Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Chapter 10 – Chromosomes, Mitosis and Meiosis This chapter begins an examination of one of the major the major themes of biology – the transmission of information, specifically, the transmission of information from one generation of cell or organism to the next. In prokaryotes, the information is contained in a single circle of DNA. In eukaryotes, it is carried in the chromosomes contained within the cell nucleus. Chromosomes are made up of DNA and protein. The DNA is organized into informational units, or genes, that determine the characteristics of the organism. Each species in unique due to the information specified by its genes. Genes are passed from parent cell to daughter cell by a process that ensures that each new nucleus receives the same number and types of chromosomes as were present in the original nucleus. There are two basic types of reproduction – asexual and sexual. In asexual reproduction, a single parent cell usually splits, buds, or fragments into two or more individuals. In sexual reproduction, sex cells, or gametes, are produced by a process that halves the number of chromosomes in the resulting cells. When two gametes fuse, the resulting cell contains the same number of chromosomes as the parent cells. INTRODUCTION 1. Cells contain a massive amount of precisely coded genetic information in the form of DNA, collectively called the organism’s _____________ EUKARYOTIC CHROMOSOMES 2. DNA and associated proteins form a complex, the ______________________ , that make up chromosomes. DNA is organized into information units called genes. 3. According to the Human Genome Project, humans have about ____________ genes that code for proteins. DNA is packaged in a highly organized way in chromosomes. 4. Positively charges histones associate with DNA forming structures called __________________ Chromosome number and informational content differ among species 5. Most human body cells have exactly ______________ (#?) chromosomes. THE CELL CYCLE AND MITOSIS 6. The period from the beginning of one cell division to the beginning of the next cell division is the _________________________________ Chromosomes duplicate during interphase 7. Interphase is divided into the G1 phase, which stands for (a) ____________________ phase, the S phase, or (b) ___________________ phase, and the G2 phase, or (c) __________________ phase During prophase, duplicated chromosomes become visible within the microscope 8. Each chromatid includes a constricted region called the _________________ 9. Attached to each centromere is a _______________ ,a structure formed from proteins to which microtubules can bind. 10. Some of the microtubules radiating from each pole elongate toward the chromosome, forming the ___________________, which separates the chromosomes during anaphase. Prometaphase begins when the nuclear envelope breaks down 11. In prometaphase, sister chromatids of each duplicated chromosome become attached to _______________ at opposite poles of the cell. Duplicated chromosomes line up on the midplane during metaphase 12. During, all of the cell’s chromosomes align at the cell’s midplane , or ___________ During anaphase, chromosomes move toward the poles 13. Kinetochore microtubules shorten, or ________________ , during anaphase During telophase, two separate nuclei form 14. Telophase is characterized by the ___________________________________ and a return to interphase-like condition Cytokinesis forms two separate daughter cells 15. In plant cells, cytokinesis occurs by forming a ____________________ , a partition constructed in the equatorial region of the spindle and growing laterally toward the cell wall Mitosis produces two cells genetically identical to the parent cell 16. The regularity of the process of cell division ensures that each daughter nucleus receives exactly the same number and kinds of ______________________ the parent cell had Lacking nuclei, prokaryotes divide by binary fission 17. The reproduction process in which one cell divides into two offspring cells is named __________________ REGULATION OF THE CELL CYCLE 18. __________________________ are a group of plant hormones that promote mitosis both in normal growth and in wound healing SEXUAL REPRODUCTION AND MEIOSIS 19. Offspring inherit traits that are virtually identical to those of their single parent when reproduction is ___________________________ 20. In (a) ____________________ reproduction, offspring receive genetic information from two parents. Haploid (n) gametes from the parents fuse to form a single (b) ____________ (2n) cell called the (c) _______________ 21. Homologous chromosomes are members of a pair of chromosomes that are similar in ________________________________ Meiosis produces haploid cells with unique gene combinations 22. Meiosis typically consists of two nuclear and cytoplasmic divisions referred to as ___________________ Prophase I includes synapsis and crossing-over 23. During prophase I, homologous chromosomes come to lie lengthwise side by side in a process known as _________________ 24. Homologous chromosomes exchange genetic material (crossing over) during the first meiotic (a) ____________________, providing more (b) ___________________ among gametes and offspring During meiosis I, homologous chromosomes separate 25. The haploid condition is established as the members of each pair of homologous chromosomes separate during the first meiotic __________________ Chromatids separate in meiosis II 26. In metaphase II, chromatids are arranged in bundles of (a) __________________, and in metaphase II, chromatids are in groups of (b) __________________ Mitosis and meiosis lead to contrasting outcomes 27. (a) ____________________________ results in two daughter cells identical to the original cell. (b) ____________ results in four genetically different, haploid daughter cells. The timing of meiosis in the life cycle varies among species 28. Sex cells (sperm and egg or ova) are known as (a) ___________________, therefore, the formation of sex cells is referred to (b) _____________________ 29. The formation of sperm is called _______________ 30. The formation of egg or ova is called ________________ Building Words – use combinations of prefixes and suffixes to build words for the definitions that follow Prefixes The meaning Suffixes The meaning Centrocenter -gen(esis) production of Chromocolor -mere part Dipldouble, in pairs -phyte plant Gametosex cells, eggs and sperm -some body Haplsingle Interbetween ooegg spermatoseed, “sperm” sporospore Prefix ___________ Suffix ____________ ___________ -phase ___________ ___________ ___________ -oid -oid ____________ ___________ ___________ ___________ ___________ ____________ ____________ ____________ ____________ ___________ ____________ Definition 1. A dark staining body within the cell nucleus containing genetic information 2. The stage in the life cycle of a cell that occurs between successive cell divisions 3. An adjective pertaining to a single set of chromosomes 4. An adjective pertaining to a double set of chromosomes 5. The constricted part or region of a chromosomes (often near the center) to which a spindle fiber is attached 6. The process by which gametes (sex cells) are produced 7. The process whereby sperm are produced 8. The process whereby eggs are produced 9. The stage in the life cycle of a plant that produces gametes by mitosis 10.The stage in the life cycle of a plant that produces spores by meiosis Matching a. anaphase e. interkinesis i. mitosis m. synapsis b. chromatin f. kinetochore j. polyploidy n. telophase c. crossing over g. meiosis k. prophase d. cytokinesis h. metaphase l. S phase For each of these definitions, select the correct matching term from the list above ____ 1. The last stage of mitosis and meiosis ____ 2. The phase in interphase during which DNA and other chromosomal components are synthesized ____ 3. Portion of the chromosome centromere to which the mitotic spindle fibers attach ____ 4. Process whereby genetic material is exchanged between homologous chromatids during meiosis ____ 5. The phase in mitosis during which the chromosomes line up along the equatorial plate ____ 6. DNA-protein fibers that condense to form chromosomes during prophase ____ 7. Process during which a diploid cell undergoes two successive nuclear divisions resulting in four haploid cells ____ 8. Have more than two sets of chromosomes per nucleus ____ 9. Division of the cell nucleus resulting in two daughter cells with the identical number of chromosomes as the parental cell ____10.Stage of cell division in which the cytoplasm divides into two daughter cells Making Comparisons – fill in the blanks Event Chromosome compaction (condensation) Cytokinesis Homologous chromosomes move to opposite poles Tetrads form Cytokinesis occurs Chromatids separate Chromosomes line up at the midplane of the cell Duplication of DNA Mitosis Prophase Meiosis Prophase I, prophase II #1 #3 #2 #4 #5 #7 #9 #11 #6 #8 #10 #12 #13 #14