Biology online quiz 8

In a cell containing 10 chromosomes, meiosis results in the formation of daughter cells containing _____ chromosomes. 5 10 20 40 0

5 Haploid sex cells contain half as many chromosomes as diploid somatic cells.

The term binary fission is best applied to _____. nuclear chemistry plants prokaryotes mitosis chromosomes

Prokaryotes (such as bacteria) reproduce by a type of cell division called binary fission.

Which of the following is a key difference between meiosis and mitosis? Chromosomes align at the metaphase plate. Chromosomes condense. Chromosomes migrate to opposite poles. A spindle apparatus forms. Synapsis occurs.

Synapsis occurs. The pairing of homologous chromosomes during prophase I of meiosis is called synapsis.

Which of the following indicates Turner syndrome? XYY XO YO XY XXY

XO This is the sex chromosome complement of an individual with Turner syndrome.

The phase of mitosis during which the chromosomes move toward separate poles of the cell is _____. telophase anaphase metaphase prophase cytokinesis

anaphase Anaphase begins when the paired centromeres of each chromosome separate, liberating the sister chromatids, which begin moving toward opposite poles of the cell.

Which of the following is a feature of plant cell division that distinguishes it from animal cell division? lack of cytokinesis formation of a cell plate disappearance and subsequent reappearance of the nucleolus production of four (rather than two) new cells per mitotic division formation of a cleavage furrow

formation of a cell plate

Which of the following statements regarding the function of mitosis is false? Mitosis allows organisms to grow. Mitosis allows organisms to regenerate lost parts. Mitosis allows organisms to repair tissues. Mitosis allows organisms to reproduce asexually. Mitosis allows organisms to generate genetic diversity.

Mitosis allows organisms to generate genetic diversity.

During meiosis I, homologous chromosomes form a tetrad. What does this accomplish? A) This brings the chromosomes into alignment so that crossing over can create new combinations of genes present on a single chromosome. B) Crossing over can occur, creating new combinations of chromosomes through their independent alignment across the metaphase plate. C) It allows for the process of crossing over to occur, which reduces the number of chromosomes present in the cell. D) A chiasma forms as crossing over occurs, which ultimately reduces the number of chromatids per chromosome.

A) Crossing over does this by exchange of corresponding parts between homologous chromosomes, creating a patchwork of maternal and paternal chromosome segments along a single chromosome.

A fragment of chromosome 21 reattaches to chromosome 21, but in the reverse direction. What is the name given to this change? trisomy 21 deletion duplication translocation inversion

An inversion occurs when a fragment reattaches to the original chromosome but in the reverse direction. Usually, these aberrations result in fewer harmful effects than other chromosomal alterations as the genes are still present in their normal number.

What is the difference between a benign tumor and a malignant tumor? Benign tumors are a mass of essentially abnormal cells; malignant tumors are an abnormal mass of essentially normal cells. Benign tumors do not metastasize; malignant tumors do. Benign tumors metastasize; malignant tumors do not. Benign tumors will not kill you; malignant tumors will. Benign tumors spread beyond their original site; malignant tumors remain at their original site.

Benign tumors do not metastasize; malignant tumors do. Malignant tumors spread from their site of origin to other parts of the body.

Which of the following occurs during mitosis? Two genetically different daughter cells result. Organelles replicate. Chromatids separate. Chromosomes replicate. The cell divides into two separate cells.

Chromatids separate. This occurs during anaphase.

During meiosis, homologous chromosomes sometimes "stick together" and do not separate properly. This phenomenon is known as _____. cellular sterility meiotic failure gametic infertility nondisjunction sticky chiasmata

In nondisjunction, chromosomes fail to separate properly at meiosis.

During meiosis, the events that occur in _____ are similar to those that occur in _____ of mitosis. prophase I ... prophase metaphase I ... metaphase anaphase I ... anaphase II metaphase II ... metaphase telophase II ... telophase I

metaphase II ... metaphase Meiosis II is virtually identical to mitosis, which separates sister chromatids, but unlike meiosis I, which separates homologous chromosomes. However, each daughter cell produced by meiosis II has only a haploid, not diploid, set of chromosomes.