Chromosome I is metacentric, chromosome II is telocentric, chromosome III is submetacentric, and chromosome IV is acrocentric.  Draw a detailed picture of a germ cell from this organism in Metaphase of Mitosis and label all chromosomal and cellular components. Be sure to label each chromosome (I, II, III, or IV) and include the following in your drawing: centrosomes, 3 kinds of microtubules, metaphase/equatorial plate, and plasma membrane. Use the letter p to indicate a paternal chromosome and m to indicate a maternal chromosome.

The diploid number of chromosomes in the mustard plant, Arabidopsis thaliana, is 10. Knowing this, answer the following questions about the stages of mitosis.How many chromosomes will be found in each cell during prophase?

In which stage(s) of the cell cycle, mitosis or meiosis  do each of these processes occur (multiple stages apply to some) Crossing-over:  Chromosome supercoiling:  Separation of sister chromatids:  DNA synthesis:  Chromosome reduction from 2N to N:    4. A previously undiscovered single celled organism was found living at a great depth on the ocean floor. Its nucleus contains only a single, linear chromosome consisting of  7x10^6 nucleotide pairs of DNA coalesced with three types of histone-like proteins. The analysis of individual nucleosomes revealed that each unit contained one copy of each protein and that the short linker DNA had no protein bound to it If the entire chromosome consists of nucleosomes (discounting any linker DNA), how many are there and how many total proteins are needed to form them?

The following diagram is meant to help you understand how the amount of DNA in a cell changes as the cell cycle progresses. On the diagram, identify two of the stages of the cell cycle being described and identify how much DNA exists per cell, where a cell is defined as a distinct nucleus. Note that the sequence of images highlights one of the chromosomes of the cell. The other chromosomes, while also present, are faded in the background. Stage in Cell Cycle: A Status of Chromosomes: (Only one of the chromosomes is intensely colored) NANA INNNNNNN wwwww wwwNYA wwwww WXXXX VANNNNNN www Amount of DNA Per Cell: C NNNNA NNNNNN WWXXXXX NNNNNNE WNNNN www B NNNNN Between 1X and 2X 2X D 1X

3 6 points A diploid cell in G1 of interphase has eight chromosomes. How many chromosomes and DNA molecules will be found per cell when this original cell progresses to the following stages? Complete the table below. Anaphase II G1 of interphase G2 of interphase- Telophase 1 (after cytokinesis) Anaphase I S 8 chromosomes/cell and 8 DNA molecules/cell 8 chromosomes/cell and 16 DNA molecules/cell 8 chromosomes/cell and 8 DNA molecules/cell 8 chromosomes/cell and 16 DNA molecules/cell 8 chromosomes/cell and 16 DNA molecules/cell Prophase II Telophase II (after cytokinesis) Metaphase I Metaphase II 8 chromosomes/cell and 16 DNA molecules/cell 4 chromosomes/cell and 8 DNA molecules/cell

Why do eukaryotic cells need to go through the elaborate procedure of mitosis rather than simply dividing during interphase? Select as many answers as apply. 1.Daughter cells must be genetically identical to the mother cell, for homeostasis and ordered tissue growth.  2.Bivalent chromosomes must condense and be separated in an orderly fashion, to allow equal distribution of copies into daughter cells 3.Physically dividing the nucleus during interphase would likely lead to gross chromosome breakage and highly unequal assortment of genetic information into daughter cells. 4.Dividing the nucleus during interphase would have the same outcome as mitosis 5.Daughter cells must have half the number of chromosomes after mitosis than the mother cells 6.The homologous pairs of chromosomes need to be separated, to ensure copies go to the daughter cells.

The same chromosome can look very different depending on when in meiosis it is observed.  Explain fully why this is so and also why the chromosome is less condensed during some parts of the cell cycle?  How many DNA molecules does each chromosome contain at the beginning of Prophase I?  Use the following terms in your explanation: chromatin, histone, chromatid, centromere.