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c. ER - Deepwater.org
c. ER - Deepwater.org

... 29. The English physician Ronald Ross wanted to try to find the cause of malaria. Based on his observations, Dr. Ross suggested that the Anopheles mosquito might spread malaria from person to person. This suggestion was a a. prediction. c. theory. b. hypothesis. d. scientific “truth.” 30. Dr. Ross k ...
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... • Mendel concluded that the two “units” for the first trait were to be assorted into gametes independently of the two “units” for the other trait • Members of each pair of homologous chromosomes are sorted into gametes at random during meiosis ...
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printer-friendly version of benchmark

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... • This is because both sexes have at least one X chromosome in their genome. • XX (Female and homologous) ; XY (Male and heterologous) – Sex chromosomes undergo very little crossover during Prophase I of Meiosis. ...
Cengage Learning
Cengage Learning

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... diploid part of the life cycle, and it was immediately followed by meiosis. Thus, the zygote directly gave rise to spores and the haploid generation was re-established. The gap from four derivatives to more than four has already been bridged in some algal species by an intercalated mitotic division. ...
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the Note

... (Note that the F1 offspring show characteristics from both parents.) The plants of the F1 grow and mature. When they are ready to reproduce, they produce gametes for tallness (T) and shortness (t) because the gametes segregate (T + T + t + t) during meiosis. One half of the gametes will contain the ...
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... b. Label the phases of mitosis in the pictures below. (interphase, prophase, metaphase, anaphase, telophase, and cytokinesis). Also label the arrows. ...
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Meiosis



Meiosis /maɪˈoʊsɨs/ is a specialized type of cell division which reduces the chromosome number by half. This process occurs in all sexually reproducing single-celled and multi-celled eukaryotes, including animals, plants, and fungi. Errors in meiosis resulting in aneuploidy are the leading known cause of miscarriage and the most frequent genetic cause of developmental disabilities. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells each with half the number of chromosomes as the original parent cell. The two meiotic divisions are known as meiosis I and meiosis II. Before meiosis begins, during S phase of the cell cycle, the DNA of each chromosome is replicated so that it consists of two identical sister chromatids. In meiosis I, homologous chromosomes pair with each other and can exchange genetic material in a process called chromosomal crossover. The homologous chromosomes are then segregated into two new daughter cells, each containing half the number of chromosomes as the parent cell. At the end of meiosis I, sister chromatids remain attached and may differ from one another if crossing-over occurred. In meiosis II, the two cells produced during meiosis I divide again. Sister chromatids segregate from one another to produce four total daughter cells. These cells can mature into various types of gametes such as ova, sperm, spores, or pollen.Because the number of chromosomes is halved during meiosis, gametes can fuse (i.e. fertilization) to form a zygote with a complete chromosome count containing a combination of paternal and maternal chromosomes. Thus, meiosis and fertilization facilitate sexual reproduction with successive generations maintaining the same number of chromosomes. For example, a typical diploid human cell contains 23 pairs of chromosomes (46 total, half of maternal origin and half of paternal origin). Meiosis produces haploid gametes with one set of 23 chromosomes. When two gametes (an egg and a sperm) fuse, the resulting zygote is once again diploid, with the mother and father each contributing 23 chromosomes. This same pattern, but not the same number of chromosomes, occurs in all organisms that utilize meiosis. Thus, if a species has 30 chromosomes in its somatic cells, it will produce gametes with 15 chromosomes.
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