MULTIPLE CHOICE: Select the BEST ANSWER for each item by ENCIRCLING THE LETTER corresponding to the best choice. Which of the following statements is INCORRECT?The halving of chromosome number during gamete formation, followed by the union of two gametes at fertilization, allows a constant 2n number of chromosomes to be maintained from generation to generation in all individuals of a species.Meiosis ensures that all somatic cells of the developing individual have identical diploid chromosome sets.The number of chromosomes in a normal diploid cell is 2n.Gametes and other cells that carry only a single set of chromosomes are called haploid. Which of the following statements is INCORRECT?Scientists usually analyze the chromosomal makeup of a cell during metaphase because this is when the chromosomes are most visible.During metaphase, individual chromosomes have duplicated and condensed from thin threads into compact rod-like structures.Each chromosome, during metaphase, consists of two identical halves known as sister chromatids.The location at which sister chromatids are attached to each other is called the kinetochore. Which of the following statements is INCORRECT?Homologous chromosomes match in size, shape, and banding.Homologous chromosomes may carry different alleles, but always carry the same set of genes.Chromosomes 1 and 2 are homologous chromosomes.In males, X and Y chromosomes are nonhomologous chromosomes. Which of the following statements is INCORRECT?A karyotype is an array of chromosomes in a given cell.In a normal human male karyotype, the 44 chromosomes in matching pairs are called autosomes.In a normal human female karyotype, there are 23 homologous pairs of chromosomes.The number of chromosomes correlates with size or complexity of the organism. Which of the following statements is INCORRECT?In humans, the X chromosome is larger than the Y chromosome.The presence or absence of the Y chromosome in humans determines sex.Pseudoautosomal regions are found on both ends of the X and Y chromosomes.Loss of function of the SRY gene leads to testicular development. Which is NOT TRUE of sex-reversed females?One X chromosome and one Y chromosome are present.Two X chromosomes are present, but one of the two carries a portion of the Y chromosome.Sex-reversed females always have a Y chromosome lacking a functional SRYThe SRY gene may have been replaced by a portion of the X chromosome. Which region(s) in X and Y chromosomes is/are considered homologs?A.Male-specific regionC.Sex-determining region of YB.Pseudoautosomal regions 1 and 2D.Male fertility genes Which is NOT TRUE of the S phase?DNA undergoes semiconservative replication.Identical sister chromatids are formed from duplication of each chromosome.Sister chromatids of each chromosome remain joined to each other at their centromeres.A human cell after the S phase has now 4n = 92 chromosomes. Which is NOT TRUE of G2?It usually lasts about 3 hours.It is the interval between chromosome duplication and beginning of mitosis.It is during this stage the cell achieves most of its growth.A human cell during G2 has 92 chromatids. The following are cellular events during prophase, EXCEPT:There is gradual condensation of chromosomes from the undifferentiated mass of chromatin.Darkly staining nucleoli begin to break down and disappear.Centrosomes move apart toward opposite poles and generate new microtubules.The nuclear membrane is broken down. The following are cellular events during prometaphase, EXCEPT:The breaking down of the nuclear membrane allows microtubules to invade the nucleus.Sister chromatids attach to microtubules from opposite centrosomes through centromeres.Polar microtubules are directed toward the middle of the cell.Astral microtubules extend out from the centrosome toward the cell’s periphery. Which is NOT TRUE of metaphase?Chromosomes align on the metaphase plate.The sister chromatids are facing opposite poles.Sister chromatids are pulled in opposite directions while they are still connected to each other by the tight cohesion of their centromeres.A human cell during G2 has 4n = 92 chromosomes. Which is NOT TRUE of anaphase?The centromeric connections between sister chromatids are severed.All chromosomes have a characteristic V shape during anaphase.As the chromosome moves toward the pole, its kinetochore microtubules shorten.A human nucleus during anaphase has 4n = 92 chromosomes. Which is NOT TRUE of telophase?A nuclear envelope forms around the group of chromosomes at each pole.Chromosomes uncoil and become a tangle of chromatin.The spindle fiber begins to disperse.Two separate daughter cells are formed. __________ refer to points of the cell cycle where the cell evaluates the results of previous steps:A.CytokinesisC.Regulatory signalsB.Intrinsic factorsD.Regulatory checkpoints

Question

MULTIPLE CHOICE: Select the BEST ANSWER for each item by ENCIRCLING THE LETTER corresponding to the best choice. Which of the following statements is INCORRECT?The halving of chromosome number during gamete formation, followed by the union of two gametes at fertilization, allows a constant 2n number of chromosomes to be maintained from generation to generation in all individuals of a species.Meiosis ensures that all somatic cells of the developing individual have identical diploid chromosome sets.The number of chromosomes in a normal diploid cell is 2n.Gametes and other cells that carry only a single set of chromosomes are called haploid. Which of the following statements is INCORRECT?Scientists usually analyze the chromosomal makeup of a cell during metaphase because this is when the chromosomes are most visible.During metaphase, individual chromosomes have duplicated and condensed from thin threads into compact rod-like structures.Each chromosome, during metaphase, consists of two identical halves known as sister chromatids.The location at which sister chromatids are attached to each other is called the kinetochore. Which of the following statements is INCORRECT?Homologous chromosomes match in size, shape, and banding.Homologous chromosomes may carry different alleles, but always carry the same set of genes.Chromosomes 1 and 2 are homologous chromosomes.In males, X and Y chromosomes are nonhomologous chromosomes. Which of the following statements is INCORRECT?A karyotype is an array of chromosomes in a given cell.In a normal human male karyotype, the 44 chromosomes in matching pairs are called autosomes.In a normal human female karyotype, there are 23 homologous pairs of chromosomes.The number of chromosomes correlates with size or complexity of the organism. Which of the following statements is INCORRECT?In humans, the X chromosome is larger than the Y chromosome.The presence or absence of the Y chromosome in humans determines sex.Pseudoautosomal regions are found on both ends of the X and Y chromosomes.Loss of function of the SRY gene leads to testicular development. Which is NOT TRUE of sex-reversed females?One X chromosome and one Y chromosome are present.Two X chromosomes are present, but one of the two carries a portion of the Y chromosome.Sex-reversed females always have a Y chromosome lacking a functional SRYThe SRY gene may have been replaced by a portion of the X chromosome. Which region(s) in X and Y chromosomes is/are considered homologs?A.Male-specific regionC.Sex-determining region of YB.Pseudoautosomal regions 1 and 2D.Male fertility genes Which is NOT TRUE of the S phase?DNA undergoes semiconservative replication.Identical sister chromatids are formed from duplication of each chromosome.Sister chromatids of each chromosome remain joined to each other at their centromeres.A human cell after the S phase has now 4n = 92 chromosomes. Which is NOT TRUE of G2?It usually lasts about 3 hours.It is the interval between chromosome duplication and beginning of mitosis.It is during this stage the cell achieves most of its growth.A human cell during G2 has 92 chromatids. The following are cellular events during prophase, EXCEPT:There is gradual condensation of chromosomes from the undifferentiated mass of chromatin.Darkly staining nucleoli begin to break down and disappear.Centrosomes move apart toward opposite poles and generate new microtubules.The nuclear membrane is broken down.  The following are cellular events during prometaphase, EXCEPT:The breaking down of the nuclear membrane allows microtubules to invade the nucleus.Sister chromatids attach to microtubules from opposite centrosomes through centromeres.Polar microtubules are directed toward the middle of the cell.Astral microtubules extend out from the centrosome toward the cell’s periphery. Which is NOT TRUE of metaphase?Chromosomes align on the metaphase plate.The sister chromatids are facing opposite poles.Sister chromatids are pulled in opposite directions while they are still connected to each other by the tight cohesion of their centromeres.A human cell during G2 has 4n = 92 chromosomes. Which is NOT TRUE of anaphase?The centromeric connections between sister chromatids are severed.All chromosomes have a characteristic V shape during anaphase.As the chromosome moves toward the pole, its kinetochore microtubules shorten.A human nucleus during anaphase has 4n = 92 chromosomes. Which is NOT TRUE of telophase?A nuclear envelope forms around the group of chromosomes at each pole.Chromosomes uncoil and become a tangle of chromatin.The spindle fiber begins to disperse.Two separate daughter cells are formed. __________ refer to points of the cell cycle where the cell evaluates the results of previous steps:A.CytokinesisC.Regulatory signalsB.Intrinsic factorsD.Regulatory checkpoints

Accepted Answer

1. Meiosis ensures that all somatic cells of the developing individual have identical diploid…

A.	Male-specific region	C.	Sex-determining region of Y
B.	Pseudoautosomal regions 1 and 2	D.	Male fertility genes

A.	Cytokinesis	C.	Regulatory signals
B.	Intrinsic factors	D.	Regulatory checkpoints