Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers



  1. What are the primary and
    the secondary constrictions of
    a chromosome? What is the
    other name given to the
    secondary constriction?


Primary constrictionregion of a condensed chrom is the narrowosomeer
where the centromere, the structure


that unites idlocated. Secoenticalndary co chromatids, isnstriction is a (^)
region similar to the primary
constriction, narrthickness of the chromosome ower than the normaltoo, and
in general it is related to genes that
coordinate nucleolus and control ththe formation e ribosomicof the (^) RNA
(rRNA) synthesis. For this reason the
secondary coor more in chromosomntrictions (that can e) is calledbe one
nucleolus organizer region (NOR).



  1. What are homologous
    chromosomes? Which are the
    human cells that do not have
    homologous chromosomes?


Chromosominformation es contain gin the form of nucleotideenes (genetic


sequences) tsynthesis thus regulating hat command the proteinand controllin (^) g
the activitiesof somatic cells of diploid beings every of the cell. In the nucleus
chromosome has its correspondent
homologous chcontaining alleles of romosome, the same gboth (^) enes
related to same functions. This occurs
because comes from the father one chromosome and the otherof one pair
comes from the mother of the
individual. a pair with allelThe chromes of the same gosomes that fenes areorm (^)
called homologous chromosomes. In
humans, there are 22 pairs of
homologous chof sex chromosomromosomes pes (the sexlus the pair
chromosomes are partially
homologous).
The only human cells that do not have
homologous chgametes since during meiosis theromosomes are the
homologous chromosomes are
separated.



  1. What is the difference
    between the concepts of
    karyotype and genome?


Genome is the set of DNA molecthat characterizes each living being orules (^)
each species. The concept then includes
the specific nucleotide sDNA molecules of each individual oequence of ther
species. Karyotype is the set of
chromosomes oindividual or species concerf individuals oningf a given
morphology and number of each
chromosome or pair of homologous.



  1. Can two normal
    individuals of the same
    species with sexual
    reproduction have identical
    genomes and identical
    karyotypes? How is the human
    karyotype usually
    represented?


Except ffrom nucleus traor clones (individuals creatensplantation, like thde (^)
Dolly sheep) and monozygotic twins, it
is very improbable the genomes of twoindividuals of the same species and
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