Bio 1107 Final Exam Study Guide

Bio 1107 Final Exam Study Guide 1) The centromere is a region in which - ✔✔A) chromatids remain attached to one another until anaphase. 2) Starting with a fertilized egg (zygote), a series of five cell divisions would ...

Bio 1107 Final Exam Study Guide 1) The centromere is a region in which - ✔✔A) chromatids remain attached to one another until anaphase. 2) Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells? - ✔✔D) 32 3) If there are 20 chromatids in a cell, how many centromeres are there? - ✔✔A) 10 4. At which phase are centrioles beginning to move apart in animal cells? - ✔✔E) prophase 5. Where do the microtubules of the spindle originate during mitosis in both plant and animal cells? - ✔✔B) centrosome 6. Movement of the chromosomes during anaphase would be most affected by a drug that - ✔✔D) prevents shortening of microtubules. 7. A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 8 picograms of DNA per nucleus. How many picograms would be found at the end of S and the end of G₂? - ✔✔D) 16; 16 8. For anaphase to begin, which of the following must occur? - ✔✔C) Cohesin must be cleaved enzymatically. 9. Which of the following best describes how chromosomes move toward the poles of the spindle during mitosis? - ✔✔D) The chromosomes are "reeled in" by the contraction of spindle microtubules, and motor proteins of the kinetochores move the chromosomes along the spindle microtubules. 10. What is a cleavage furrow? - ✔✔C) a groove in the plasma membrane between daughter nuclei 11. Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in concentration during the cell cycle, are called - ✔✔E) cyclins. 12. Cells from an advanced malignant tumor most often have very abnormal chromosomes, and often an abnormal total number of chromosomes. Why might this occur? - ✔✔C) Chromosomally abnormal cells can still go through cell cycle checkpoints. 13. Besides the ability of some cancer cells to overproliferate, what else could logically result in a tumor? - ✔✔C) lack of appropriate cell death 14. After which checkpoint is the cell first committed to continue the cell cycle through M? - ✔✔B) G₁ 22. The human genome is minimally contained in which of the following? - ✔✔A) every human cell 23. Which of the following is a true statement about sexual vs. asexual reproduction? - ✔✔B) In sexual reproduction, individuals transmit 50% of their genes to each of their offspring. 24. Which of the following defines a genome? - ✔✔E) the complete set of an organism's genes Eukaryotic sexual life cycles show tremendous variation. Of the following elements, which do all sexual life cycles have in common? I. Alternation of generations II. Meiosis III. Fertilization IV. Gametes V. Spores - ✔✔C) II, III, and IV 26. Which of these statements is false? A) In humans, each of the 22 maternal autosomes has a homologous paternal chromosome. B) In humans, the 23rd pair, the sex chromosomes, determines whether the person is female (XX) or male (XY). C) Single, haploid (n) sets of chromosomes in ovum and sperm unite during fertilization, forming a diploid (2n), single-celled zygote. D) At sexual maturity, ovaries and testes produce diploid gametes by meiosis. E) Sexual life cycles differ with respect to the relative timing of meiosis and fertilization. - ✔✔D) At sexual maturity, ovaries and testes produce diploid gametes by meiosis. 27. The karyotype of one species of primate has 48 chromosomes. In a particular female, cell division goes awry and she produces one of her eggs with an extra chromosome (25). The most probable source of this error would be a mistake in which of the following? - ✔✔E) either anaphase I or II 28. A given organism has 46 chromosomes in its karyotype. We can therefore conclude which of the following? - ✔✔E) Its gametes must have 23 chromosomes. 29. A triploid cell contains three sets of ch