Exam 11: Sexual Reproduction and Meiosis

A cell biologist examines a skin cell from a lizard during metaphase of mitosis and determines that 20 chromatids are present.The role of meiosis in this species is to (Check all that apply)

All animal cells are diploid except

Which best describes the process of independent assortment?

During anaphase I,which best represents segregation of the chromatids that make up one pair of homologues? (M represents a maternal chromatid and P represents a paternal chromatid.Assume no crossing over occurs.)

In animals,the cells that will eventually undergo meiosis to produce gametes are set aside early in development.These are called

Which statement about the reductive division of meiosis is false?

You are comparing the events of meiosis I in cells from several different organisms.You come across one species in which you do not observe any chiasmata.The best conclusion to make is

The Rec8 protein holds sister chromatids together during meiosis.If an individual has a mutation that prevents degradation of Rec8,this would most likely prevent

All of the following increase genetic variation EXCEPT

The most common form of gene therapy involves inserting a normal gene into cells that contain a defective version of the gene.In order to use gene therapy to prevent a man from passing a defective gene on to future generations,you should try to insert normal copies of the gene into

You are studying meiosis in an organism where 2n = 28.How many chromosomes will be present in each cell after meiosis I is complete but before meiosis II begins?

Which structures indicate where crossing over has occurred?

Non-disjunction is the failure of homologous chromosomes to separate during meiosis I,or the failure of sister chromatids to separate during meiosis II or mitosis.As a result,both homologous chromosomes or both sister chromatids migrate to the same pole of the cell.This produces daughter cells with an imbalance of chromosomes.If 18 pairs of sister chromatids segregate normally during meiosis II in cats (n=19)but we have non-disjunction of 1 pair,then at the end of meiosis II we will have

The cell produced by the fusion of an egg and a sperm is the

In plants and animals,the zygote develops by which of the following processes?

Which of the following produces new cells that are genetically identical to the original cell?

In 95% of cases of Down's syndrome,there is one extra chromosome (number 21)in every cell.This aneuploid condition is most likely the result of

Which of the following is likely to occur if you were to prevent cyclin B from associating with its cyclin-dependent kinase near the end of meiosis I?

A cell biologist examines a leaf cell from an alfalfa plant during metaphase of mitosis and determines that 32 chromatids are present.The role of fertilization in this species is to (Check all that apply)

________ cells contain one set of chromosomes.