Biology Questions and Answers

(Greg DeLong) #1

Biology Questions and Answers


heterozygous there will be two different
genotypicalproportion. So forms, Aa aif a recessive pnd aa in the 1:1henotype
appears in the direct offspring the
parental individual that manifestsdominant phenotype is certainly
heterozygous.



  1. What is a genetic family
    tree?


Genetic family tree is a schematic family


tree that shinheritance ows the biologicalof some trait thro (^) ugh
successive generations.
Genetic family treit is practically impossible anes are useful becaused ethically
unacceptablcrossings for genetic testing be to make experimentaletween (^)
human beings. Wtress the study is made by analysisith the help of family of
marriages (and crossings) that have
already occurranalysis of family trees, for exampled in the past. From e,the
information on probabilities of the
emergence of some phenotype andgenotypes (including genetic diseases) (^)
in the offspring of a couple can be
obtained.



  1. What are the main
    conventional symbols and
    signs used in genetic family
    trees?


In genetic family trees the male sex is
usually represented by a square and thefemale by a circle. Crossings are
indicated by horizontal lines that


connect sqdirect offspring are listed buares to circles anelow andd their (^)
connected to that line. The presence of
the studiindicated bed phenotypicaly a complete hachure form is (^)
(shading) of the circle or the square
correspondent to thIt is useful to enumerate e affected individual.the individuals
from left to right and from top to
bottom for easy reference.



  1. What are the three main
    steps for a good study of a
    genetic family tree?
    Step 1: to determine whether thestudied phenotypical form has a
    dominant or recessive pattern. Step 2:


to identify recessive homozygousindividuals. Step 3: to identify the (^)
remaining genotypes.



  1. What is Mendel’s second
    law?
    Mendel’s second law postulates that two


or more different traits are alsoconditioned by two or more pair of (^)
different factors and that each inherited
pair separatesothers. In other words, gametes are independently from the
formed always with an aleatory
representative ofactors that determine phenotypicalf each pair of the (^)
characteristics.
Mendel’s second law is also knthe law of independent segregation oown asf (^)
factors, or assortment.law of independent
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