Molecular Basis Of Inheritance

Step 1: General formula of carbohydrates.
Most carbohydrates follow the general formula (CH O) .
Step 2: Exception to the rule.
Some carbohydrates contain modified groups and do not strictly follow this formula.
Step 3: Identifying rhamnose.
Rhamnose is a deoxy sugar in which one hydroxyl group is replaced by hydrogen.
Step 4: Conclusion.
Thus, rhamnose is a carbohydrate that does not follow the general formula.

Step 1: Understanding nitrogenous waste excretion.
Animals excrete nitrogenous wastes in different forms depending on their habitat and water availability.
Step 2: Types of excretion.
Ammonotelic animals excrete ammonia and require more water.
Ureotelic animals excrete urea and require moderate water.
Uricotelic animals excrete uric acid and conserve maximum water.
Step 3: Identifying the animal.
Lizard is a uricotelic animal and excretes uric acid as semi-solid paste.
Step 4: Conclusion.
Therefore, lizard is a better conserver of water.

Step 1: Structure of stamen.
A stamen consists of a filament and an anther. The anther has two lobes connected internally.

Step 2: Identifying the connecting part.
The filament attaches to the anther through a tissue called the connective.

Step 3: Conclusion.
Hence, the filament is attached to the anther by the connective.

Step 1: Understanding translation in protein synthesis.
Translation is the process by which the genetic code present on mRNA is decoded to form a polypeptide chain. This process takes place on ribosomes in the cytoplasm.

Step 2: Role of different molecules.
m-RNA: It carries the genetic code from DNA to ribosomes and acts as a template during translation.
r-RNA: It forms the structural and catalytic core of ribosomes, essential for peptide bond formation.
t-RNA: It brings specific amino acids to the ribosome according to the codon on mRNA.
DNA: DNA is involved in transcription, not directly in translation. Hence, it is not required during translation.

Step 3: Conclusion.
Since DNA does not directly participate in translation, the correct answer is (B) DNA.

Step 1: Understanding epiphyllous buds.
Epiphyllous buds are adventitious buds that develop on the margins or surface of leaves and help in vegetative propagation.
Step 2: Analyzing the options.
(A) Oxalis: Correct — Oxalis propagates mainly by underground structures like bulbs or rhizomes, not by epiphyllous buds.
(B) Kalanchoe: Incorrect — It propagates through epiphyllous buds formed along leaf margins.
(C) Bryophyllum: Incorrect — It is a classic example of propagation through epiphyllous buds on leaves.
(D) Begonia: Incorrect — Begonia can also propagate vegetatively through leaf buds.
Step 3: Conclusion.
The plant that does not propagate by epiphyllous buds is (A) Oxalis.

Step 1: Understanding memory centers.
Memory, intelligence, learning, and conscious activities are controlled mainly by the cerebrum.
Step 2: Role of telencephalon.
The telencephalon forms the cerebrum, which contains the cerebral cortex and hippocampus—both essential for memory formation and recall.
Step 3: Analysis of options.
(A) Rhombencephalon: Controls respiration and balance.
(B) Rhinencephalon: Associated mainly with olfaction.
(C) Telencephalon: Correct — responsible for memory and higher functions.
(D) Mesencephalon: Involved in visual and auditory reflexes.
Step 4: Conclusion.
Loss of memory indicates injury to the telencephalon.

Step 1: Understanding auricle structure.
The auricle or pinna helps in collecting sound waves and directing them into the auditory canal.
Step 2: Type of cartilage.
Elastic cartilage provides flexibility and maintains the shape of the external ear.
Step 3: Conclusion.
Therefore, the auricle is made up of elastic cartilage.

Step 1: Understanding polygenic inheritance.
Human skin colour is controlled by three pairs of polygenes showing additive effect.
Step 2: Calculations.
Number of gametes =
Total combinations in F =
Number of phenotypes =
Step 3: Conclusion.
Thus, the correct matching is 8, 64, 7.