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- One of the adaptation necessary for the evolution of tall vascular plants was
- an effective water-conducting system
- Xylem and phloem are found in all land plants except
- mosses
- what is the main advantage of of a plant's having root hairs
- to increase the surface area of roots
- the purpose of a transport system is to
- carry nutrients to cells and waste products away from cells
- in order for land plants to obtain gases for photosynthesis and cell respiration, land plantrs mus have
- stomata
- the movement of water through xylem tissue
- is all passive transport
- plants with mycorrhizae on their roots systems
- have an enhanced method for obtaining nutrients
- which of the following explains how water and its dissolved nutrients reach the top of a 100-meter-tall tree
- the cohesion-tension hypothesis
- which of these is not a factor in the cohesion-tension theory
- root pressure
- the movement of food from the leavevs to the roots is explained by
- pressure-flow hypothesis
- to produce an upward movements of wat in xylem
- water must evaporate from the top
- according to the cohesion-tension theory of water transport, if a tall 100-meter-tall tree were to have water flow, it would require
- a continuous column of water 100 meters high
- what plant structures carries water
- xylem
- how does water escape from plants with xylem
- stomata in the leaves
- the phloem cell in stems transport
- food down to the roots
- an insect's digested nutrients are transported by
- an open circulatory system
- the concentraion of nutrients in the fluid traveleing away from the hear is different from the concentration in teh fluid returning to the heart. this statement is a reasonable description of
- a closed circulatory system
- hydras lack a special transport system and grasshoppers cannot survive without one, because
- diffusion can supply the cells of hydras with essential materials
- many capillaries are found
- throughout all organs
- the blood vessels through which oxygen rapidly diffuses are the
- capillaries
- in a four-chambered heart, separation of blood from the lungs and blood from the rest of the body increases efficiency of
- the exchange of oxygen and carbon dioxide between blood, body cells, and lungs
- an artery comes from the
- bottom right part of the heart
- ventricles are at the
- bottom of the heart
- a disadvantage of a three-chambered heart is that
- oxygenated and deoxygenated blood mix
- what maintains the heart's regular rhythm
- pacemaker
- the walls of arteries are more elastic and muscular than the walls of veins, which allows arteries to
- withstand the pressure of each blood surge from the heart
- which of theses is a characteristic of veins, not of arteries
- valves
- the hemoglobin of red blood cells greatly incereases the blood's
- oxygen-carrying capacity
- food molecules absorbed from the intestine of an animal are carried throughtout the body by
- the fluid of the circulatory system
- a person having a low red blood cell count will have fifficulty
- transporting oxygen to cells
- a doctor orders a blood test to check for abnormal chemicals in the blood. if present, in which part of the blood would the chemicals be found
- plasma
- the lymphatic systems gathers intercellulars fluid that was originally in teh
- capillaries
- lymph fluid contains
- white blood cells, water, and salts
- much of the fluid that leaks into bodytissues returns to the circulatory system via
- lymph vessels
- the elements in blood responsible for clotting are
- platelets
- the protein in blood taht forms a blood clot is
- fibrin
- which is not a function of the circulatory system
- releasing enzymes for food digestion
- the human circulatory system aids in maintaining homeostasis by
- transporting nutrients, wastes, and hormones
- in eukaryotic multicellular organisms, cell division serves all of these purposes except
- reproduction of new individuals
- when does a prokaryote's membrane pinch inward and divide the cell in two
- when the cellvolume has doubled
- prokaryotic cell dicision is referred to as
- binary fission
- which functions are served by cell division
- it allows surface area to keep up with growing volume of an organism, replaces cells that wear out or are damaged, produces many types of cells that serve a variety of functions
- eukaryotic cell division requires
- accurate replication and equal division of the genetic information encoded in the cell's DNA
- which of the following statements is true
- the cell cycle is similar in all eukaryotes
- the phase of the cell cycle involving sorting and distribution of chromosomes is
- M
- interphase is
- the period between cell divisions
- during G1 and G2, cell synthesize
- proteins, RNA, and other macromolecules
- the G0 phase of the cell cycle is
- a stopping point is G1
- adult cells that do not, or rarely, divide will be found primarily in what phase of the cellcycle
- G0
- using a light microscope, you can most easily recognize chromosomes in what phase of the cell cycle
- M
- division of the whole eukaryotic cell is called
- cytokinesis
- when a cell with 24 chromosomes during G1 phase divides by mitotic cell division, t he resulting offspring cells will each have a maximum chromosome number of
- 24
- after normal mitotic division, how many chromosomes does each offspring cell contain, as compared to the parent cell
- the same number
- in order for a substance to act as a carrier of hereditary information, it must be
- precisely copied during the cell cycle
- in eukaryotic cells, when does chromosome replication occur
- during interphase
- DNA is replicated during which phase of the cell cycle
- S
- adult nerve cells stay in the G0 phase, this means they
- do not divide
- a scientist was collecting data about the number of chromosomes that a certain organis had. most of the skin cells that he examined had a certain amount of chromosomal material, but he found some skin cells with double the chromosomal material. what migh
- some skin cells werer in the G2 phase
- a graduate student was told to use a light microscope to count the number of chromosomes in the cells of a newly discovered species. what phase of the cell cycle would the student have to investigate
- M
- the backbone of DNA in compose of
- sugars linked through phosphates
- synthesis of DNA
- involves enzymes that bind to the DNA
- watson and crick describeed the DNA molecule asa a
- double-stranded molecule
- how does the sequence of basaes on one strand of DNA control the sequence of bases on the second strand
- adenine on one strand can pair only with thymine on the oter strand; cytosine, only with guanine
- why does adenine paironly with thymine and cytosine only with guanine in a DNA molecule
- their molecular shape deterines how they are paired
- DNA polymerase is an enzyme that catalyzes the formation of new DNA strands. During what phase of the cell cycle would a researcher be able to investigate the activity of this enzyme
- S
- why are the new bases of the two DNA strands added in opposite directions during replication
- the DNA polymerases can work only in one direction
- the replication of a double-stranded DNA molecule begins when the strands separate at the
- hydrogen bonds between paired nulceotides
- histones are
- nuclear proteins
- what is the function of "proofreader" enzymes
- they identify and repair incoorect or damaged nucleotides
- Why is theDNA repair sequence important to an organism's survival
- it reduces the number of mutations that are copied
- mutations
- involve any change in the sequence of a cell's DNA
- which molecule acts as proofreader during dNA replication
- DNA polymerase
- structures that hold sister chromatids together in double-stranded chromosomes are known as
- centromeres
- each strand of double-stranded chromosome is known as a
- chromatid
- a cell with 8 chomosomes before mitosis will produce new cells that have
- 8 chromosomes
- the process of mitosis ensures
- euqal division of nuclear material
- in mitosis, breakdwon of the nuclear membrane occurs in
- prophase
- a mitotic spindle is formed from
- microtubules
- in mitotosis, separation of sister chromatids occurs during
- anaphase
- prograssion trhough teh cell cycle is regulated by
- cyclins
- a gemete contains
- a half set of chromosomes
- a sygote begins to develop jst after
- fertilization
- the fertilized egg is a single cell that contains
- chromosomes from both egg and sperm
- the multiple rounds of mitosis that produce many small cells is called
- cleavage
- by the end of cleavage, the embryo consists of a mass of cells called
- blastula
- the inner lining of the digestive system forms from this (these) tissue layer(s)
- endoderm
- your skin and nails form from this (these) tissue layer(s)
- ectoderm
- mesoderm tissues were placed in a dish with saline solution for 3 hours. the mesoderm was removed, and ectoderm tissues were placed in the dish. Ectoderm was also placed in a second dish containing saline solution. what hypothesis was being tested?
- mesoderm may produce a chemical that induces ectoderm to differentiate
- this stiff rod that runs down the middle of the embryo that will become a part of the backbone is called the
- notochord
- a tadpole transforms into a frog through a process caled
- metamorphosis
- these cells are specialized for transporting oxygen
- red blood cells
- these cells contain a major protein called keratin
- skin cells
- these cells contain a major protein called hemoglobin
- red blood cells
- the three layers that make up the gastrula are called
- primary germ layers
- sex cells, such as the sperm in males and the egg in females, are also called
- gametes
- the blastula forms during this stage
- cell division
- muscle cells, nerve cells, and skin cells result from this process
- cell determination
- cleavage of the fertilized egg occurs during this process
- cell division
- this process noticeable begins at the gastrula stage
- cell determination
- an energy-rich collection of lipids and proteins in the cytoplasm of the egg is called the
- yolk
- as cells differentiate, they organize to form the tissues and organs of complete animals in a process called
- morphogenesis
- the major changes during the development of a blastula into a gastrula are called
- gastrulation
- which of the following processes gererates shape and form in an embryo
- morphogenesis
- the union of sperm and egg is called
- fertilization
- in mammals, nutrients, wastes, oxygen, and carbon dioxide are exchanged between mother and embryo by the
- placenta
- mammal embryos are attached to the placenta by the
- umbilical cord
- in vertebrates, accidental separation of the two cells that are formed during cleavage results in
- identical twins
- one organ can be transformed into another due to errors in
- homeotic genes
- the hypothesis that states that all cells contain the same genes is the
- genetic-equivalence hypotesis
- a human embryo does not contain a
- large supply of stored food
- an experiment where the nucleus of an unfertilized egg is replaced with the nucleus of a differentiated cell could demonstrate
- how much the nucleus controls cell development
- to clone sheep, ian wilmut and his colleagues replaced the nucleus of a sheep's egg with the nucleus of a cell from
- a female sheep's udder
- the cloning of a sheep in 1996 was an important experimental result, supporting the
- genetic-equivalence hypothesis
- genes act by directing the synthesis of
- proteins
- which of teh following statements is true
- gene expression is controlled differently in specific cell types
- dna and rna are
- nucleic acids
- dna controls protein synthesis by
- encoding amino acid sequence
- dna controls teh tertiary structure of proteins because dna is directly responsible for
- transcription of rna and amino-acid sequence
- proteins are synthesized from less complex organic molecules known as
- amino acids
- mRNA carries the genetic code of dna because
- the mRNA has a sequence exactly complementary to the dna
- amino acids are required in the human diet principally for the synthesis of
- proteins
- which group of organic compounds includes enzymes
- proteins
- which of the following is not representatice of known types of RNA molecules
- previous RNA (pRNA)
- the sequence of nucleotides in a messenger rna molecule (mRNA) is determined by the sequence
- dna molecule
- the ribosomes of the cell are sites for the synthesis of
- proteins
- in a cell the transfer of genetic information from dna to rna occurs in the
- nucleus
- dna in the nucleus controls the activities in the rest of the cell by serving as a blueprint for
- enzymes
- one type contains instruction for protein synthesis
- nucleic acids
- one type is the carrier of hereditary information
- nucleic acids
- which compound is used primarily as a source of stored energy
- none of the above
- the dna code for an amino acid consists of a sequence of
- 3 nitrogen bases taken from 4 possible bases
- how did scientists determine that using single and double nitrogen bases for the codes for amino acids would not be sufficient
- scientists knew that there were 20 different amino acids and therefore at least three bases were needed
- which molecules are chains of nucleotides
- both dna and rna molecules
- which molecules contain uracil
- rna molecules
- which molecules contain cytosine
- both dna and rna molecules
- which molecules contain ribose
- rna molecules
- which molecules control hereditary instructions in animals, plants, and most protists
- dna molecules
- which molecules are assumed to be a double helix
- dna molecules
- which molecules are found in three different forms in any given cell
- rna molecules
- whcih molecules are composed of a specific amino acid sequence
- neithe rdna nor rna molecules
- gene expression begins with
- rna synthesis
- the enzyme that initiates the first stage of transcription is
- rna polymerase
- which series is arranged in correct order according to decreasing size of structures
- nucleus, chromosome, dna, nucleotide
- the specific protein produced in a cell is directly related to the
- nucleotide sequence in the dna molecule
- why is the rna in the cyosol much smaller than the rna in the nucleus
- noncoding regions of rna are removed in the nucleus
- the function of tRNA molecules is to
- transport amino acids to mRNA
- the production of proteins is directed by the dna because it is the template for
- mRNA
- which of teh following carries amino acids to the site of protein synthesis
- transfer RNA oly
- where does translation take place
- ribosomes
- viruses
- replicate, but are not considered to be alive
- in general, viral replication involves
- production of viral proteins and assembly of viral particles within a hsot cell
- gemes are sequences of nucleotides that may code for
- polypeptides, proteins, tRNA, and mRNA
- each paraent contributes one of two genes for a particular trait. the gene pairs are called
- alleles
- a eukaryotic chromosome is a
- long molecule of DNA, some of which is never translated
- the Pace family has seven children, one son and six daughters. what is the chance that the eighth child will be a daughter
- 1/2
- what is the chance, if a couple has two children, that they will have on boy and one firl
- 1/2
- a coin is tossed three times. the probablility that it will alnd heads up all three times is
- 1/8
- a tossed coin lands heads up six times straight. what is the probablility that it will lands tails up on the secenth toss
- 50%
- two coins are tossed together 40 times. approximately how many times should both lands tails up
- 10
- in mating pea plants with yellow pods and pea plants with green pods. Mendel found the f1 offspring produced only green pods. Mendel suggested that the yellow trait
- is not express when its factor is present in combination with the green factor
- a trait is not visible in teh f1 generation but reappears unchanged in the f2 generation is
- recessive
- during gamete formation in a diploid organism
- alleles separate from one another
- mendel's principle of segragation refers to the
- separation of alleles for a particular trait during gamete formation
- which step in meiosis corresponds to Mendel's principle of segragation
- separation of homologoues chromosomes
- what type of gametes can be produced by a pea plant with green pods and round seeds (genotype GGRr)
- GR, Gr
- what type of gametes can be produced bya pea plant that is tall with yellow seeds (genotype TtYy)
- TY, Ty, tY, ty
- if three quarters of the offspring from many experimental crosses showed only teh dominant traits, the parents were
- both heterozygous
- the gene for rough coat (R) is dominant to smooth coat (r) in in a guinea pig. if a smoth coated guinea pig was bred to a roughcoated guinea pig and had seven smoothcoated and eith roughcoated offspring, what are the genotypes of the parents.
- one parent is homozygous recessive, and the other parent is heterozygous
- the gene for rough coat (R) is dominant to smooth coat (r) in in a guinea pig. if a smoth coated guinea pig was bred to a roughcoated guinea pig and had seven smoothcoated and eith roughcoated offspring, what are the genotypes of the roughcoated offsprin
- Rr
- the genetic makeup of an organism for aparticular trait
- is determined by the genotype
- the genotypes that cannot be dtermined by inspecting the phenotypes of the offspring of a cross are
- homozygous dominant and heterozygous dominant
- if homozygous redflowered plants crossed with white flowered platns proc=dcued all red flowered offspring, the gene for red florers must have been
- dominant
- genetic traits of seeds are noted as follows: G = long, W = wrinkled, Y = yellow, R = ribbed, g = short, w = smooth, y = white, r = grooved. which of the following is a possible genotype for a short, wrinkled, yellow, grooved seed
- ggWwYYrr
- two animals with the Aa genotype had one offspring. its genotyupe was aa. what is the probability that heir next offspring will have the genotype aa?
- 1/4
- if two offspring result from the cross Aa x Aa, what is the probablility that both offspring will havet the genotype aa?
- 1/16
- a certain dominant gene is located on the X chromosome. a father will transmit the gene and the resultin condition to
- all hist daughters
- if a decective gene is on the X chromosome, transmission to a female can be
- either from the mother or fromthe father
- if a defective gene is on the X chromosome, transmission to a male can be
- only from his mother
- in 1988, a florida couple chared a hospital with baby swapping, claiming that the baby they brought home was not their biological daughter. the father and the baby had type B blood, the mother type O. in terms of blood type, could the baby have belonged
- yes, the baby could have BO genotype.
- can a person with type a blood safely receive a transfusion of type O blod
- yes, there are no A and B surface proteins on the type O blood cells
- when the two bell shaped swash plants are crossed, 25% of the offspring are round, 25% oblong, and 50% in between, or bellshaped. this cross illustrates
- codominance
- the failure of homologous chromosomes to separate during meiosis is called
- nondisjunction