Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers


The vacuoles of protozoans are internal
structures sthat when necessary liberate pecialized in water water tostorage
the cytoplasm. Vacuoles thus can dilute
the cytoplasm foosmotic equilibrium with thr it to enter intoe
environment. Protozoans of fresh water


then need vacuoles mintracellular is hypertonic in ore sincrelation toe their (^)
the exterior. Without the dilution
mechanism prprotozoans of fresh water wovided by the vacuolould absorbes, (^)
too much water and would die.



  1. Do protozoans have sexual
    or asexual reproduction?


In protozoans reproduction is sexual or


asexual. The most fsexual reproduction is birequent form ofnary division, (^) or
scissiparity,itself by mitosis in which th originatine cell divig two des
daughter cells. Some species, like the
plasmodium, areproduce asexually bgent of malaria,y schizogony (^)
(multiple fission); in this form of
reproduction the cell becomesmultinucleated, generally inside (^) a host
cell, and each nucleus is expelled out
together with cytoplasm prise to new protozoans. ortions giving
The sexual rcan happen by conjugation, eproduction in protozoanswith
incorporation of genetic material from
one cell into athat fecundate otnother, or by gameteshers and form zygotes. (^)
In the plasmodium sexual reproduction
happens in the mosqhost, and the zygote undergoes mitosisuito, the definitive (^)
(sporogony) creating many sporozoites.



  1. Which is the form of
    protozoan reproduction that
    generates more variability?
    Sexual remore genetic variabilityproduction always g than asexeneratesual
    reproduction.reproduction the fusion of genetic That is because in sexual
    material from different individuals
    occurs ageneticallynd so the offspring is not identical to the parent cell.


If the hypothesisoriginated multicellular a that protozoansnimals is (^)
strong, other hypotheses may bstronger: that these protozoans we evenere
able to reproduce sexually, since only
genetic variationdifferentiation to the can produce biologicalpoint of creating
new types of living beings.



  1. What are the four groups
    of protozoans?
    The four main groups of protozoans are
    the sarcodinlike amoebae), the mastigophes (that form pseudopods,ores
    (flagellated, like the trypanosome that
    causes C(like paramecia) and the sporozhagas’ disease), the ciliatedoans
    (spore-forming, like plasmodia).

  2. Why are euglenas involved
    in polemics related to their
    taxonomic classification?
    Euglenas are involved in taxonomic


polemicsclassified som because they tend to beetimes as protozoans an (^) d
sometimes as algae. Although they have
chloroplasts and they are photosynthetic
http://www.biology-questions-and-answers.com

Free download pdf