Answer:
While some aspects of development may be strongly influenced by biology, environmental influences may also play a role. ... While the genetic instructions a child inherits from his parents may set out a road map for development, the environment can impact how these directions are expressed, shaped or event silenced.
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<span>Costly
Labor intensive
.Requires skilled person as selection is practiced
Pedigree record maintenance is time consuming
.<span>Selection for yield or other characters in F2 and F<span>3 </span>is ineffective.
</span><span>One important to note is genetic variation available for selection gets decreased in later generations due to the individual plant selection carried out earlier.
disadvantages
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Answer and Explanation:
<u>Available data</u>:
- S allele expresses sharp spines, and it is dominant
- s allele expresses dull spines, and it is recessive
- N allele expresses the presence of spines, and it is dominant
- n allele expresses the absence of the spines, and it is recessive
<u>Cross:</u> Doubly heterozygous SsNn individuals allowed to self-pollinate
Parental) SsNn x SsNn
Gametes) SN sN Sn sn / SN sN Sn sn
Punnet square) SN Sn sN sn
SN SSNN SSNn SsNN SsNn
Sn SSNn SSnn SsNn Ssnn
sN SsNN SsNn ssNN ssNn
sn SsNn Ssnn ssNn ssnn
- 9/16 individuals with sharped spines, S-N-
Their genotypic ratios are 1/16 SSNN, 2/16 SSNn, 2/16 SsNN, 4/16
SsNn
- 3/16 individuals with dull spines, ssN-
Their genotypic ratios are 1/16 ssNN and 2/16 ssNn
- 4/16 individuals with no spines at all, --nn
Their genotypic ratios are 1/16 SSnn, 2/16 Ssnn, and 1/16 ssnn.