SOLUTIONS- (d) : From the given pedigree analysis, it can be determined
that the trait in concern is neither X-linked recessive nor
only autosomal recessive (as should not have expressed
itself in last generation). It cannot be sex limited as well
because both male and female show the concerned trait.
The trait therefore seems to be influenced by some factors.
It can be sex influenced trait. Sex influenced traits are
autosomal traits that are expressed based on the influence
of the sex, in particular the sex hormones. Although these
traits can be seen in both the sexes, the degree or frequency
of the phenotypic expression varies according to the sex.
For example baldness pattern in humans. The presence
of hair as a character has 2 forms: baldness (B+) and full
hair (B–). B+ is dominant in males but recessive in females
and, hence, requires 2 B+ to cause baldness in females. In
addition, the presence of testosterone levels influences the
expression of baldness allele. Higher levels of testosterone
hormone in males cause the baldness gene to be dominant
while lower levels in females make it recessive. This trait is
also called as male pattern baldness.
Genotype Male Female
B+B+ Bald Bald
B+ B– Bald Full hair
B– B– Full hair Full hair - (b)
- (c) : During telophase, the nuclear envelope reappears
around chromatin and nucleoplasm. It is formed from either
pieces of older nuclear envelope or endoplasmic reticulum.
Therefore, ER contributes towards formation of nuclear
envelope.
After few hours, the seedlings were subjected to
autoradiography. What would be the result?
(a)Seedling A Seedling B(b)Seedling A Seedling B(c)Seedling A Seedling B(d)Seedling A Seedling B
(INBO 2014)- Which of the following pairs is mismatched?
(a) Spliceosome - Removal of introns
(b) Transposase - Insertion of DNA segments into
DNA
(c) DNA polymerase - Makes a molecule of DNA from
a DNA template
(d) RNA polymerase - Makes a molecule of RNA from
an RNA template
(NSEB 2013-14) - In a plant, genes A, B and C control the flower colour, height
and position of the flowers respectively. Study the following
genotypes and corresponding phenotypes :
AA → red flower
aa → white flower
Aa → pink flower
B → tall plant
bb → dwarf plant
C → axillary flower and
cc → terminal flower
If AabbCC and aaBbCc are crossed, what proportion of
plants would be tall, have pink and axillary flowers in the
progeny?
(a) 25% (b) 50%
(c) 75% (d) 100% (INBO 2013)
Send your response at [email protected] or post to us with complete address by 25th of
every month to win exciting prizes. Winner’s name will be published in next issue.- Make as many biological terms as possible
using the given letters. Each word should
contain the letter given in circle. - Minimum 4 letter word should be made.
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many times as it appears in the box. - Make at least 1 seven letter word.
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