Biology Weeks 13-16

the disruption of which cell function leads to gene mutations that result in cancer? a. DNA replication b. RNA transcription c. RNA translation d. protein synthesis

a. DNA replication

the Tasmanian devil has 14 chromosomes in each of its somatic cells, 2n = 14. how many chromosomes would be present in a cell after anaphase of mitosis? a. 7 b. 14 c. 21 d. 28

d. 28

a trichoplax is a simple multi-cellular animal that lives in water. this animal can reproduce asexually by simply dividing into two organisms. Part A: identify and describe a cellular division process that could be used by trichoplax when it reproduces asexually Part B: describe one benefit and one limitation of how the trichoplax can reproduce by simply dividing

Part A: a cellular division process that could be used by trichoplax when it reproduces asexually is binary fission. binary fission is when an organism replicates yourself and its DNA, and then it divides into 2 separate organisms. Part B: one benefit is that it can reproduce by itself and it can make the population grow quickly. one limitation is that it cannot gain any genetic variation that may help the organism if the environment around them changes.

the cell cycle is regulated by both external and internal factors. Part A: list two external factors that influence the cell cycle and briefly describe them Part B: list two internal factors that influence the cell cycle and briefly describe them

Part A: external factors that influence the cell cycle can include physical and chemical factors. a physical example is when one cell touches another cell, it sends a signal that makes the cell stop dividing. a chemical example is growth factors. growth factors are proteins that stimulate cell division Part B: one internal factor that influences the cell cycle is genetics. depending on an organisms genetics, there may be more cell division in one organism than another. another internal factor is nutrients. nutrients can help cells divide and keep cells in an organism healthy

compare and contrast the processes of mitosis and meiosis. Part A: describe two processes that occur in both mitosis and meiosis Part B: think about the cells at the outcome of both processes. how are they different? explain at least two differences

Part A: one process that occurs in both is prophase. during this, the nuclear envelope dissolves and chromosomes condense. another process that occurs in both is anaphase. during this, homologous pairs separate and are pulled to opposite sides Part B: mitosis cells have the same amount of chromosomes that the mother cell has, but in meiosis, the cells have half the number. mitosis produces 2 daughter cells, and meiosis produces gametes

nondisjunction during meiosis results in an abnormal number of chromosomes in one or more gametes. in some cases of nondisjunction, a single chromosome fails to separate. in others, none of the chromosomes separate. suppose an egg is produced in which none of the chromosomes separate during meiosis 2. what is the chromosome number of the zygote that results if this egg is fertilized by a normal sperm? a. 3n b. 2n + 1 c. 1n d. 2n

a. 3n

which factor BEST explains how many diseases, such as cancer, are formed within the body? a. a disruption in the cell cycle has taken place b. a mutation occurred during the process of crossing over c. a response by the immune system was triggered by an allergic reaction d. a traumatic injury to the body has occurred

a. a disruption in the cell cycle has taken place

devil facial tumor disease (DFTD) is a disease that is decimating the population of Tasmanian devils. the disease passes from one animal to another through bites and is caused by parasites. the parasites cause cancerous tumors that spread throughout an infected animal's body and kill it. what is the BEST description of DFTD? a. an infectious, cell-cycle disease b. a non-infectious, chronic disease c. a non-infectious, cell-cycle disease d. an infectious, chronic disease

a. an infectious, cell-cycle disease

in a developing embryo, what process allows cells of the mesoderm to give rise to muscle, bone, and heart tissues? a. cell differentiation b. cellular replication c. cellular respiration d. cell depolarization

a. cell differentiation

during the time of normal cell activity, DNA exists in a loose, spaghetti-like form called _______ a. chromatin b. centromere c. histone d. chromosomes

a. chromatin

at the end of meiosis 2, what is the end result? a. four unique haploid cells d. four identical haploid cells c. two genetically identical daughter cells d. two genetically different daughter cells

a. four unique haploid cells

a section of the chromosome that codes for a particular trait is called a a. gene b. chromatin c. histone d. base pair

a. gene

which characteristic of life is best illustrated by the equation below? seed ---> seedling ---> young tree ---> mature tree a. grow and develop b. need energy c. maintain homeostasis d. respond to stimuli

a. grow and develop

which of the following statements best explains the role of meiosis in reproduction? a. meiosis makes it possible for a zygote to have the correct number of chromosomes b. meiosis results in offspring with genotypes that are not exact copies of the parents c. meiosis allows chromosomes to exchange genetic material through crossing over d. meiosis increases the chances of fertilization because it produces four daughter cells

a. meiosis makes it possible for a zygote to have the correct number of chromosomes

which statement describes one difference between mitosis and meiosis in animal cells? a. mitosis produces two daughter cells, and meiosis produces four daughter cells b. mitosis produces sex cells, and meiosis produces diploid cells c. mitosis produces haploid cells, and meiosis produces somatic cells d. mitosis produces four daughter cells, and meiosis produces two diploid cells

a. mitosis produces two daughter cells, and meiosis produces four daughter cells

which of the following is a result of the exchange of homologous chromosome parts during the process of meiosis? a. offspring with unique combinations of traits b. decreased gamete number c. random mutations d. decreased number of alleles on each chromosome

a. offspring with unique combinations of traits

statement 1: all living things are composed of cells statement 2: if soil contains high levels of salt, the plants will die statement 3: the temperature reading on the thermometer is 21 degrees Celsius statement 4: it must have rained this morning because the soil is wet A teacher lists 4 statements for students to interpret. which piece of information correctly distinguishes between the statements? a. s1: theory, s2: hypothesis, s3: observation, s4: inference b. s1: observation, s2: inference, s3: fact, s4: hypothesis c. s1: fact, s2: theory, s3: hypothesis, s4: observation d. s1: inference, s2: observation, s3: theory, s4: fact

a. s1: theory, s2: hypothesis, s3: observation, s4: inference

after DNA replication during S phase of interphase, each chromosome has a copy and the cell is now 4n. we call these identical pairs ______ and they are held together by a _________ a. sister chromatids; centromere b. homologous pairs; centrosome c. sister chromatids; histone d. homologous pairs; histone

a. sister chromatids; centromere

banking stem cells is a very popular practice in science. this is when stem cells, located in the umbilical cord of a birthed infant, are saved and frozen. why could this be a beneficial practice? a. stem cells are undifferentiated and therefore, could be used to grow into any kind of cell of the body b. stem cells should not be saved because all cells of the body can be used as stem cells c. stem cells are already differentiated but can still replace different cells located in the body d. in case of an emergency, it is always good to have a lot of cells on hand since they cannot replace themselves

a. stem cells are undifferentiated and therefore, could be used to grow into any kind of cell of the body

after observing the F2 generation, what conclusion did Mendel come to? a. the recessive trait reappeared about 25% of the time b. there appeared to be a blending, or intermediate, of traits in the F2 generation c. none of the above are correct d. the recessive trait had disappeared in the F2 offspring

a. the recessive trait reappeared about 25% of the time

genetics and the environment both play roles in cell differentiation. which is the BEST example of an environmental factor influencing cell differentiation? a. the terminal bud on a runner of a strawberry plant begins growing roots when it contacts the ground b. cambium cells in the trunk of an apple tree form rings of xylem and phloem annually c. the cells of a chicken embryo divide to form three layers: the ectoderm, mesoderm, and endoderm d. during meiosis, a single cell divides to form four gametes with half the number of chromosomes that somatic cells have

a. the terminal bud on a runner of a strawberry plant begins growing roots when it contacts the ground

Mendel came up with his Law of Independent Assortment through his investigations studying a. whether or not the inheritance of one trait affected the other b. the passing down of dominant seed shape to offspring c. how self-pollination affects the second filial generation d. simple monohybrid traits such as plant height

a. whether or not the inheritance of one trait affected the other

a certain organism has 24 pairs of homologous chromosomes (n = 24). how many chromosomes will each daughter cell have after telophase 2 of meiosis? a. 12 b. 24 c. 48 d. 54

b. 24

Mendel concluded that sexually reproducing organisms contribute only one copy of each factor to each of their egg or sperm cells. this was the basis for his a. Law of Independent Assortment, because the male copies of a trait must go to the sperm cells and the female copies to the eggs b. Law of Segregation, because individuals have 2 forms for each trait and they must separate during the formation of eggs and sperm c. Law of Independent Assortment, because Mendel was responsible for the pollination of each plant physically and that altered the genes in each sex cell d. Law of Segregation, because the two forms of each trait must come together to create a blending of the two in each offspring

b. Law of Segregation, because individuals have 2 forms for each trait and they must separate during the formation of eggs and sperm

which of the following experimental conditions ensured that Mendel would get accurate results in his experiments on pea plants? a. he used true-breeding, or "pure bred" plants b. all of the above c. he physically controlled the breeding of the plants d. he observed only traits that had two forms, such as "tall" and "short"

b. all of the above

how are binary fission and mitosis similar? a. the resulting daughter cells in both processes are genetically unique b. both processes produce genetically identical daughter cells c. the stages in both processes are identical d. both processes are used to create egg and sperm cells

b. both processes produce genetically identical daughter cells

life functions are performed at many levels of biological organization. which level of biological organization is the simplest level at which a structure can support life functions? a. organ system b. cell c. tissue d. organ

b. cell

there are several major structural differences between plant and animal cells. the presence of which structure in a plant cell makes cytokinesis more challenging? a. chloroplast b. cell wall c. centrioles d. Golgi apparatus

b. cell wall

to increase genetic diversity in offspring, homologous pairs ________ in prophase 1, and ________ in anaphase 1 a. randomly separate; cross over b. cross over; randomly separate

b. cross over; randomly separate

meiosis contributes to the process of reproduction by producing what type of cell? a. diploid b. haploid c. aneuploid d. polyploid

b. haploid

in which of the following cases would asexual reproduction be most advantageous for an organism? a. when new organisms are moving into and out of the population b. living in a stable environment with little variation c. when the need for adaptation is great d. living where there are many available partners

b. living in a stable environment with little variation

mitosis and meiosis are processes by which animal and plant cells divide. which statement best describes a difference between mitosis and meiosis? a. mitosis occurs only in eukaryotic cells b. mitosis produces genetically identical daughter cells c. meiosis is a multi-step process d. meiosis is used in the repair of an organism

b. mitosis produces genetically identical daughter cells

a woman has been diagnosed with melanoma, a skin cancer that develops in fully differentiated skin cells called malanocytes. she is concerned that the skin cancer risk could be transferred to her future offspring. should she be concerned about this? a. no, because her treatment will be completed before she attempts to have children b. no, because skin cancer has occurred in her somatic cells, not her gametes c. yes, because skin cancer has become part of her somatic cell make-up d. yes, because skin cancer cells would be present in the developing offspring

b. no, because skin cancer has occurred in her somatic cells, not her gametes

the function of which human organ is most like the cell walls of bacteria? a. liver b. skin c. pancreas d. heart

b. skin

blood cells are different than nerve cells in how they look and what they do. why is this, since both of these kinds of cells are found in humans? a. blood cells undergo apoptosis in order to fulfill their role in the body b. the cells have differentiated to perform different tasks within the organism c. if blood cells were long like nerve cells they would get stuck in the blood vessels d. blood cells started out as nerve cells but changed shape due to their location

b. the cells have differentiated to perform different tasks within the organism

which of the following events in meiosis 1 does not contribute to the genetic diversity of the daughter cells? a. the blending of maternal and paternal chromosomes in the same gamete b. the cleavage furrow in the cell during telophase 1 c. random lining up of homologous chromosomes in metaphase 1 d. crossing-over in prophase 1

b. the cleavage furrow in the cell during telophase 1

which one of the following is NOT a reason for cell reproduction? a. reproducing organisms b. tumor suppression c. growing new cells d. repairing damaged cells

b. tumor suppression

in domestic cats, each somatic cell has 38 chromosomes. how many chromosomes would be found in the egg of a female domestic cat? a. 76 b. 38 c. 19 d. 8

c. 19

which is MOST likely a cancer treatment? a. a drug that kills only slowly dividing cells b. a drug that kills only very small cells c. a drug that kills only rapidly dividing cells d. a drug that kills only very large cells

c. a drug that kills only rapidly dividing cells

which statement best describes how antibiotics affect cellular homeostasis? a. antibiotics increase the rate of DNA replication in human cells by forming nucleotides b. antibiotics decrease the rate of cellular respiration in animal cells by producing oxygen c. antibiotics interfere with the transport of intracellular and extracellular materials d. antibiotics remove chloroplasts from plant cells to cause starvation

c. antibiotics interfere with the transport of intracellular and extracellular materials

which of the following does not increase genetic variation in a species? a. random fertilization b. crossing over c. binary fission d. independent assortment

c. binary fission

which statement is true for all prokaryotic and eukaryotic organisms? a. both types of organisms are made of cells, tissues, and organs that work together b. both types of organisms have DNA contained within a nucleus as genetic material c. both types of organisms assemble proteins through transcription and translation d. both types of organisms transform energy from sunlight into chemical energy

c. both types of organisms assemble proteins through transcription and translation

in plant cells, cytokinesis is completed by the formation of a(n) a. spindle b. equatorial plate c. cell plate d. membrane furrow

c. cell plate

which of the following statements is incorrect? a. ectoderm becomes outer skin and spinal cord b. endoderm becomes internal organs c. endoderm becomes bones and muscles d. mesoderm becomes bones, muscle, and kidneys

c. endoderm becomes bones and muscles

embryonic stem cells are pluripotent because they can a. grow into any type of body cell b. grow into similar types of cells such as blood cells to blood cells c. grow into any type of body cell, but they cannot become totipotent

c. grow into any type of body cell, but they cannot become totipotent

crossing over is the process whereby a. homologous chromosomes pair along their lengths b. homologous pairs of chromosomes separate and migrate toward a pole c. homologous chromosomes exchange chromosomal material d. sister chromatids pair at the centromeres

c. homologous chromosomes exchange chromosomal material

in a population, purple flowers are dominant over blue flowers. determine which statement below is NOT correct a. purple flowers must be either Pp or PP b. blue flowers must contain two recessive alleles c. it is more of an advantage to the purple flower to be homozygous dominant d. purple flowers and blue flowers can both be homozygous

c. it is more of an advantage to the purple flower to be homozygous dominant

which BEST explains why DNA replication in the human body is significant? a. it is necessary for protein synthesis b. it replaces any damaged DNA cells c. it is needed for cell division d. it produces RNA strands

c. it is needed for cell division

DNA is a nucleic acid. the monomer of a nucleic acid is a a. simple sugar b. amino acids c. nucleotide d. glycerol

c. nucleotide

meiosis is a type of cell division in which germ cells divide to produce haploid cells. where does meiosis occur? a. brain cells b. muscle cells c. ovary cells d. bone cells

c. ovary cells

which statement best explains why cellular respiration in plants and other organisms is dependent on photosynthesis? a. photosynthesis is one of the final steps in cellular respiration b. photosynthesis absorbs materials that are catalyzed during cellular respiration c. photosynthesis provides the materials that fuel cellular respiration d. photosynthesis absorbs excess energy produced by cellular respiration

c. photosynthesis provides the materials that fuel cellular respiration

which of the following statements lists the steps that occur in the cell cycle, in chronological order? a. sister chromatids are pulled apart to opposite ends of the cell; spindle fibers begin to appear b. nuclear membrane disappears; chromatin condenses c. sister chromatids align in the middle; cytoplasm pinches in to separate daughter cells d. centrioles move to opposite ends of the cell; cell passes through G1 checkpoint

c. sister chromatids align in the middle; cytoplasm pinches in to separate daughter cells

homologous chromosomes differ from sister chromatids because a. sister chromatids cannot be separated from one another, while homologous chromosomes can b. homologous chromosomes are identical copies, while sister chromatids are only similar in gene location c. sister chromatids are identical copies, while homologous chromosomes may differ in the allele present d. homologous chromosomes are formed after replication, while sister chromatids exist prior to S phase of interphase

c. sister chromatids are identical copies, while homologous chromosomes may differ in the allele present

most of the nucleated cells in a multi-cellular organism contain all of the genetic information for the organism. which of the following cells does not fall into this category? a. nerve cell b. parenchymal cell c. sperm cell d. epithelial cell

c. sperm cell

during which phase of meiosis does the separation of homologous chromosomes occur? a. prophase b. telophase c. metaphase d. anaphase

d. anaphase

myosin is plentiful in muscle cells, but is not found at all in lens cells. lens cells contain large amounts of crystallins, which are not found in muscle cells. why do some proteins appear in one type of cell but not in another? a. differentiated cells release unused proteins into the blood for other cells to use b. during differentiation, certain genes are added to cells to produce proteins that enable specific functions c. differentiated cells produce all proteins but destroy the proteins they do not use d. during differentiation, certain genes are activated to produce proteins that enable specific functions

d. during differentiation, certain genes are activated to produce proteins that enable specific functions

meiosis is necessary for which reproductive event to occur? a. binary fission b. cloning c. vegetative budding d. fertilization

d. fertilization

why is approximately 50% of any individual's DNA inherited from that individual's father? a. it was passed to the individual by a somatic cell from the father b. half of the individual's nuclei descend from the nucleus of the father's gamete c. half of the individual's cells descend from the father's gamete d. it was passed to the individual by a gamete from the father

d. it was passed to the individual by a gamete from the father

which function is accomplished by the formation of a haploid cell in sexually reproducing organisms? a. deletion of genetic material that has mutated b. production of offspring with identical chromosomal combinations from both parents c. elimination of genes that selection pressures are acting against d. production of a zygote with a complete set of chromosomes with genetic material from two parents

d. production of a zygote with a complete set of chromosomes with genetic material from two parents

if a cell is exposed to a chemical that inhibits the production of spindle fibers as the cell is preparing for mitosis, what would most likely happen? a. the cell would undergo meiotic division b. the cell would break open c. the cell would continue with mitotic division d. the cell would not divide

d. the cell would not divide

you are a doctor treating a patient who has recently experienced paralysis in his lower body. he asks you to give him more information about the use of adult stem cells and embryonic stem cells as possible treatments. in your explanation, you must use the words "pluripotent" and "multipotent". you should also list two advantages and two disadvantages of each.

embryonic stem cells are pluripotent, meaning they can become all cell types in the body. adult stem cells are more limited than embryonic cells, and they are multi-potent because they can become more than one type of cell. advantages of embryonic stem cells are they can originate almost all types of cells in the body, and they can grow easily in culture. disadvantages of embryonic stem cells are they are obtained from human embryos which means that they are destroyed during the process, and we still don't have enough information to understand these cells totally. advantages of adult stem cells are that if they come from a specific person and then are reintroduced in that person again, they are less likely to reject the person after the treatment, and they are present in a lot of organs and tissues. disadvantages of adult stem cells are that they are difficult to isolate, and they are not easy to have in a large amount, which is bad because you need them in large quantities for the treatment.