PDF-1. If an organism has 15 pairs of homologous chromosomes, how many ch

2n 2n Meiosis 2 How many DNA molecules are present in a chromosome of a cell in metaphase of mitosis How many DNA molecules are present in a chromosome of a cell at metaphase II. Featured . plant genetics topic . of local and timely interest: . The 2014 GMO . Ballot Measure. Focusing . on a plant: Roundup Ready sugar beets . in the Willamette Valley. http://www.nwfoodnews.com/2011/02/18/meet-the-sugar-beet/. http://www.youtube.com/watch?v=lJzZ7p-47P8&feature=related. . State that meiosis is a reduction division of a diploid nucleus to form a haploid . nulcei. .. Define homologous chromosomes. Outline the process of meiosis, including pairing of homologous chromosomes and crossing over, followed by two divisions, which . Homologous chromosomes . – identical chromosomes. . …same length, . centromere. , same staining pattern. . …exception…males sex chromosome. 1-22 . autosomes. . sex . chromsomes. Homologous chromosomes. CfE Advanced Higher Biology. Unit 2: Organisms and Evolution. 2bii. – Meiosis forms variable gametes. Terminology (4). Sexual life cycle of animals (1). Meiosis – an overview (1). Meiosis I (4). Alleles segregate during meiosis allowing new combinations to be formed by the fusion of gametes. . Understandings:. One diploid nucleus divides by meiosis to produce four haploid nuclei. . The halving of the chromosome number allows a sexual life cycle with fusion of gametes. . diploid. Sex cells (gametes/germ cells) have only one set of chromosomes . . = . haploid. . That means when fertilization . occurs, the new individual will. have the correct number of chromosomes.. Key Concepts:. What happens during the process of meiosis?. How is meiosis different from mitosis?. Types of . Reproduction. Section 11-4. ASEXUAL. SEXUAL. 1. One Parent. 2. Binary fission (in prokaryotes) or mitosis in (eukaryotes).. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings. Cell Cycle. 3. A . life cycle. of an organism is the generation-to-generation sequence of stages in its reproductive history.. Crossing over . The term crossing over was coined by Morgan.. In crossing over , exchange the chromosomal parts or segments in the non-sister chromatids of homologous chromosomes. . In another words , . Why do cells need to divide?. As . cells grow larger, they start to face several . difficulties . in functioning:. Growth & Repair. In order for multi-cellular organisms to grow, cells must divide. If cells are lost due to injury or damage to DNA, . 22 pairs of autosomes. 1 pair of sex chromosomes. XX = Female, XY = Male. Karyotype - chromosomes are arranged according to shape and size. AN EXTRA COPY OF CHROMOSOME 21 CAUSES DOWN SYNDROME. This condition is called . They are also called as mega chromosomes. . These chromosomes are very long and thick in appearance during metaphase than normal chromosomes.. Hence they are called as Giant chromosomes.. The Giant chromosomes are of two types-. Get a flash card and quiz at least three people then have a seat to start your quick write.. Quick write. Continuity and Change. —All species tend to maintain themselves from generation to generation using the same genetic code. However, there are genetic mechanisms that lead to change over time, or evolution.. 1. 2. Sexual Reproduction. . Involves the production of sex cells (gametes) and the fusion of their nuclei (fertilization), producing a fertilized egg cell (zygote). Gametes. Fertilization. 3.