NET, IAS, State-SET (KSET, WBSET, MPSET, etc.), GATE, CUET, Olympiads etc.: Revision Terminology Part 20
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- Meiosis I = educational or heterotypic
- If Diplotene is long lasted = Dictotene in lamp brush chromosome, human female β end of 3rd mouth of prenatal life to 12 year arrested
- Separation of homologous chromosome = Disjunction (Anaphase I)
- Meiosis II β necessary as due to crossing over, chromatids are not identical & natural be separated spindles in meiosis II at right angle to that of meiosis I
- Meiosis II haploid no of chromosome present, crossing over during prophase β I, radon distribution of char in anaphase β I
- Meiosis βΎ cytological basis of MendelΥs law of inheritance
- Anaphase II β Centromere divides.
- Chromosome are carrier of MendelΥs factor.
- Each pair of factor β carried by homologous chromosome
- Each chromosome must carry factors.
- DNA duplication βΎ euchromatin
- In case translocation present in one of 2 sets of chromosome = translocation heterozygote β normal pairing into bivalents is not possible
- Hammerling β chromosome of individuals are controlled by nucleus
- Carmine stains nucleus.
- Hematoxylin stains chromosome
- Eukaryotes = DNA + histone (true chromosome) β protamine present
- A is linear ds DNA β Circular & joined at ends by polynucleotide ligase
- DNA molecule in tertiary helix & Supercoiled & them fit into vires.
- Bacterial chromosome = single ds DNA β Folded genomes β basic proteins, not histones β maintain stability in absence of member name.
- Even polyploidy = fertile
- Odd polyploidy = sterile
- Polyploidy disc by lutz β induced by colchicine βΎ gigantism octaploids usually die higher polyploidy
- Euploidy = exact multiple of haploid number.
- Aneuploidy = chromosome no which is not exact multiple of chromosome number.
- Monosomics isolated from diploids like tomato & maize.
- 21 monosomics isolated for hexaploid wheat.
- 21 nullisomics isolated for wheat
- (haploids of polyploidy = golyhaploids)
- Autopolyploids β some basic set of chromosome multiplied (autotriploid β sudleos watermelon, sugar beet, tomato, banana) .
- Polyploidy cell in otherwise diploid org = endopolyploidy.
- Size of chromosome β mitotic metaphase.
- Shape of chromosome β Anaphase
- Monocots contain larger chromosome than dicots
- Centromere β chromosome Movement during cell division
- Kinetochores β actual site of attachment of the spindle (in zea mays nulture)
- Metacentric β V β trillium & Tradescentia
- Sub metacentric β L
- Acrocentric β J
- Telocentric β I
- Arm ratio = (highest in acrocentric)
- Second constrictions are distinguish from primary as chromosome bends only in primary.
- Telomeres β Exhibit polarity & prevent union of chromosome ends with one another.
- Second Constriction involved in organization of nucleolus = nucleolus organizer region
- Histones H2A, H2B (lysine) , H3 & H4 arginine hold by H1 lysine rich linker.
- DNA content in pictograms.
- Most abundant form of chromatin in interphase nucleus.
- Ideogram β represent haploid set of organism in a series.
- Asymmetric Karyotype is an advanced feature over symmetric karyotype.
- Heterochromatin β Condensed, more deep stain, late replicating
- Euchromatin β expanded, less deep stain, early replicating or diffuse regions