• Study Resource
  • Explore Categories
    • Arts & Humanities
    • Business
    • Engineering & Technology
    • Foreign Language
    • History
    • Math
    • Science
    • Social Science

    Top subcategories

    • Advanced Math
    • Algebra
    • Basic Math
    • Calculus
    • Geometry
    • Linear Algebra
    • Pre-Algebra
    • Pre-Calculus
    • Statistics And Probability
    • Trigonometry
    • other →

    Top subcategories

    • Astronomy
    • Astrophysics
    • Biology
    • Chemistry
    • Earth Science
    • Environmental Science
    • Health Science
    • Physics
    • other →

    Top subcategories

    • Anthropology
    • Law
    • Political Science
    • Psychology
    • Sociology
    • other →

    Top subcategories

    • Accounting
    • Economics
    • Finance
    • Management
    • other →

    Top subcategories

    • Aerospace Engineering
    • Bioengineering
    • Chemical Engineering
    • Civil Engineering
    • Computer Science
    • Electrical Engineering
    • Industrial Engineering
    • Mechanical Engineering
    • Web Design
    • other →

    Top subcategories

    • Architecture
    • Communications
    • English
    • Gender Studies
    • Music
    • Performing Arts
    • Philosophy
    • Religious Studies
    • Writing
    • other →

    Top subcategories

    • Ancient History
    • European History
    • US History
    • World History
    • other →

    Top subcategories

    • Croatian
    • Czech
    • Finnish
    • Greek
    • Hindi
    • Japanese
    • Korean
    • Persian
    • Swedish
    • Turkish
    • other →
 
Profile Documents Logout
Upload
Genetics Misconception on High School Textbook, the Impact and
Genetics Misconception on High School Textbook, the Impact and

... Misconceptions found as follows. Transcription is the process of DNA replication to form an RNA-d. Transcription is the process of transfer of genetic information from DNA segment (gene into mRNA molecules. The main material of polypeptide synthetic is gene. DNA requires intermediaries to bring mess ...
INSTRUCTIONS
INSTRUCTIONS

... source lactose so that the cell can use it for growth. Lac- cells cannot grow when lactose is the only carbon source, but can grow on minimal media plus glucose. You allow the bacteria to mate for certain time intervals, and then plate the mixture on four types of media that selects either for Met+, ...
RELATION BETWEEN HOMOZYGOUS VIABILITY AND
RELATION BETWEEN HOMOZYGOUS VIABILITY AND

... and the report of DOBZHANSKY and SPASSKY(1963) suggested that minimal heterozygous fitness is associated with chromosomes which are of intermediate homozygous subvitality. Such a curvilinear relationship is hard to study because of the correlation between counts of heterozygotes and homozygotes in t ...
Characterization of sex chromosomes in rainbow trout and coho
Characterization of sex chromosomes in rainbow trout and coho

... hybridization could correspond to the sex pair, since we need to demonstrate its chromosomal colocalization with OmyP9 probe. Studies of the distribution pattern of the 5S rDNA genes in the genome of salmonids indicates that these genes can occupy one or more loci (Pendás et al., 1994; Moran et al., ...
Effective transfer of chromosomes carrying leaf rust resistance
Effective transfer of chromosomes carrying leaf rust resistance

... was present in all hybrids examined (Fig. 1c, d). This consideration led us to suppose that triticale cv. Bogo and the F1 to BC2F5 hybrids of (Ae. tauschii × S. cereale) × triticale cv. Bogo could carry the dominant allele of the Ph1 gene. This assumption explained the appearance of 3D chromosomes i ...
Cell Energy and Cell Division Study Guide The test will consist of a
Cell Energy and Cell Division Study Guide The test will consist of a

... 45. Organisms that harvest energy from either sunlight or chemicals in order to make food molecules are called ____________________. 46. Following replication of its DNA, each chromosome contains two ____________________, which are attached to each other by a centromere. 47. The sequence of events t ...
Chapter 11 Complex Inheritance and Human Heredity
Chapter 11 Complex Inheritance and Human Heredity

... evaluated. The study of human genetics is difficult, because scien–tists are limited by time, ethics, and circumstances. For example, it takes decades for each generation to mature and then to have offspring when the study involves humans. Therefore, good record keeping, where it exists, helps scien ...
Chapter 11 and 12 from Campbell Biology 10th Edition By Keshara
Chapter 11 and 12 from Campbell Biology 10th Edition By Keshara

... to have r) X ½ (probability in sperm to have r)  so probability F2 plant in having wrinkled seeds is ¼ >to figure out that an F2 plant from a monohydric cross will be heterozygous rather than homozygous needs a 2nd rule  F1 gametes can combine to produce Rr offspring in two mutually exclusive ways ...
Document
Document

... Linkage and recombination—summary Genes on the same chromosome can show linkage instead of independent assortment Gametes (mostly) have the same allele combinations as the homologs in the parent Recombination can give rise to gametes with non-parental (i.e, recombinant) allele combinations Two pare ...
Study Guide - Tacoma Community College
Study Guide - Tacoma Community College

... permeability means, what types of molecules can pass through freely and which cannot, how those molecules pass through (diffusion, facilitated diffusion, active transport), other molecules associated with the membrane and the overall function of the membrane (why does the cell have one in the first ...
Reproduction in Organisms
Reproduction in Organisms

... are capable of regeneration into whole new plants. This type of reproduction is called vegetative reproduction. It may occur naturally or can be induced artificially. 10. Artificial methods of vegetative propagation have been developed by plant growers and horticulturists for commercial production ...
File
File

...  Cell division that leads to identical daughter cells  Cell division that leads to formation of sex cells ...
The dual nature of homologous recombination in plants
The dual nature of homologous recombination in plants

... random combinations of alleles and traits, which are subjected to natural selection and therefore contribute to the evolution of an organism. Meiosis is a key event in the life cycle of all sexually reproducing eukaryotic organisms, initiating the transition from the diploid to the haploid phase. Di ...
7.1 Chromosomes and Phenotype
7.1 Chromosomes and Phenotype

... What are the chances of getting an orange, male cat? 25% orange male cat What are the chances of a male cat being orange? 50% male orange cat What are the chances of a female being calico? ...
Identification of a Substituted Chromosome Pair in a Triticum
Identification of a Substituted Chromosome Pair in a Triticum

... random. At metaphase I, regularly 21 11 were obtained. Out of the 150 cells examined at diakinesis and metaphase I from 6 different plants, only 2 cells failed to show the normal configuration of 21". Both of these cells had 20" and 2 1• The association between the homologous chromosomes appeared to ...
Chromosome Research, 8:319-334
Chromosome Research, 8:319-334

... (Nakagawa et al. 1996). To characterize them more precisely, we used WCP probes to determine the frequency of cells that retained the human chromosome. As shown in Table 1, a relatively high percentage of rearrangements was found in the hybrids containing human chromosomes 1, 9, 10, 12, 20, 22, or X ...
Teacher quality grant - PAEC FloridaLearns Leadership
Teacher quality grant - PAEC FloridaLearns Leadership

... chromosomes with highlighted alleles  Phenotype - the physical _________ of the alleles  Genotype - allele __________ for a gene of an individual Bb, BB, or bb (B is the dominant allele, b is the recessive allele)  Trait - term for distinguishing phenotypic ...
The pelota locus encodes a protein required for meiotic cell division
The pelota locus encodes a protein required for meiotic cell division

... *Author of correspondence ...
Full Text
Full Text

... *Author of correspondence ...
Aberrant replication timing induces defective chromosome
Aberrant replication timing induces defective chromosome

... abnormal. Most frequently, mitotic chromosomes contained regions of undercondensed chromatin connected by normally condensed or even highly condensed chromatin, the same undercondensed region often visibly affected on both sister chromatids (Figure 3a, arrowheads). While the undercondensed chromatin ...
Chromosomal aberrations in oats, Avena sativa L
Chromosomal aberrations in oats, Avena sativa L

... genes seemed to segregate independently. The cultivated type of grain base was dominant to &e wild type and was independent of the color genes. The heterosygous plants in tibese advanced generations could be recognised by Ote kind of articulation of the lower grain. The interesting feature of titiis ...
Workbook - The Campion School
Workbook - The Campion School

... In this section, you are expected to know the chemical nature, general formulae and biological significance of DEFINITION A water molecule is described as being ...
unit 4 revision
unit 4 revision

... 1. Describe the DNA replication process. 2. When does replication occur in the life cycle of the cell? 3. Compare DNA replication and PCR by listing the similarities and differences between the two processes. 4. Why is meiosis significant to sexually reproducing organisms? 5. Compare Meiosis and Mit ...
15_detaillectout
15_detaillectout

... ? When Morgan crossed his white-eyed male with a red-eyed female, all the F1 offspring had red eyes, suggesting that the red allele was dominant to the white allele. ...
Reversing Chromatin Accessibility Differences that Distinguish
Reversing Chromatin Accessibility Differences that Distinguish

... Fig. 4 Visualization of internal chromosome accessibility with super resolution 3D-SIM. a Untreated metaphase cell showing DA between chromosome 17 homologs (left panel, circled) hybridized with single copy FISH probe within PMP22:IVS3 (2.32 kb). Probe depth spans 1.30 μm or 10 of 17 (middle panel, ...
< 1 ... 22 23 24 25 26 27 28 29 30 ... 431 >

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.
  • studyres.com © 2025
  • DMCA
  • Privacy
  • Terms
  • Report