) the gametes from one parent.
B
The purpose of a control group in an experiment is A) to prove the hypothesis. B) for comparison to the other test groups. C) for comparison to the results of other experiments. D) to prove the prediction. E) to control the dependent variable.
B
The sugar glider in Australia and the flying squirrel in North America are both small mammals with large expanses of loose skin between their fore- and hind-limbs allowing them to glide from tree to tree within their respective forest habitats. These two species are distantly related but are very similar in their overall appearance. Darwin's explanation for their similarity is that A) both are descendants from a recent common ancestor. B) each have adapted in very similar ways to similar habitats. C) the similarity of the two unrelated species is simply coincidence. D) the two species were created to have similarities. E) the two species must be related to possess such like qualities.
B
Which of the following is an example of an ecosystem? A) zebras and the lions that prey on them B) a coral reef together with all the fishes and invertebrates living in and around it C) flowering plants and all the insects and birds that pollinate them D) male prairie chickens competing for access to mates E) rabbits eating carrots
B
Which of the following is true about the majority of LDCs? A) They consume the most fossil fuels. B) They support the highest populations. C) They produce the most hazardous wastes. D) They have the largest environmental impact. E) They exhibit the highest per capita resource consumption.
B
Which of the following lists is in the correct order, from the least inclusive to the most inclusive? A) allele - gene - chromosome B) gene - allele - chromosome C) allele - chromosome - gene D) chromosome - gene - allele E) gene - chromosome - allele
B
A recent report by the CDC (Center for Disease Control and Prevention) has stated that tanning booths are now responsible for more cancer than cigarettes (if you picked E above I hope you reconsider!). Based on this, which of the following makes the most sense? A) Just like smoking, as long as you only do it in small doses it should be okay. B) Your body should be able to build up a tolerance, so start with small doses, and build up from there. C) Just like smoking, any exposure would increase your risk of cancer, so it is best to avoid altogether. D) Science is just a bunch of guessing! Let's hand out cigarettes AND tanning passes to kids to get them started young so they can build up immunity to both! E) More than one of the above.
C
All of the following are true about both primary and secondary succession EXCEPT A) both lead to a stable climax community. B) both include a progression of changes in the community over time. C) both occur in regions where soil is already present. D) for both communities, fungi and vascular seedless plants are typically the first species to colonize the area. E) both are colonized first by opportunistic species.
C
All of the genes and all of their associated alleles within a population represent the population's A) genotype. B) gene flow. C) gene pool. D) genome. E) Hardy-Weinberg equilibrium.
C
As fall approaches, whitetail deer begin to accumulate a layer of body fat. This is an example of which characteristic of life? A) maintaining homeostasis B) metabolism C) response to the environment D) energy regulation E) organization
C
Critical to the theory of evolution, Darwin needed to include an idea that was not generally accepted by scientists or society at that time. That idea was A) that catastrophism occurred at a uniform rate. B) that the inheritance of acquired characteristics was true. C) that the Earth must be very old. D) that uniformitarianism was false. E) that diversity of life was constant through time.
C
If a population recovers to its original population size after experiencing a bottleneck, which statement is correct regarding this population? A) The recovered population is as likely to go extinct as is the population prior to the bottleneck. B) The bottleneck subjected the population to directional selection. C) The recovered population shows less genetic diversity that the population prior to the bottleneck. D) The recovered population shows more genetic diversity than the population prior to the bottleneck. E) The recovered population is more likely to go extinct as is the population prior to the bottleneck
C
Mitochondria are found in A) plant cells. B) animal cells only. C) both plant cells and animal cells. D) neither plant or animal cells. E) animal cells and bacterial cells only.
C
Monkeys in the New World (the Americas) have prehensile tails, strong flexible tails that grip branches and operate much like another hand while Old World (Africa and Asia) monkeys do not have such a tail. The explanation for this is A) monkeys in the Old World do not need a prehensile tail and therefore did not evolve one. B) monkeys in the New World needed a prehensile tail and therefore evolved one. C) the prehensile tail evolved in New World monkeys after the Americas separated from Africa and Asia. D) the Americas are much older than Africa and Asia. There has not been enough time to evolve a prehensile tail in Africa and Asia. a catastrophe occurred in the Old World that killed E) all prehensile tail monkeys leaving only non-prehensile tailed monkeys to survive.
C
Prior to the start of the industrial revolution around the 19th century, which of the following statements is most accurate? A) There was more photosynthesis occurring than combustion and cellular respiration. B) There was more combustion and cellular respiration than photosynthesis occurring. C) There was approximately equal amounts of photosynthesis and cellular respiration and combustion occurring. D) There was more conversion of carbon to fossil fuels occurring that either photosynthesis or cellular respiration and combustion. E) We cannot tell from the data given here.
C
Sickle cell anemia is caused by a recessive genetic disorder. Individuals who are homozygous recessive (ss) usually die before 2 years of age without medical treatment. However, a single copy of the "s" form of the gene conveys tremendous resistance to the disease malaria without tremendous negative side effect. Homozygous dominant individuals (SS) are easily infected by malaria. Malaria is often times fatal. A population of humans living in a malaria-infested environment has 88% of the children born who are phenotypically normal. Use these two equations to solve the following questions. p + q = 1 and p2 + 2pq + q2 = 1 What is the frequency of heterozygous individuals in this population? A) 0.120 B) 0.346 C) 0.453 D) 0.654 E) 1
C
The central dogma of molecular biology states that the information contained within genes flows in which direction? A) DNA to DNA to protein B) mRNA to DNA to protein C) DNA to mRNA to protein D) DNA to tRNA to mRNA to protein E) DNA to rRNA to protein
C
The concept of half-life is often used to date how old a substance or fossil is. Put simply, half-life is the amount of time it takes for one half of all of a radioactive substance to break down. For example, if I started with a bone that had 100 grams of C-14 in it, and 5730 years later the same bone only had 50 grams of C-14, then the half-life of C-14 is 5730 years. Today, sophisticated tools exist to measure the amount of radioactive compounds present in a given sample. Carbon 14 is the most commonly used radioisotope. It has a half-life of roughly 5730 years. Using the graph below to help answer the following questions: If I started with 100 grams of C-14 in a sample, how many grams would be left after 3 half-lives? A) 50 grams B) 25 grams C) 12.5 grams D) 6.25 grams E) Impossible to tell
C
The fact that DNA is the molecule containing the genetic code for all life on Earth is a part of A) comparative anatomical evidence. B) comparative embryological evidence. C) biochemical evidence. D) biogeographical evidence. E) evidence of artificial selection.
C
Unicellular organisms undergo mitotic division to A) repair damaged cells. B) increase the size of the organism. C) produce new organisms. D) increase the genetic variability of the population. E) produce gametes.
C
What does it mean when it is said that humans and apes share common descent? A) Humans descended from apes. B) Apes descended from humans. C) Apes and humans descended from the same common ancestor. D) Apes and humans are the same. E) Apes and humans did not descend from a common ancestor.
C
What statement below is correct when comparing plant and animal cells? A) Plant cells have a cell wall and animal cells have a plasma membrane. B) Plant cells have a plasma membrane and animal cells have a cell wall. C) Both plant and animal cells have a plasma membrane and plant cells also have a cell wall. D) Both plant and animal cells have a plasma membrane and a cell wall. E) Both plant and animal cells have a cell wall but only animal cells have a plasma membrane.
C
Which of the following is most likely to lead to two distinct species? A) directional selection B) stabilizing selection C) disruptive selection D) genetic drift E) bottleneck effect
C
Which of the following is true about the current state of human population growth? A) The 21st century has seen the highest global human population growth. B) Human populations tend to be evenly distributed. C) After the Industrial Revolution, population growth increased. D) The current global death rate exceeds the current global birth rate. E) The doubling-time for the human population is increasing.
C
Which of the following shows the flow of energy at the cellular level through the biosphere? A) solar energy - mitochondria - chloroplast B) chloroplast - solar energy - mitochondria C) solar energy - chloroplast - mitochondria D) mitochondria - solar energy - chloroplast E) chloroplast - mitochondria - solar energy
C
All of the following are true with respect to DNA except A) genes are made up of DNA. B) for sex cells (sperm and egg), the DNA found in every cell in your body is identical. C) offspring from sexual reproduction obtain their DNA from both parents. D) asexual reproduction results in offspring with DNA that is different from the parent. E) DNA codes for proteins.
D
If a homozygous black bull is mated with a homozygous white cow and the calf is gray, this would be an example of ___________. However, if the calf has black and white spots this would be an example of A) incomplete dominance; a sex-linked trait. B) complete dominance; polygenic trait. C) codominance; homology. D) incomplete dominance; codominance. E) a sex-linked trait; a recessive trait.
D
Microevolution is the term that applies to which of the following? A) Any evolution at any scale is considered microevolution. B) Large-scale changes over a long period of time. C) Small-scale changes over a long period of time. D) Small-scale changes over a short period of time. E) Changes of any scale within microorganisms.
D
Natural selection results in A) increased genetic variation. B) a decreased population size. C) an increase in population size. D) offspring being better adapted to their current environment. E) offspring being better adapted to a future environment.
D
Sickle cell anemia is caused by a recessive genetic disorder. Individuals who are homozygous recessive (ss) usually die before 2 years of age without medical treatment. However, a single copy of the "s" form of the gene conveys tremendous resistance to the disease malaria without tremendous negative side effect. Homozygous dominant individuals (SS) are easily infected by malaria. Malaria is often times fatal. A population of humans living in a malaria-infested environment has 88% of the children born who are phenotypically normal. Use these two equations to solve the following questions. p + q = 1 and p2 + 2pq + q2 = 1 What is the frequency of dominant allele in this population? A) 0.120 B) 0.346 C) 0.453 D) 0.654 E) 0.880
D
The greenhouse effect A) decreased sea levels. B) decreases the amount of carbon dioxide in the air. C) increases the amount of carbon dioxide in the air. D) is caused by gases such as carbon dioxide trapping heat in the Earth's atmosphere. E) is due to gases forming a barrier around the Earth and insulating the Earth from the sun's rays.
D
The second law of thermodynamics states that all energy transformations result in more disordered energy. How can photosynthesis take more disordered carbon dioxide and water and convert them into glucose which is more ordered? A) living things do not obey the laws of thermodynamics B) this is an illusion, it only appears that glucose is more ordered C) photosynthesis is an exception to the second law of thermodynamics D) solar energy is being added to the reaction to create glucose E) plants are able to harness entropy and use it to carry out photosynthesis
D
There is an antibiotic called streptomycin that doctors prescribe for infection. The antibiotic combines with the bacteria's ribosomes causing them to lose their function. Consequently the cell dies and so the person gets better! In other words, the antibiotic destroys bacteria by A) stopping photosynthesis. B) preventing them from packaging materials. C) stopping the production of ATP energy. D) not allowing them to produce proteins. E) stops them from being able to move.
D
What does the folding of the mitochondrial inner membrane shown here provide? A) greater ability to allow for osmosis B) increased surface area for photosynthesis C) greater ability to remove waste from the cell cytosol D) greater surface area for ATP production E) increased space for protein synthesis
D
When an animal respires, the carbon in the carbon dioxide that it breathes out comes indirectly from A) the air that the organism breaths in. B) dead and decaying plant matter. C) fossil fuels. D) photosynthesis. E) carbon fixation.
D
When hiking high in the mountains, you find fossil marine shells lying about. This provides evidence that A) someone brought the shells to the top of the mountain. B) shelled marine animals live on the top of mountains. C) very high ocean waves brought the shells to the top of the mountain. D) the mountain top was once under the ocean and has been uplifted. E) marine animals are not restricted to living in the ocean.
D
Which of the following is NOT a function of the endomembrane system? A) prepares molecules for export from the cell B) provides a place for produced cellular materials to be refined C) manufactures molecules D) acts as the control center of the cell E) assists in moving materials from one part of the cell to another
D
Which of the following is a community? A) a group of walrus on a beach B) hummingbirds at a feeder C) trout and the lake they inhabit D) squirrels and the oak trees they live in E) a herd of elephants in the Namib desert
D
Which of the following lists the terms from simplest to most complex? A) cells, organs, tissues, organ systems, organism B) organs, organ system, organism, cells, tissues C) tissues, organs, organ systems, organism, cells D) cells, tissues, organs, organ systems, organism E) organ systems, tissues, cells, organism, organs
D
Which of the following processes does not contribute to creating genetic variability in the offspring? A) crossing-over B) independent assortment of chromosomes C) pairing of homologous chromosomes D) interkinesis E) different alleles of the same gene
D
Which statement about ecology and environmental science is correct? A) Ecology is a field of science that helps negate the information that is derived from the field of environmental science. B) During the study of ecology only living organisms are studied while the nonliving aspects are studied within the field of environmental science. C) During the study of environmental science living organisms are studied while the nonliving aspects are studied within the field of ecology. D) The field of environmental science applies the ecological principles to human based concerns. E) The field of ecology focuses on human based issues and uses them to help determine if there is going to be an environmental change.
D
Wings of insects and birds are result of convergent evolution. This means that A) these organisms are unrelated but have similar adaptations. B) these organisms share a recent common ancestor and so have similar adaptations. C) these organisms have different adaptations to different environments. D) insects and birds have each independently evolved structures that serve the same function (flight) but have done so in very different ways. E) the insects and birds must be related to possess such similar qualities.
D
A woman inherits a mutant BRCA1 allele from her mother. She has an increased risk of developing breast cancer because A) every cell in the woman's body has a copy of the mutant BRCA1 allele. B) she still has one normal allele of the BRCA1 gene that can make up for the loss of function in the mutant allele. C) some of the cells in her body are already cancerous, meaning that no further mutations are needed for a tumor to form. D) the normal BRCA1 allele is more likely to mutate than in an individual without a mutant BRCA1 allele. E) a mutation in her normal BRCA1 allele may lead to cancer, whereas a normal individual would have to acquire two mutations (one in each allele) to develop cancer.
E
Cancer occurs when A) cells are unable to divide because of a mutation. B) faulty spindle fibers are unable to pull chromatids apart. C) apoptosis occurs. D) both uncontrolled cell division and stimulation of apoptosis occurs. E) the regulation of the cell cycle is lost and uncontrolled cell division occurs.
E
Cells grown in a petri dish tend to divide until they form a thin layer covering the bottom of the dish. If cells are removed from the middle of the dish, the cells bordering the open space will begin dividing until they have filled the empty space. What does this experiment show? A) When cells come into contact with other cells, they stop growing. B) The controls on cell growth and division can be turned on and off. C) Cell division can be regulated by factors outside of the cell. D) Cells continue to grow as long as there is adequate space. E) All answers are valid and correct.
E
Since the plasma membrane blocks the passage of all but a few molecules with specific traits it is necessary for other molecules to A) pass through the membrane via pores made of carbohydrates. B) be broken down into their constituent atoms to move through the membrane. C) be converted into other types of molecules so that they meet the specific traits necessary. D) pass through the membrane via nucleic acids. E) pass through the membrane via proteins.
E
Which of the following is NOT true with regard to the law of segregation? A) Each individual has 2 factors for each trait. B) Genes segregate during gamete formation. C) Gametes contain only 1 gene from each pair. D) During fertilization, each new individual obtains 2 genes for each trait. E) Each gamete contains 2 genes for each trait.
E
Which of the following organelles is not surrounded by a membrane? A) nucleus B) chloroplast C) mitochondrion D) lysosomes E) ribosomes
E
