Chapter 12 Mastering biology

prophase

At which phase of the cell cycle do centrioles begin to move apart in animal cells? telophase anaphase prophase metaphase

64

Part complete Starting with a fertilized egg (zygote), a series of six cell divisions would produce an early embryo with how many cells? 32 64 12 16

a plant cell in the process of cytokinesis

Part complete Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely ________. an animal cell in the process of cytokinesis a plant cell in the process of cytokinesis an animal cell in anaphase of mitosis a plant cell in metaphase of mitosis

DNA and proteins

Eukaryotic chromosomes are composed of which of the following macromolecules? DNA and phospholipids DNA and proteins DNA only DNA and RNA

large cells containing many nuclei

In some organisms, such as certain fungi and algae, cells undergo the cell cycle repeatedly without subsequently undergoing cytokinesis. What would result from this? See Concept 12.2 (Page 241) View Available Hint(s) a rapid rate of gamete production inability to duplicate DNA division of the organism into many cells, most lacking nuclei large cells containing many nuclei a decrease in chromosome number

separation of sister chromatids

The mitotic spindle plays a critical role in which of the following processes? triggering the compaction and condensation of chromosomes splitting of the cell (cytokinesis) following mitosis dissolving the nuclear membrane separation of sister chromatids

Each chromosome is made of a complex of DNA and associated proteins.

If a eukaryotic cell is in the G1 phase of the cell cycle, which statement about the cell's chromosomes must be correct? -Each chromosome consists of two identical chromatids. -Each chromosome is made of a complex of DNA and associated proteins. -The chromosomes are preparing for DNA synthesis.

alignment of chromosomes on the equator of the cell

Metaphase is characterized by ________. cytokinesis separation of the centromeres alignment of chromosomes on the equator of the cell separation of sister chromatids

92 Mitosis follows the duplication of the cell's DNA

Part complete A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain? See Concept 12.1 (Page 236) View Available Hint(s) -46 -23 or 46, depending on the portion of prophase examined -46 or 92, depending on the portion of prophase examined -92 -23

anaphase

Part complete During which phase of mitosis do the chromatids become chromosomes? prophase metaphase anaphase telophase

normal growth and cell function

Part complete G1 is associated with which of the following cellular events? normal growth and cell function DNA replication break down of the nuclear membrane the beginning of mitosis

10

Part complete If a cell at metaphase of mitosis contains 20 sister chromatids, how many chromosomes will be present in a G1 cell? 10 5 20 40

attachment of microtubules to kinetochores

Part complete In the cells of many eukaryotic species, the nuclear envelope has to disappear to permit which of the following events in the cell cycle? attachment of microtubules to kinetochores separation of the centrosomes condensation of the chromosomes DNA synthesis

cells with more than one nucleus.

Part complete In the cells of some organisms, mitosis occurs without cytokinesis. This will result in cells that are unusually small. cells lacking nuclei. destruction of chromosomes. cell cycles lacking an S phase. cells with more than one nucleus.

G1: follows cell division

Which of the following correctly matches a phase of the cell cycle with its description? See Concept 12.2 (Page 237) View Available Hint(s) G2: cell division G1: follows cell division S: immediately precedes cell division M: duplication of DNA All of the above are correctly matched.

replication of the DNA

Which of the following does not occur during mitosis? replication of the DNA spindle formation separation of the spindle poles condensation of the chromosomes separation of sister chromatids