Genetic Concepts
1. What is a gene?
2. Is a gene a triplet of
consecutive DNA nucleotides?
3. How is the concept of
chromosome related to the
concept of the gene?
4. What is meant by “gene
locus”?
5. What are alleles of a gene?
6. Are the alleles of a gene
necessarily originated one
from the father and the other
from the mother? Are there
exceptions?
7. What is a phenotype?
8. What is a genotype? What
is the difference between
genotype and phenotype?
9. Does the environment exert
an influence on the
phenotype?
10. Are environmental
phenotypical changes
transmitted to the offspring?
11. What are the situations in
which the environment can
alter the genotype of an
individual? What is the
condition for this type of
change to be transmitted to
the offspring?
12. What are some examples
of phenotypical characteristics
that present two or more
varieties and of phenotypical
features that do not vary? In
relation to the genes
correspondent to those
characteristics that vary
among individuals what can
be expected about their
alleles?
13. Considering a pair of
homologous chromosomes
containing a gene having two
different alleles how many
different genotypes can the
individual present?
14. For an individual having a
genotype formed of two
different alleles that condition
different varieties of the same
phenotypical trait, upon what
will the phenotypical feature
actually manifested depend?
15. What is the difference
between dominant allele and
recessive allele?
16. When ever a pair of alleles
has different alleles is there
dominance between them?
17. What is the difference
between homozygosity and
heterozygosity?
18. Why can it be said that a
recessive allele can remain
hidden in the phenotype of an
individual and revealed only
when manifested in
homozygosity in the
offspring?