NES biology
A certain trait is a sex-linked trait and the phenotype only shows up in males. If a male with the phenotype mates and produces offspring with a female that does not carry the trait, what are the chances that their male offspring will show up with the phenotype for the sex-linked trait? 100% 75% 25% 0%
0% A sex-linked trait is passed to offspring by a gene on the X chromosome. Boys are XY, and a man with a sex-linked phenotype only passes on his Y chromosome, so his sons will not inherit the sex-linked trait.
Placed side by side, how many atoms would it take to make a row 1 cm long? 100 1 million 100 million 1 billion
100 million Atoms are incredibly small, and placed side by side, 100 million atoms would make a row about 1 cm long.
Huntington's Disease is a heritable illness that destroys neurons and causes movement and behavioral disorders. If a person has a single copy number of the abnormal Huntington gene, and they live long enough, they will certainly develop the Disease. Based on the information above, which of the following describes Huntington's Disease? Autosomal recessive. X-linked recessive. 50% penetrant. 100% penetrant.
100% penetrant. Huntington's Disease is autosomal dominant with 100% penetrance. That means that it is inherited on an autosomal chromosome, and only one gene copy number is needed to cause the Disease. The fact that all who have the abnormal gene get the Disease means that it is 100% penetrant. If the trait were autosomal recessive, a single copy number would not cause the Disease.
In frogs, a solid spot pattern and dorsal folds are both autosomal recessive traits. Two frogs have one copy of the allele for both traits. If they mate, and the genes are independently assorted, what is the probability that the offspring will have both a solid spot pattern and dorsal folds? 25%. 50%. 6.25%. Less than 1%.
6.5% In order to have progeny with both recessive traits, the offspring must have two (2) copies of both recessive alleles. The chance of that happening with one allele is 25%, but the chance of it happening with both alleles is 25% of that, or 6.25%. 25% of 25% = 0.25 * 25% = 6.25%
What characterizes imprinting? -A limited sensitive time period. -The species. -The ability of the animal to focus on certain stimuli. -Physiological response to stimuli.
A limited sensitive time period. Imprinting is learning that occurs only during a certain, limited and sensitive time period in development. Mother-offspring imprinting is critical to survival of many offspring, such as ducks and geese. The timing and duration of the sensitive period in which sexual imprinting may occur in different animals varies.
On cutting a section of nitrogen fixing root nodule ,central portion appears to be red or pink in colour. This is because of the presence of leghaemoglobin. What is correct about this pigment? -Imparts color to nodules -Act as oxygen scavenger -Helps in circulation of oxygen -Provides nutrition
Acts as oxygen scavenger The central red to pink portion of nitrogen fixing nodule is due to the presence of leghaemoglobin.It is a necessary biochemical component of nodule.It helps in protection of Nitrogenase enzyme(converts nitrogen to ammonis) which is sensitive to oxygen. So to protect these enzymes this leghaemoglobin acts as a oxygen scavenger .
Which of the following terms refers to the roots that are formed by meristems growing from other parts of the plant? Taproots. Adventitious roots. Lateral roots. Fibrous roots.
Adventitious roots. Not all new roots arise as lateral outgrowths of previously existing roots. Adventitious roots are formed by meristems growing from other parts of the plant. For example, a mature corn plant has many roots that arise adventitiously (or by chance) from the base of the stem.
Which life history characteristics can affect the number of offspring that an individual will produce? -The number of reproductive episodes per lifetime. -Clutch size. -Age at first reproduction. -All of the above
All of the above Some organisms only reproduce once in their lifetime, such as the Pacific salmon; and some organisms reproduce more than once, such as mammals. Clutch size refers to the number of offspring that results from each reproduction episode. Generally, organisms that have a large clutch size tend to produce smaller offspring, and vice versa. Organisms that start reproducing earlier will generally have more offspring over their lifetimes. The correct answer therefore, is (D).
Which of the following relationships is most likely to result in co-evolution? flower and pollinator parasite and host predator and prey All of the above
All of the above Co-evolution occurs between two species that spend a long time interacting a direct and dramatic way. Predators become better at hunting and prey becomes better at escaping. Parasites get better at evading the host's defenses, causing the host to develop better means of defense. Flowers develop better ways to take advantage of pollinators and pollinators evolve better ways to find and consume nectar.
Leaves of Citrus and Cladodes of Ruscus are examples of? Analogous organs Homologous organs Vestigeal organs None of the above
Analogous organs The organs which have the same function and are superficially alike but are quite different in fundamental structure and embryonic origin are called the analogous organs. Both of these look alike and serve to carry on photosynthesis, but have different structure.
In what oceanic zone are chemoautotrophic prokaryotes found? Benthic zone. Pelagic zone. Intertidal zone. Neritic zone.
Benthic zone Organisms that occupy benthic regions are specially adapted to darkness, cold and high water pressure. Chemoautotrophic prokaryotes are a collection of organisms that are specifically adapted to the hot, low-oxygen environment surrounding deep sea hydrothermal vents.
Diabolical Dave creates an intelligence drink that he wants to show can make people smarter. He assigns all high school seniors to one group, and gives them the drink; and assigns all high school freshman to another and does not give them the drink. After giving both groups a calculus test, he claims that his intelligence drink makes high school students smarter. Which experimental errors has Diabolical Dave committed? A. Lack of placebo control. B. Selection bias. C. Statistical variability. D. Both A and B.
Both A and B. Diabolical Dave has introduced selection bias into his experiment because he has knowingly grouped students into control and experimental groups. Seniors would be expected to perform better than freshmen on a calculus test. Also, when subjects are given something to swallow, eat, or drink, the control group should be given a placebo when possible; or something that does not contain the substance being tested.
How are plants distinguished from multicellular algae? -Plants have cell walls made of cellulose. -By adaptations that are unique to terrestrial life. -By photosynthesis. -By sporopollenin.
By adaptations that are unique to terrestrial life Plants are defined as multicellular eukaryotes that are photosynthetic autotrophs. However, these characteristics also apply to some algae. In fact, there are many similarities between plants and some algae, in particular brown algae and it is difficult to differentiate the two by characteristics alone. There are some who feel that brown algae should, in fact, belong to Kingdom Plantae. Generally, plants are distinguished from multicellular algae by their adaptations that are unique to terrestrial life. Most plants are terrestrial and have developed a set of structural, chemical and reproductive adaptations that are different from algae in many respects.
Which of the following processes does NOT produce ATP? Calvin cycle Krebs cycle light-dependent reactions anaerobic cellular respiration
Calvin cycle The Calvin cycle is the only process that does not produce ATP. Instead, the Calvin cycle uses the energy from ATP to build sugar molecules.
Which of the following is not a major difference between centipedes and millipedes? -Centipedes can bite if provoked, while millipedes do not bite if provoked. -Centipedes bear one leg per body segment, while millipedes have two pairs per segment. -Millipedes eat decaying material, while centipedes are terrestrial carnivores. -Centipedes have approximately one hundred legs, while millipedes have about one thousand legs.
Centipedes have approximately one hundred legs, while millipedes have about one thousand legs. There are some significant differences between the similar-looking centipede and millipede; and the number of legs is the least impressive. The centi- and milli- prefixes do not directly equate to the number of legs.
What is a succession of rapid cell divisions during which an embryo divides into many small cells? Cleavage. A cortical reaction. Epigenesis. Involution.
Cleavage Cleavage partitions a zygote into many smaller cells. It is a rapid succession of cell divisions that divide the embryo into many small cells called blastomeres.
Which of the following inhibition types can be easily overcome by an increment in substrate concentration? -Competitive inhibition -Uncompetitive inhibition -Noncompetitive inhibition -Mixed inhibition
Competitive inhibition Competitive inhibitors attempt to battle with the substrates for creating a bond with the enzymes while substrate is trying to do so, as this inhibitor gets attracted to an enzymes active site.
Which of the following types of leaves are made up of leaflets? Simple leaves. Compound leaves. Monocot. Dicot.
Compound leaves. A compound leaf is composed of several leaflets, in which the cells in some areas do not divide at all; and each leaflet appears to be, but is not, a separate leaf.
Ligands bind to cell membrane receptors in order to cause an action in the cell. Which of the following types of binding would not occur in biological systems? Hydrogen Hydrophobic Covalent van der Waals
Covalent Ligands bind to receptors briefly and then dissociate. Thus when a signal reaches a cell, temporarily bind, exerts its effect and leaves. If the ligand covalently bonded to the receptor, the cell would be perpetually stimulated and the receptor would no longer be useful as a sensing device.
Which of the following is an example of biological magnification? DDT smog extinction pollution
DDT Biological magnification is a process where concentrations of a harmful substance increase in organisms at higher trophic levels in a food chain or food web. Biological magnification affects the entire food web, althought top-level carnivores are at the highest risk. DDT is a pesticide that affects whole food webs. If it gets in water, aquatic plants store it in their tissues, Herbivores that eat the plants store the pesticide as well, and the concentration increases the more plants the herbivore eats. Carnivores that eat the herbivores increase the concentration of the pesticide in their tissues as well.
Which molecule would tend to migrate towards the positively charged electrode in a pH 7 solution? DNA Potassium Sodium Lysine (mostly positively charged at pH 7)
DNA Negatively charged ions move towards positive electrodes and vice versa. Potassium, sodium and lysine are all positively charged and will not move towards the positive electrode. DNA has a phosphate backbone which gives the molecule a negative charge. That is why DNA electrophoresis gels are set up so that the wells are near the negative charge so that the DNA samples can migrate towards the positive electrodes.
When this DNA sequence is replicated, AATCCGATT, the daughter cell receives this sequence, AATCGATT. Which type of mutation has occurred? Duplication Inversion Deletion Insertion
Deletion Apparently one of the cytosine residues was not transcribed properly, thus a deletion has occurred. If this mutation occurs in a region of DNA that is used to code for a protein, it may lead to problems for the daughter cell and its progeny.
Why are eukaryotic cells within an organism different? For example, skin cells are different from neurons. -They contain different DNA -They contain different genes -Each has chromosomes unique to the cell -Different genes are expressed in each cell type
Different genes are expressed in each cell type The entire genome is present in every cell formed by mitosis in the body. Obviously the genes and DNA must be the same. Therefore, what make cells different from one another is the genes that are expressed in each cell. Even though all the genes for a skin cell are present in nerve cells and vice versa, many of the genes that are expressed in a nerve cell are different from a skin cell.
The enzymatic hydrolysis of macromolecules into monomers that can be absorbed across cell membranes is more commonly known as what? Osmosis. Digestion. Absorption. Circulation.
Digestion Animals eat other organisms to obtain fuel to carry out their bodily functions. Digestion is the enzymatic hydrolysis of macromolecules into monomers that can be absorbed across cell membranes.
Instead of the term, phylum that is used in the animal kingdom, plant biologist use a different term for the plant kingdom. Which of the following is the term that is used to describe the highest level of taxonomic classification within the Kingdom Plantae? Class. Order. Family. Division.
Division. The term, division, is used by plant biologists to describe the 12 major plant groups within the Kingdom Plantae. Like phyla, divisions are subdivided into classes, orders, etc. The use of the term, division, is intended to help organize the plant kingdom and place its various divisions into historical and evolutionary perspective. The correct answer therefore, is (D).
When a chromosome fragment joins to a sister chromatid during meiosis, or to the homologous chromosome, this is called what? Crossing over. Translocation. Duplication. Inversion.
Duplication Chromosome fragments can join a sister chromatid during meiosis or the homologous chromosome. This is called duplication.
Which of the following are mismatched? -Whale - internal gonads. -Many rodents - gonads are external during breeding season and drawn back into the body at other times. -Monotremes - internal gonads. -Elephants - external gonads.
Elephants - external gonads Production of normal sperm cannot occur at the normal body temperature of most mammals. Many mammals testes are held outside the abdominal cavity in the scrotum to keep the temperature about two degrees Celsius below the body temperature. In many rodents the testes are drawn back into the abdominal cavity to interrupt sperm maturation between breeding seasons. Some mammals whose body temperature is low enough to allow sperm maturation, retain the testes within the abdominal cavity.
What is the effect of the hormone known as ethylene? -It initiates cell division. -High concentration of ethylene stimulates the production of auxin. -It is responsible for geotropic response in roots; and promotes the onset of dormancy. -Ethylene promotes the ripening of fruit; and counteracts the effects of auxin.
Ethylene promotes the ripening of fruit; and counteracts the effects of auxin. Ethylene plays a role in both, the senescence of plants and in the ripening of fruits. The development of a fruit is stimulated by auxin, gibberellin, and cytokinin. The auxin level builds up and then drops; followed by the production of ethylene. Ethylene stimulates the activity of some enzymes that softens (or ripens) fruit by breaking down pectins in the fruit cell walls.
The coding regions of RNA are called which of the following? Codons. Introns. Exons. Ribozymes.
Exons Long segments of non coding base sequences are known as introns. These sequences occur within the genes of eukaryotes, The remaining coding regions are called exons and they are expressed in protein synthesis. During transcription, a primary transcript is made of the gene, then the introns are removed and the exons are joined before the mRNA leaves the nucleus.
Which of the following confirms the commencement of DNA synthesis? -G1 checkpoint control mechanism -G2 checkpoint control mechanism -M phase -S phase
G1 checkpoint control mechanism G1 checkpoint control mechanism makes sure that DNA synthesis can now be begun.
Which of the following is the process by which inheritable information from a gene (such as DNA sequence) is made into a functional gene product, such as protein or RNA? Gene-building. Gene expression. Gene-matching. Gene-encoding.
Gene expression. The type of gene regulation control over the timing, location, and amount of gene expression can have a profound effect on the function of the organism. The correct answer therefore, is (B).
Which of the following is the term used to describe undesirable gene flow into wild populations, that is often used to describe the gene flow from a genetically-modified organism (GMO) into a non-genetically modified organism? Genetic modification. Gene swapping. Gene translocation. Genetic pollution.
Genetic pollution. The use of the term, genetic pollution is controversial because what is genetic pollution (assumed to be deleterious) and what is not, can be highly subjective. The correct answer therefore, is (D).
Which of the following would NOT alter DNA molecules? Reactive chemicals. X-rays. UV light. Infrared light.
Infrared light DNA molecules may be altered or damaged by reactive chemicals, X-rays, UV light or radioactive emissions. These alterations may be repaired by many different types of DNA repair enzymes.
Unlike primary growth, secondary growth in both roots and stems is which of the following? -Is indeterminate. -Produces xylem and phloem. -Involves vascular cambium and cork cambium. -Is a function of meristematic tissue.
Involves vascular cambium and cork cambium. The increase in girth of stems and roots is due to the secondary production of new cells by the vascular cambium and the cork cambium, both lateral meristems.
The notion that the number of species found on an undisturbed island is determined by immigration, emigration, and extinction is known as the theory of which of the following? Island Biogeography. Area Geomorphology. Land Biogeography. Habitat Geomorphology.
Island Biogeography. In population ecology, the word, island is used to denote an area of usable habitat within an area of unusable habitat. The idea has use beyond the traditional island (area of land within a body of water) concept.
Why is the shape of a molecule crucial in biology? -It determines whether or not the molecule is active or inactive. -It determines whether or not the molecule is organic and part of a life process. -It determines how most molecules of life recognize and respond to one another. -The shape is not critical in biology. The elemental composition of the molecule is important.
It determines how most molecules of life recognize and respond to one another Molecular shape is important in biology because it determines how molecules of life recognize and respond to one another. An example is in the brain. One cell in the brain releases molecules of a certain shape that are complementary to the shape of receptor molecules on another brain cell. This is how signals pass from cell to cell.
A biochemist determines that the effect of an enzyme inhibitor can be overcome by adding additional substrate to the reaction vessel. What can be said about the inhibitor? It is noncompetitive It is competitive It is a suicide substrate It is not a true inhibitor
It is competitive The enzyme inhibitor is competitive. We know this because as additional substrate is added to the solution, it can overcome the inhibitor. As the name implies competitive inhibitors compete with the substrate for the active site of the enzyme. The competition is concentration dependant. Noncompetitive inhibitors and suicide substrates are unaffected by substrate concentration.
What is the effect of the hormone known as abscisic acid? -It is responsible for geotropic response in roots; and promotes the onset of dormancy. -High concentrations of abscisic acid stimulate the production of ethylene. -Abscisic acid initiates cell division. -Abscisic acid promotes the ripening of fruit; and it counteracts the effects of auxin.
It is responsible for geotropic response in roots; and promotes the onset of dormancy. Abscisic acid, another plant hormone, is chiefly a growth inhibitor. It is produced in mature leaves and is transported to the rest of the plant. When its concentration in twigs is high, in comparison to other hormone levels, it induces dormancy at the end of the growing season.
Which of the following is true of the primary growth of a tree? -It occurs through the activity of the vascular cambium. -It occurs through the activity of the root cap. -It occurs only in the first year of the life of the tree. -It occurs through the activity of the apical meristem.
It occurs through the activity of the apical meristem. The apical meristem consists of a small mound of rapidly dividing cells. The cells just below the shoot apical meristem elongate and then mature into differentiated cells of the primary plant stem (or tree trunk in this case). The growth period in cells of the shoot (in both length and diameter) may last longer than the growth period in the root; so growth in the shoot can be detected quite a distance behind the growing tip of the apical meristem.
If an animal cell is placed in a hypotonic solution, what will happen to it? It will shrink It will swell The cell wall will become turgid The cell will actively absorb water
It will swell The cell membrane of animal cells will take on the osmolarity of the surrounding solution once normal processes govern osmotic regulation are overwhelmed. Therefore, if an animal cell is placed in a hypotonic solution, meaning a solution that has less solute than inside the cell, the system will move toward equilibrium and the cell will swell. The cell will take on water because the inside of the cell is relatively hypertonic. Animal cells do not have cell walls. If any cellular compensation were to occur, the cell would try to prevent water from being absorbed.
Which of the following persons made a compound microscope by placing two convex lenses at each end of a tube? Hooke Janssen Brown Schwann
Janssen In the 1590s, Zacharias Janssen and his father made a compound microscope by placing two convex lenses at each end of a tube. Robert Hooke used a compound microscope to observe cork from the bark of the cork oak tree and saw small, empty box-like structures that he named cells. Brown, working with orchid and other plant cells, saw a small structure inside the cells he named the nucleus. Schwann, who worked with animals, stated that all animals are made of cells.
Which of the following fish does not have jaws? Manta ray. Eel. Basking shark. Lamprey.
Lamprey Lampreys are eel-like, fish that do not have scales, have a cartilage skeletal structure, and have a round, jawless mouth. There are freshwater and saltwater lampreys. Lampreys have recently become an ecological problem in the Great Lakes of North American, where they are an invasive species. There are some who do not consider lampreys to be fish at all. There are many differences they exhibit compared to bony fish. Unlike bony fish, their fins are not paired, they have one nostril and have a third pineal eye on top of their head. They have 7 gills on each side. They have no vertebral column, but instead, their body is supported by a notochord.
Proteins made by free ribosomes are what? -Inactive. -Made to be transported out of the cell. Made to function within the cytosol. -Part of cell replication.
Made to function within the cytosol Free ribosomes manufacture proteins within the cytosol. The proteins made by free ribosomes are made to function within the cytosol.
What best describes the heterosporous nature of a conifer? -Both male and female gametophytes develop within the same cone. -Male and female gametophytes develop in different cones. -Gametophytes are bisexual. -Female gametophytes are contained inside cones. Male gametophytes are released from anther structures.
Male and female gametophytes develop in different cones Conifers, like all seed plants are heterosporous. In confers male and female gametophytes develop from different types of spores produced by separate cones. Each tree normally has both types of cones. The cones that produce pollen are smaller. The ovulate cones are larger and usually develop on separate branches of the tree.
Which of the following is true regarding the movement of sap from a sugar source to a sugar sink? -Occurs through the apoplast of sieve-tube members. -May translocate sugars from the breakdown of stored starch up to the leaves -Is primarily a passive process. -Results mainly from diffusion.
May translocate sugars from the breakdown of stored starch up to the leaves The sieve tubes of the phloem carry food and other solutes from a sugar source to a sugar sink. The source is a plant organ that produces sugar by photosynthesis or the breakdown of starch (leaves are usually the source), whereas a sugar sink is a plant organ that consumes or stores sugar (growing roots, shoot tips, and fruits are sugar sinks supplied by phloem). A storage plant organ, such as tubers or bulbs, can either be a source or a sink, depending on the season.
If you placed an animal in a calorimeter and measured heat loss, you would be measuring its what? Temperature. Body Mass Index. Metabolic rate. Body Heat Index.
Metabolic rate The total energy an animal uses in a given amount of time is its metabolic rate. Energy is measured in calories or kilocalories. Metabolic rate can be measured by placing an animal in a calorimeter and measuring its heat loss.
Which of the following is NOT a function of smooth endoplasmic reticulum (ER)? -Synthesis of lipids. -Metabolism of proteins. -Metabolism of carbohydrates. -Detoxification of drugs and poisons.
Metabolism of proteins Smooth ER has various functions in metabolic processes. These functions include: synthesis of lipids, metabolism of carbohydrates, and detoxification of drugs and poisons. Enzymes in the ER are critical to the synthesis of lipids.
The cytoplasm of a cell has what type of charge compared to the extracellular fluid? Positive. Negative. Equal. Double.
Negative The cytoplasm of a cell is negative in charge compared to the extracellular fluid. This is due to an unequal distribution of anions vs. cations on opposite sides of the cellular membrane.
Two people carry one copy of a recessive gene that causes sickle cell anemia. They have eight (8) children together. How many children have the Disease? One (1). Two (2). Four (4). Not enough information.
Not enough information. Based on Mendelian genetics, each offspring has a one (1) in four (4) chance of inheriting two copies of the recessive gene which will result in sickle cell disease. That is only a probability however, and is not a rule. If the couple has eight (8) children, any number between one (1) and eight (8) of them could have the Disease since the trait is conferred to each child at the time of conception. It is like flipping a coin many times in row. No matter how many times that the coin is flipped, there is still a fifty percent (50%) chance of it landing on heads.
What is produced as a result of the 5' - 3' direction of DNA replication? Deletion. Replication bubbles. Okasaki fragments. Sugar-phosphate backbones.
Okasaki fragments Due to the fact that DNA is replicated in a 5' - 3' directions, the lagging strand is replicated in a series of short fragments called Okazaki fragments. They are formed in the 5' - 3' direction, away from the replication fork.
Which of the following species mentioned below has the maximum number of chromosomes? Ophioglosum sp. Haplopappas gracilis Felis catus Triticum aestivum
Ophioglosum Ophioglosum is a pteridophyte and it posses the maximum number of chromosome 2n=1656 .On the other hand Haplopappas has the lowest number of chromosome 2n=4.Felis catus and Triticum aestivum posses 42 and 38 respectively.
The RNA viruses that cause influenza belong to the family? Orthomyxoviridae Rhabdoviridae Togaviridae Paramyxoviridae
Orthomyxoviridae Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae (the influenza viruses), that affects birds and mammals.
Which of the following refers to polymorphism with an environmental trigger that results in different phenotypes under different environmental conditions? Polyphenism. Enviropolymorphism. Biomorphism. Monomorphism.
Polyphenism. A polyphenic trait has multiple distinct phenotypes despite having only a single genotype. One example of polyphenism is a species' ability to alter sex determination with a ratio of male to female offspring other than 1:1 that would benefit the population.
Which of the following biological structures is not primarily composed of amino acids? Enzymes. Ion channels. Antibodies. RNA.
RNA. RNA, or ribonucleic acid is composed primarily of nucleic acid, not amino acid. Amino acid and, by extension protein, make up an enormous number of biological structures.
What is one possible explanation for altruism that occurs between non-related individuals? -Co-efficient of fitness. -Proximity. -Reciprocal altruism. -Hamilton's rule.
Reciprocal altruism Altruism is difficult to explain between non-related individuals, since it reduces the fitness of the individual and increases the fitness of the recipient. One possible explanation is the idea of reciprocal altruism. This explanation theorizes that while there is no immediate benefit for the altruistic individual, some future benefit may occur if the recipient "returns the favor".
Which of the following is NOT a function of tumor-suppressor proteins? -Repair of damaged DNA. -Control of cell adhesion. -Inhibition of the cell cycle. -Recognition and degradation of proteins marked for destruction.
Recognition and degradation of proteins marked for destruction Mutations in tumor suppressor genes can contribute to the onset of cancer if the mutation results in a decrease in the activity of tumor suppressor proteins. These proteins prevent uncontrolled cell growth. They also repair damaged DNA, control cell adhesion and inhibit the cell cycle. Proteasomes recognize and degrade proteins that are marked for destruction and serve as a different type of control mechanism within the cell, not necessarily related to cancer.
Which of the following is NOT a function of the human kidney? -Production of the hormone erythropoietin. -Maintenance of electrolyte balance. -Help control blood pressure. -Recycling of red blood cells.
Recycling of red blood cells The kidney performs a wide range of functions in a healthy human body. It removes wastes and water from the blood, produces the hormone erythropoietin to increase production of red blood cells, helps maintain electrolyte balance, helps control blood pressure, and helps produce vitamin D.
In most animals, oxygen is carried by what in the blood? Partial pressure. Myoglobin Respiratory pigments. Bicarbonate ions.
Respiratory pigments Respiratory pigments transport gases in the blood in most animals. Copper is the oxygen-binding component in the blue respiratory protein hemocyanin, which is common in arthropods and many mollusks. Hemoglobin, contained in red blood cells is the respiratory pigment for most vertebrates.
Which of the following is the ultimate source of most soil minerals? Rock particles. Organic matter. Living organisms. Water.
Rock particles. Plants take up most of the water and minerals that they need from the soil and the soil quality and its constituents, which are mainly determined by the type of rock from which it is derived.
The fungal group mycorrhizae form mutualistic associations with what? Animal hosts. Soil. Roots. Insects.
Roots Mycorrhizae as a group of fungus that form mutualistic associations with the roots of plants. This association is symbiotic meaning it is advantageous for both organisms. The macrosymbiont (the plant) gains increased exploration of the soil with the intricate net of hyphae from the fungus. This increases the uptake of water and nutrients from the soil. The microsymbiont (the fungus) uses the carbon provided by the plant for its physiological functions, growth and development.
Which phase of the cell cycle is dedicated for the replication of DNA? G1 G2 S G0
S Phase S (synthesis) of the cell cycle is dedicated to DNA replication. In this phase of cell cycle, chromosome have two sister chromatids.
This division of the nervous system brings information to the central nervous system. Sensory division. Motor division. Parasympathetic division. Sympathetic division.
Sensory division The peripheral nervous system carries information to and from the central nervous system. The peripheral nervous system consists of the sensory division which carries information to the central nervous system, and the motor division which carries signals away from the central nervous system.
Who was the scientist most well known for operant conditioning? Darwin. Pavlov. Watson. Skinner.
Skinner BF Skinner was an American behavioral scientist who is best known for his studies of operant conditioning. Reinforcement processes were emphasized by Skinner, and were seen as primary in the shaping of behavior. Skinner asserted that positive reinforcement is more effective at changing and establishing behavior than punishment.
Which of the following is mismatched? -Gonads - gamete producing organs. -Cloaca - a common opening for reproduction, excretion and digestion. -Baculum - a bone that stiffens the penis, found in some mammals. -Spermatheca - sperm transferring organ found in male insects.
Spermatheca - sperm transferring organ found in male insects In many species of insects the spermatheca is found in the female reproductive system. The spermatheca is a sac in which sperm may be stored for a year or more.
Which of the following is not made up chiefly of amino acids? Protein Peptide Collagen Starch
Starch Starch is a storage molecule for glucose or other sugars, particularly in plants. The other molecules are comprised almost entirely of protein. Collagen is a structural protein as opposed to a globular protein (e.g. enzymes).
An animal that sifts small food particles from the water is what? Fluid feeder. Substrate feeder. Deposit feeder. Suspension feeder.
Suspension feeder Most animals are opportunistic and eat foods from different categories if they become available. Many aquatic animals are suspension feeders. They sift small food particles from the water.
The first law of thermodynamics states what? -Heat = energy. -Energy is created by work and used for work. -Energy is an open loop system. -The amount of energy in the universe remains constant.
The amount of energy in the universe remains constant The first law of thermodynamics, also called conservation of energy, states that the total amount of energy in the universe is constant. The energy has to end up somewhere, either in its original form or in a different form. We can use this knowledge to help calculate the amount of energy in a system, the amount lost as waste heat, or the efficiency of the system.
Which of the following is not true in relation to jellyfish? They have a hydroskeleton and use water for structural support. -They are strict herbivores. -They may reproduce sexually or asexually. -They are the first animal phylum to possess a nervous system.
They are strict herbivores. Jellyfish make up the members of the Phylum Cnidaria. They are the first animals known to have had a primitive nervous system; a non-centralized nerve network. Their structural support requires water inside of a hydroskeleton, thus they cannot survive out of water. Jellyfish do not possess a true muscle per se, but rather more of a primitive structure that permits some movement. Jellyfish are actually carnivores, and use tentacles to draw in prey.
Which of the following is not true about Porifera (sponges)? -They may reproduce sexually or asexually. -They digest food by phagocytosis. -They need water for hydroskeleton support. -They are the earliest eumetazoa.
They are the earliest eumetazoa. Sponges, or members of the phylum, Porifera, are somewhat unique among the animal kingdom. They are quite simple anatomically, and are said to live "beside the animals" and carry the name, parazoa. Eumetazoa is the name given to all other phyla of animal, except Porifera. All of the other statements about sponges are true.
How many cytokineses, or cell divisions, have occurred from the time a single diploid animal cell undergoes meiosis and has reached the spermatid stages? One Two Three Four
Three While four spermatids are formed from each diploid cell during meiosis, two cell divisions have taken place. There is one cytokinesis at the end of telophase I forming two cells from the original diploid cell. Then each of the new haploid cells splits again at the end of telophase II to form four gametes. Thus three cell divisions have occurred.
Which one of the following hormones is the peptide hormone in nature? Testosterone Vasopressin Cortisol Estrogen
Vasopressin Vasopressin is a peptide hormone that works in the tubules of the kidneys and controls the re-absorption of molecules. Thus, it plays an important role in the regulation of water, salt and glucose in the body.
In the window-period of HIV infection, the best laboratory tool to diagnose Viral RNA and associated protein molecules is: ELISA Serological Tri-dot Assay Western Blotting RAPD
Western Blotting Western blotting is the confirmatory diagnosis for the HIV-infected patient in window period. The exact amount of viral proteins and the anti-HIV antibodies can be detected, even in the trace levels.
Which of the following describes an attraction between molecules of different substances? cohesion adhesion compound ionic bond
adhesion Adhesion is an attraction between molecules of different substances. Stickers and tape have strong adhesive properties. When water forms drops on a leaf, adhesion keeps them in place. Cohesion is an attraction between molecules of the same substance. Because of hydrogen bonding, water is extremely cohesive. Cohesion explains why some insects and spiders can walk on a pond's surface.
There is a population of a certain species of animal that annually rises above its carrying capacity, then falls far below it. Which of the following groups does the species most likely belong to? primates aves arthropoda carnivora
arthropoda Every year arthropoda, which includes insects, produce a lot of offspring, which causes the population to go over the carrying capacity. Since arthropoda go so far over carrying capacity, many offspring are eaten or die of starvation, which causes the population to fall. This does not happen with primates, carnivores, or birds.
All of the following are common subatomic particles in ordinary matter EXCEPT: protons neutrons atoms electrons
atoms Atoms are made up of subatomic particles and the most common subatomic particles in ordinary matter are protons, neutrons, and electrons. Protons and neutrons are located in the center, or nucleus, of an atom while electrons orbit the nucleus of the atom.
Which of the following animals is most likely to be an r-selected species? tiger elephant parrot bullfrog
bullfrog A species that produces a lot of offspring and lets them fend for themselves, meaning most of them will die, is an r-selected species. Larger animals typically produce a few young and then try to take care of them.
When mosses reproduce, they produce thin stalks containing which of the following? flowers seeds capsules spores
capsules Each moss plant has a thin, upright shoot that looks like a stem with tiny leaves. These are not true stems or leaves, however, because they do not contain vascular tissue. When mosses reproduce, they produce thin stalks, each containing a capsule. This is the sporophyte stage.
Between cells in most animal tissues, gap junctions are formed by which of the following proteins? plasmodesmatas connexins adherens glycoproteins
connexins In almost all animal tissues, gap junctions are formed by proteins called connexins, that form little rings in the membranes of cells. The rings on two adjacent cells line up with each other and connect together so that the open centers of the protein rings, called pores, are aligned. The connected rings of proteins form the walls of a little tunnel that passes between the two cells, and ions and small molecules can travel through the tunnels from one cell to the next. In response to signals, the protein rings can pull together, closing the opening to the tunnel and blocking the movement of materials.
All of the following are functions of the excretory system EXCEPT: -modifying blood contents -controlling the exocrine glands - modifying blood pressure -filtering wastes from blood
controlling the exocrine glands The excretory system includes the kidneys and the bladder. The kidneys filter wastes from the blood which in turn modifies blood pressure and blood contents. The exocrine glands are not part of the excretory system.
All of the following are examples of basidiomycetes EXCEPT: cup fungi puffballs jelly fungi earthstars
cup fungi Puffballs, earthstars, and jelly fungi are all examples of basidiomycetes, or club fungi. Club fungi gets its name from a specialized reproductive structure that resembles a club, and it is a spore-bearing structure called the basidium. Cup fungi are ascomycetes. In cup fungi, asci lie on the interior surface of the cup. At maturity, the spore-filled asci burst, releasing spores into the air.
An ecologist is studying an ecosystem. The community in the ecosystem consists of hundreds of different populations including the following species: field mouse, wheat, falcon, honey bee, white tailed deer, cotton tail rabbit, sunflower, and gray wolf. One summer, the ecologist observes a disease that spreads through the wolf population and kills off 80% of the wolves. Which of the following will be the least affected by the loss of the wolves? decomposers primary producers secondary consumers primary consumers
decomposers Decomposers are the least likely to be affected by the loss of the wolves. As long as something is dead, the decomposers will consume it.
Which of the following is the greatest threat to biodiversity today? pollution endangered species deforestation invasive species
deforestation The greatest of all threats to Earth's biodiversity is deforestation. While deforestation threatens ecosystems across the globe, it's particularly destructive to tropical rainforests. In terms of Earth's biodiversity, rainforests are hugely important; though they cover only 7 percent of the Earth, they house more than half the world's species. Through logging, mining and farming, humans destroy approximately 2 percent of the Earth's rainforests every year, often damaging the soil so badly in the process that the forest has a difficult time recovering.
Which of the following is a reaction that links together the monomers of a polymer? hydrolysis dehydration synthesis cellular respiration photosynthesis
dehydration synthesis Dehydration synthesis happens when monomers lose a water molecule in order to link together. Cellular respiration is the process of breaking down glucose, photosynthesis involves making glucose molecules, and hydrolysis is the opposite of dehydration synthesis, because it involves separating monomers by adding water.
A certain habitat has the following characteristics. Average daily high temperature of -5° C. Low species diversity and density. Low yearly rainfall. In which of the following biomes is the habitat located? desert taiga savanna tropical rain forest
desert Not all deserts are hot- the most important characteristic of a desert is dryness
Starfish use all except which of the following methods to reproduce? asexual reproduction fission fragmentation sexual reproduction
fission Starfish reproduce using fragmentation, asexually, and sexually.
A person standing near the top of a mountain will breathe faster in order to get more oxygen. Which of the following is likely to happen because of the increased breathing rate? - increased pH of blood - decreased pH of blood -increased carbon dioxide in the blood -decreased oxygen level in the blood
increased pH of the blood When the person breathes faster, he is taking in more oxygen and releasing more carbon dioxide into the air, so oxygen levels increase, and carbon dioxide levels decrease. When carbon dioxide levels in the blood decrease, the pH of the blood will increase.
Which of the following is the unit of selection according to Darwin's theory of evolution by natural selection? population species individual community
individual Natural selection is about how gene frequencies change in a population over time, but nature can't select individual genes. It can only select which individual organisms are suited to the environment and which are not. The fit individuals survive and reproduce, and the unfit ones die off.
A clown fish is taken from a saltwater tank and put into a freshwater tank. Shortly thereafter the clown fish dies. Which of the following describes what has happened to the clown fish? -diffusion - osmosis -thermodynamics -hydrolysis
osmosis Clown fish have extra salt in their cells to slow down the process of osmosis from the cells to the saltwater outside the cells. If you put the clown fish in a freshwater tank, the water is too hypotonic and osmosis will keep bringing water into the cell until the cell bursts and dies.
Which of the following leaf structures contains guard cells? upper epidermis layer palisade layer spongy mesophyll layer lower epidermis layer
ower epidermis layer The lower epidermis layer is a single layer of clear cells that contains stomates and guard cells. The upper epidermis layer is a single layer of clear cells that allows light to pass through and prevents the loss of water. The palisade layer contains long columnar cells that are packed tightly together. Palisade layer cells contain chloroplasts and are the main cells carrying out photosynthesis. The spongy mesophyll layer contains cells with chloroplasts and is a major site of photosynthesis.
The stomates of a leaf function in all of the following EXCEPT: photosynthesis respiration preventing loss of water excretion
preventing loss of water The stomate is an opening in the lower epidermis that allows carbon dioxide into the leaf and water and oxygen out of the leaf. The stomates of a leaf function in photosynthesis, respiration, transpiration, excretion, and evaporation. The cuticle and upper epidermis layer help prevent the loss of water.
Which process is the opposite of photosynthesis? transpiration respiration excretion evaporation
respiration In photosynthesis, light energy is converted to chemical energy and stored in the glucose molecule. In respiration, energy stored in the glucose molecule is released in the form of ATP. Transpiration is when water is lost through the stomates. Excretion happens when oxygen and carbon dioxide are released from the leaf through stomates.
All of the following are carried by the xylem EXCEPT: ammonia sugars minerals water
sugars Things that are soaked up by a plant's roots, such as minerals, water, and ammonia found in soil, are carried by the xylem and sent from the roots to the leaves. Sugars are produced in the leaves and carried to the rest of the plant through the phloem.
All of the following statements about offshore drilling are true EXCEPT: -it can release other toxic chemicals back into the ocean -seismic waves used to locate oil can harm sea mammals -the majority of oil spills are a result of drilling -transportation of oil from drills accounts for one-third of oil spills worldwide
the majority of oil spills are a result of drilling Drilling can harm the environment in numerous ways. Seismatic waves used to locate oil can harm sea mammals and disorient whales. Drilling release harmful substances like lead, arsenic, and mercury back into the ocean. Though oil spills from the drills themselves have decreased in recent years, the transportation of oil from the drills to land accounts for one-third of oil spills worldwide.
All of the following statements describe the multiplication strategies of retroviruses, such as HIV, EXCEPT: -they contain single-stranded RNA for genetic material -their RNA molecules can't be read directly to create proteins -the virus uses a unique enzyme called reverse transcriptase -the double-stranded DNA enters the nucleus, where it inserts into the host DNA by recombination
their RNA molecules can't be read directly to create proteins Retroviruses like HIV contain single-stranded RNA for their genetic matieral. Once this RNA enters the cytoplasm, the virus uses reverse transcriptase to make a DNA copy of the RNA. The double-stranded DNA enters the nucleus, where it inserts into the host DNA by recombination. Negative-sense viruses have RNA molecules that can't be read directly to create proteins, and include viruses such as influenza and measles.
All of the following is true about viruses EXCEPT: -they contain double-stranded RNA. -they contain single-stranded DNA. -they contain DNA and RNA. -they have an outer membrane layer
they contain DNA and RNA. A single viral particle can contain only DNA or RNA, and that includes: double-stranded DNA, single-stranded DNA, double-stranded RNA, and single-stranded RNA. Some viruses also have an outer membrane layer called an envelope.
All of the following about microtubules is true EXCEPT: - they help pinch animal cells in two during cell division -they are made of the protein tubulin -they are the proteins inside cilia and flagella -they act as railroad tracks for the movement of vesicles
they help pinch animal cells in two during cell division Microtubules are made of the protein tubulin, are the proteins inside of cilia and flagella, act as railroad tracks for the movement of vesicles and some organelles, and move chromosomes during cell division. Microfilaments are the proteins that help pinch animal cells in two during cell division.
Who was the first person to study living cells? Hooke Janssen Leeuwenhoek Darwin
van Leeuwenhoek Anton van Leeuwenhoek was the first to see living things such as bacteria and animal-like protists. Although Zacharias Janssen preceded Leeuwenhoek and made a compound microscope, he did not use it to study living things.
Which of the following plant structures is found in all roots, stems, and leaves? -lenticels -spongy mesophyll cells -vascular tissue -guard cells
vascular tissue Vascular tissue in vascular bundles forms the transportation network of the leaf, stem, and root. The phloem cells carry sugar and starch down to the roots for storage. The xylem cells carry water and minerals up from the roots. Guard cells and spongy mesophyll cells are founds in the leaves of plants, and lenticels are small openings in the stem that allow oxygen in and carbon dioxide out.
Which of the following are used to bring DNA into other cells? capsules enzymes pods vectors
vectors A vector is a carrier used to bring DNA into other cells. Viruses and bacterial plasmids are examples of commonly used vectors.
When water molds reproduce asexually, portions of the hyphae develop into which of the following? zoosporangia antheridium oogonium zygotes
zoosporangia When water molds reproduce asexually, portions of the hyphae develop into zoosporangia, which are spore cases. Each zoosporangium produces flagellated spores that swim away in search of food. When they find food, the spores develop into hyphae, which then grow into new organisms.