Genetics And Evolution

- The laws of India permit legal adoption, making it one of the best options for childless couples. - However, emotional, religious, and social factors often act as deterrents to the adoption of children, especially in conservative settings.

Explanation: Phosphodiester bonds connect the phosphate group of one nucleotide to the sugar of another, forming the backbone of a polynucleotide chain.
This bond is known as an N-glycosidic linkage. It connects the 1' carbon of the pentose sugar to the nitrogen atom of the nitrogenous base.
Other bonds in the polynucleotide structure:
Phosphodiester bond: Links the sugar molecules of adjacent nucleotides. Hydrogen bond: Occurs between complementary nitrogenous bases in double-stranded DNA.
Peptide bond: Found in proteins, not in polynucleotides.

To find the minimum number of base combinations needed to code for 96 distinct amino acids, we can apply the formula for the number of possible combinations: In this case: - There are 12 different base types in DNA. - We need to determine how many bases per codon are necessary to produce at least 96 different amino acids. Let represent the number of bases required per codon. The total number of possible codons will be , and we want this value to be at least 96. Now, calculating the powers of 12: - - Since exceeds 96, the minimum number of bases per codon required is 2. Thus, the correct answer is . Option (A): Incorrect. would result in a much higher number than necessary.
Option (B): Incorrect. provides more than 96 codons, and 3 bases per codon is unnecessary.
Option (C): Correct. The minimum number of bases per codon is 2, as exceeds 96.
Option (D): Incorrect. Using 4 bases per codon would create far more combinations than needed, but 2 bases is the minimum required.

(A) 45 + XX: This refers to Down Syndrome, which is characterized by distinct physical traits such as broad palms and palm creases.
(B) 44 + XXY: Incorrect. This karyotype represents Klinefelter Syndrome, which affects males and results in partial masculine development, not feminine characteristics.
(C) 44 + XO: This refers to Turner Syndrome, where females are infertile due to underdeveloped ovaries.
(D) 44 + XY: This corresponds to normal males.

Flowering plants have developed the following devices to encourage cross-pollination: Dichogamy: Temporal separation of male and female reproductive organ maturity (e.g., protandry in sunflower). Self-incompatibility: Genetic mechanism that prevents self-pollen germination (e.g., Brassica). Herkogamy: Physical barrier between male and female organs to prevent self-pollination (e.g., hibiscus). Monoecy and Dioecy: Separation of male and female flowers on the same or different plants (e.g., maize and papaya).