BioChp8

Asexual and sexual reproduction differ in that sexual reproduction _____.

Consider the process by which bacterial populations grow. What process performs a similar function in humans?

During binary fission, the replicated bacterial chromosome attaches to the plasma membrane by specialized anchor proteins. What is the purpose of this attachment between chromosome and membrane?

Within one chromosome, what is the relationship between the sequence of bases in DNA of one sister chromatid compared to the other?

Which of the following statements correctly describes the timing of DNA synthesis?

What would be the immediate consequence of destroying a cell's centrosomes?

During mitosis, the chromosomes move because _____.

A cell is treated with a drug that prevents the formation of intracellular (within the cell) vesicles. Which of the following processes would be blocked?

In the laboratory, cancer cells fail to show density-dependent inhibition of growth in cell culture. What is one explanation that could account for this?

When examining cells in the laboratory, you notice that a particular cell has half as much DNA as the surrounding cells. It appears that this cell's cell cycle halted at checkpoint _____.

A benign and a malignant tumor differ in that _____.

When forming buds, hydras _____.

In many organisms, including humans, chromosomes are found in homologous pairs. Homologous chromosomes _____.

Baker's yeast is an organism with 32 chromosomes that can perform asexual or sexual reproduction and exist as both a diploid and haploid cell. After meiosis, how many chromosomes will be present in each cell?

The M phase of mitosis and M phase of meiosis both occur after interphase. However, the two processes differ in the arrangement and behavior of their chromosomes. How?

At the conclusion of meiosis I, the daughter cells are _____.

In meiosis II, _____.

If we assume that crossing over does not occur, how many different combinations of chromosomes are possible in a zygote derived from diploid parents who have 3 pairs of of chromosomes?

Inbreeding has a number of interesting effects. For one, highly inbred strains (varieties) may carry identical forms of every gene. Mice have 40 chromosomes in their diploid (2n) set. How many genetically distinct kinds of gametes (gametes with different genetic characteristics) could be produced through meiosis in an inbred strain where there are identical forms of every gene?

During meiosis I, homologous chromosomes form a tetrad. What does this accomplish?

In a cell with eight chromosomes, one chiasma develops during meiosis I in only one particular pair of homologs. How many recombinant chromosomes will there be at the completion of meiosis II?

Scientists commonly choose white blood cells that are going through mitosis to prepare karyotypes. Why?

Although in humans there are 22 pairs of autosomal chromosomes, only three different chromosomal trisomies are commonly seen in newborns. Of the remaining 19 autosomes, many trisomies have not been seen in newborns. Why not?

In theory, when a nondisjunction for chromosome 18 occurs during meiosis I, four gametes can be produced. If these gametes are fertilized with unaffected gametes from the second parent, what observations would you make concerning the resulting embryos?

Trisomy for most autosomes is fatal, yet trisomy or even tetrasomy (four copies) of the X chromosome is not. What is the explanation for this difference?

You suspect that a serious developmental disorder is due to a chromosome abnormality and prepare a karyotype from an affected individual. In analyzing the karyotype, how could you distinguish trisomy from a chromosome structural defect such as a duplication?