BIO 106 EXAM 3
If a cell contains 12 chromosomes at the end of meiosis I, how many chromosomes will the daughter cells contain at the end of meiosis II? A) 12 B) 6 C) 24 D) 3
A) 12
If a woman is a carrier for the X-linked color-blind recessive allele and her husband is normal, what are their chances that a son will be color-blind? A) 50% since the mother is the only carrier B) 25% because the mother is a hybrid C) none since he will also be just a carrier D) none since the father is norma; E) 100% because the mother has the gene
A) 50% since the mother is the only carrier
Women with X-linked disorders always pass the genes for the disorder to _________, while men with X-linked disorders always pass the genes for the disorder to ________. A) both their daughters and sons, only their daughters B) both their daughters and sons, only their sons C) only their daughters, only their daughters D) both their daughters and sons, their daughters and sons
A) both their daughters and sons, only their daughters
Pleiotropy typically A) causes various symptoms to appear even though it only impacts a single gene B) causes various symptoms to appear even though it only impacts multiple genes C) causes a single symptom to appear even though it only impacts multiple genes D) causes a single symptom to appear even though it only impacts a single gene
A) causes various symptoms to appear even though it only impacts a single gene
Virtually all specialized cells of multicellular organism A) have the same amount of DNA and the same number of chromosomes as all other cells of the organism and develop from the same basic stem cells B) contain more genetic material than less specialized cells of the same organism C) contain less genetic material than less specialized cells of the same organism D) develop through mutation from less specialized cells of the organism
A) have the same amount of DNA and the same number of chromosomes as all other cells of the organism and develop from the same basic stem cells
During which stage of meiosis does crossing-over occur? A) prophase I of meiosis I B) telophase I of meiosis I C) anaphase I of meiosis II D) prophase II of meiosis II E) anaphase II of meiosis I
A) prophase I of meiosis I
The cell formed through fertilization of an egg by a sperm is called a/an A) zygote B) gamete C) sperm cell D) ovum E) egg cell
A) zygote
If a parent has 48 chromosomes, how many chromosomes will each daughter cell have after mitosis and cytokinesis occurs? A) 12 chromosomes B) 48 chromosomes C) 96 chromosomes D) 24 chromosomes
B) 48 chromosomes
Which allele combination represents a homozygous dominant individual? A) Aa B) AA C) aa D) none of these are homozygous dominant individuals
B) AA
If an individual with a dominant phenotype is crossed with an individual with a recessive phenotype, 4 of their 9 offspring show the recessive phenotype. What is the genotype of the first parent? A) AA B) Aa C) aa D) the answer cannot be determined from this information
B) Aa
In a classic Mendelian monohybrid cross between a homozygous dominant parent and a homozygous recessive parent, which generation is always completely heterozygous? A) P generation B) F1 generation C) F3 generation D) F2 generation
B) F1 generation
Which is NOT true about daughter cells of mitosis or meiosis? A) In meiosis, daughter cells are haploid B) In meiosis, the daughter cells are genetically identical C) In mitosis, the daughter cells are genetically identical D) in meiosis, there are four daughter cells E) in mitosis, there are two daughter cells
B) In meiosis, the daughter cells are genetically identical
Homologous chromosomes are similar in all of these characteristics EXCEPT A) carry genes for the same traits B) carry the same alleles for all traits C) similar in shape and location of centromere D) similar in size
B) carry the same alleles for all traits
Which of the following steps would NOT lead to variation of genetic material? the random alignment of the chromosomes during metaphase I B) crossing over of sister chromatids C) crossing over of homologous chromosomes D) the combination of sperm and egg genes
B) crossing over of sister chromatids
A change in the chromosome number resulting from nondisjunction is called euploid A) true B) false
B) false
Since each child of two heterozygous parents has a 50% chance of receiving a recessive trait from each parent, A) if the first child is phenotypically recessive, then the next child must be phenotypically dominant B) no matter what the first child's phenotype, the next child will have a 1/4 chance of being phenotypically recessive C) if the first child is phenotypically recessive, then the next child has a 3/4 chance of being phenotypically recessive D) if the first child is phenotypically recessive, then the next child has a 1/2 chance of being phenotypically recessive
B) no matter what the first child's phenotype, the next child will have a 1/4 chance of being phenotypically recessive
Haiti is settled by peoples of both African and European ancenstry. A young couple, both with mixed ancestry, marry and have several children. The children vary widely in the amount of skin melanin production, with one child being lighter than both parents, and one being darker. The simple explanation for this is A) multiple alleles are available for the one chromosomal locus that governs skin color B) polygenic inheritance C) epistasis D) gene linkage E) the environment affected the phenotype that developed
B) polygenic inheritance
If a sperm cell contains 23 chromosomes, it comes from an animal that has ____ chromosomes. A) 12 B) 23 C) 46 D) 92 E) 32
C) 46
Which is NOT true about the chromosomes of a multicellular organism? A) all cells contain chromosomes that carry the same genetic information B) they are made up of DNA and protein C) Each chromosome separates into two daughter chromosomes by binary fission D) each chromosome is replicated into two chromatids during the S phase of interphase
C) Each chromosome separates into two daughter chromosomes by binary fission
In some organisms, mitosis occurs without cytokinesis This results in A) uncontrolled cell division B) cells arrested in the G0 phase C) a multinucleate cell D) cell death E) cells with no nucleus
C) a multinucleate cell
The polar body is A) the cell produced when fertilization occurs B) a precursor cell that becomes an egg cell C) a nonfunctional cell rudiment formed at the same time as an egg cell D) another name for an egg cell
C) a nonfunctional cell rudiment formed at the same time as an egg cell
The pedigree chart depicts the inheritance pattern of _______. Circles depict females and squares depict males. Colored shapes represent affected individuals (expressing a trait) and uncolored shapes are unaffected (do not express a trait) A) an autosomal recessive characteristic with both parents being homozygous B) none C) an autosomal recessive characteristic with both parents being heterozygous D) an autosomal dominant characteristic with both parents being homozygous dominant
C) an autosomal recessive characteristic with both parents being heterozygous
The overall function of meiosis includes all of the following EXCEPT A) reduction of chromosome number (from 2N to N) B) providing genetic variation in sexually reproducing organisms C) growth of the overall individual D) gamete production
C) growth of the overall individual
During ______ the homologous chromosome pairs separate in a random fashion leading to genetic diversity among the offspring A) mitosis B) anaphase II C) independent assortment D) metaphase
C) independent assortment
Below the skin are "stem cells" that divide, with some cells continuing the stem cell line and others being pushed toward the surface to flatten and die and be sloughed off. In the bone marrow other stem cells produce erythrocytes that lose their nucleus and function for a few months in the bloodstream before they too die. Such "dead end" cells that reproduce no further A) halt in the midst of the S phase B) reverse from G2 to G1 C) leave the cell cycle in a G0 phase, which immediately follows telophase D) leave the cell cycle in a G3 phase, which immediately follows G2 E) continually cycle but simply fail to go through cytokinesis
C) leave the cell cycle in a G0 phase, which immediately follows telophase
Which statement is NOT true about eukaryotic chromosomes? A) chromosomes condense from chromatin at the start of mitosis B) chromosomes contain both DNA and associated histones C) there is only one chromosome of each type in each body cell D) chromosomes disperse back into chromatin at the end of mitosis E) chromosomes are not located within the nuclear envelope during mitosis
C) there is only one chromosome of each type in each body cell
Interphase: A) results in an increase in cell size B) includes G1, S, and G2 stages C) occupies the majority of the cell cycle D) all of the answer choices are correct E) none of the answer choices are correct
D) all of the answer choices are correct
Apoptosis A) is programmed cell death B) frees the fingers and toes of the human embryo from their 'webbed' structure to independent structures C) is a process that acts to decrease the number of somatic cells D) all of the choices are correct
D) all of the choices are correct
Binary fission in bacteria differs from mitosis because A) there is no nuclear membrane to break down and rebuild B) the chromosome is a simple DNA strand without complex proteins and no spindle forms C) the chromosome copies attach to the plasma membrane and are pulled part by cell growth D) all of the choices are correct E) none of the choices are correct
D) all of the choices are correct
Eukaryotic chromosomes A) may occur as chromatin B) consist of both DNA and protein C) contain histones responsible for packaging DNA to fit into a small space D) all of the choices are correct
D) all of the choices are correct
The function of mitosis is: A) to ensure that each new cell receives a complete set of genetic information B) asexual reproduction in some species C) growth of the organism and tissue repair D) all of the choices are correct
D) all of the choices are correct
Sources of genetic variation in a sexually reproducing population include(s) which of the following? A) fertilization B) crossing over in prophase I of meiosis C) independent assortment in metaphase I of meiosis D) all of the choices are sources of genetic variation E) none of the choices are sources of genetic variation
D) all of the choices are sources of genetic variation
Generally, animals build an organism using the diploid number of chromosomes. However, insects in the order of ants, wasps and bees can use a haploid-diploid system where adults of one sex are formed with a haploid number of chromosomes. This would mean that A) a female could determine the sex of the offspring by fertilizing or not fertilizing an egg B) a single set of chromosomes is sufficient to code for a functional individual C) the males and females are not equally "related" to their mothers considering the proportion of genes held in common D) all of the choices are true
D) all of the choices are true
What are alleles? A) recessive forms of a kind of characteristic carried by genes B) genes for different traits, such as hair color or eye color C) dominant forms of a kind of characteristic carried by genes D) alternative forms of a gene for a single trait, such as blue eyes or brown eyes E) the locations of genes on a chromosome
D) alternative forms of a gene for a single trait, such as blue eyes or brown eyes
Which of the following is NOT a difference between anaphase I and anaphase II? A) at the end of anaphase I, each chromosome of two chromatids and at the end of anaphase II, sister chromatids have separated, becoming daughter chromosomes B) sister chromatids separate during anaphase II while homologous chromosomes separate during anaphase I C) the cell undergoing anaphase II is genetically different from what it contained while undergoing anaphase I D) anaphase I occurs in a haploid cell while anaphase II occurs in a diploid cell
D) anaphase I occurs in a haploid cell while anaphase II occurs in a diploid cell
At which stage of meiosis is each chromosome composed of a single chromatid? A) prophase II B) metaphase II C) metaphase I D) anaphase II E) prophase I
D) anaphase II
Which of the following is NOT true concerning mitosis? A) mitosis allows growth and increase in size in both plants and animals B) both plant and animal cells undergo cytokinesis C) plant cells lack centrioles while animal cells do not D) animal cells form a cell plate during cytokinesis while plant cells do not
D) animal cells form a cell plate during cytokinesis while plant cells do not
What is the importance of crossing-over? A) it increases chromosome condensation B) it produces the proteins that are associated with DNA in chromosomes C) it separates the homologous chromosomes D) it increases the likelihood that daughter cells contain different genetic material E) it provides extra genetic material for the daughter cells
D) it increases the likelihood that daughter cells contain different genetic material
Species X reproduces asexually by fission and species Y reproduces sexually. Consider that all other relevant characteristics are similar between these species. When the environment changes, then A) species X should have a better chance of surviving than species Y B) neither species should have an advantage in surviving since organisms often become extinct when the environment changes C) species X and Y will have an equal chance of surviving D) species Y should have a better chance of surviving than species X
D) species Y should have a better chance of surviving than species X
It could be said that males are able to provide gametes with more genetic diversity than females for reproduction. One Maine reason would be A) crossing over occurs more often in the formation of sperm than in eggs B) sperm that contain a recombination of genes are usually more successful in fertilization an egg C) males provide more genes in sperm than females provide in eggs D) spermatogenesis in males results in four functional sperm while oogenesis in females results in only one egg and three structures that contain genetic information that is lost when they disintegrate
D) spermatogenesis in males results in four functional sperm while oogenesis in females results in only one egg and three structures that contain genetic information that is lost when they disintegrate
The ability to roll the edges of the tongue upward in a U-shape has been considered to be an inherited ability. The standard assumption is that tongue-rolling is a dominant allele at a single gene locus. Which of the following would cast doubt on this assumption? A) a teacher reports that after testing her class on the ability to roll their tongue, with very little effort the non-tongue-rollers can learn to also roll their tongues. B) a student who can roll his tongue has a mother and father, both of whom cannot C) a student who cannot roll his tongue has a mother and father, both of whom can D) two of the above are situations that would cast doubt on this assumption
D) two of the above are situations that would cast doubt on this assumption
Which of the following crosses would always result in offspring that only display the dominant phenotype? A) Tt x tt B) TT C) Tt x Tt D) two of the crosses will always display the dominant phenotype E) TT x TT
D) two of the crosses will always display the dominant phenotype
The diploid (2n) number of chromosomes for a human being is A) 24 B) 44 C) 48 D) 23 E) 46
E) 46
The offspring of a monohybrid test cross would have what possible genotypes(s)? A) AA, Aa, and aa B) aa only C) AA and Aa D) AA only E) Aa and aa
E) Aa and aa
In the use of a Punnett square for genetic results of crossing individuals A) the results show the offspring's expected genotypes B) all different kinds of sperm are lined up either horizontally or vertically C) all different kinds of eggs are lined up either horizontally or vertically D) only two of the choices are correct E) all of the choices are correct
E) all of the choices are correct
Which characteristic of pea plants were important in their selection as Mendel's research organism? A) many true-breeding varieties were available B) pea plants are self pollinating but can be cross-fertilized easily C) peas are easy to cultivate D) pea plants have a short generation time E) all of these were important characteristics in Mendel's selection
E) all of these were important characteristics in Mendel's selection
What occurs in anaphase? A) the nuclear envelope is constructed B) chromosomes line up along the equator of the dividing cell C) centrioles move to opposite poles D) the nuclear envelope disappears E) chromosomes move to opposite poles
E) chromosomes move to opposite poles
Which statement is NOT true about mitosis? A) mitosis is a process that duplicates and divides the nuclear contents only B) mitosis produces two daughter cells that contain the same kinds of chromosomes as the parent cell C) mitosis is involved in development of a fertilized egg into a multicellular organism D) mitosis produces two daughter cells that contain the same number of chromosomes as the parent cell E) mitosis uses a diploid (2n) parent cell to form daughter cells containing a haploid number (n) of chromosomes
E) mitosis uses a diploid (2n) parent cell to form daughter cells containing a haploid number (n) of chromosomes
Which does NOT occur in telophase? A) the nucleolus reforms B) chromosomes de-condense into chromatin C) cytokinesis is under way D) the nuclear envelope is being reconstructed E) the centromeres split
E) the centromeres split
Why do polar bodies form? A) the orient the egg for penetration by the sperm B) they nurse the egg as it leaves the follicle C) this is extra chromosomal material representing the X chromosome in each female cell D) they orient the sperm toward the egg E) they allow a reduction in chromosomes while preserving most of the cytoplasm for one egg
E) they allow a reduction in chromosomes while preserving most of the cytoplasm for one egg
