Ans. Mendels law of Inheritance-Based on his hybridisa- tion experiments, mendel proposed the law of Inheritance.
(i) Law of Dominance (Ist Law)-This law states that when two alternative forms of a trait or character (gene or alleles) are present in an organism. Only one factor expresses its self in F progeny and is called dominant while that remains called Recessive. (i) Law of Segregation (Second Law)-This law states that the factor or alleles of a pair segregate from each other during gamete formation such that a gamete receive only one of the two factors. They do not show any blending.
(iii) Law of Independent Assortment-According to this law when two pairs of traits are combined in a hybrid, seggregation of one pair of traits is independent of the other pair of traits.
Question 2. Differentiate between DNA and RNA.
Ans. Difference between DNA and RNA :
Question 3. What do you mean by Incomplete Dominance? Explain with suitable example.
Ans. Incomplete dominance Incomplete dominance was discovered by corners. "It is the phenomenon of neither of the two alleles of a gene being dominant over each other so that when both of them are present together, a new phenotype is formed which is some what intermediate between the independent expression of the two alleles. Example:
Question 4. What is gene mutation? What is its role in organic evolution?
Ans. Sudden heritable change in the chemistry of gene is known as gene mutation. They play major role in variation which is favoured by nature and lead to evolution of new species.
Question 5. Name any two enzymes of DNA replication and mention one specific function of each of them.
Ans. Two enzyme of DNA replication is Helicase and DNA polymerase III. Hellcase Uses the hydrolysis of ATP of 'Unzip' or unwind the DNA helix at the replication fork to allow the resulting single strands to be copied. DNA Polymerase III-In charge of synthesizing nucleotides onto the leading end in the 5' to 3' direction.
Question 6. What do you understand by the following ? [BSEB, 2014] 0
(a) Micro Mutation (b) Macro Mutation (c) Chromosomal Mutation
Ans. (a) Micro-mutation-It is also called point mutation or single base mutation. It is a type of mutation that causes the replacement of a single base nucleotide with another nucleotide of genetic material, DNA or RNA.
(b) Macro-mutation-A mutation that has a profound effect on the resulting organism, as a change in a regulatory gene that controls the expression of many structure genes.
(c) Cromosomal mutation-Any event that changes genetic structure any alteration in the inherited nucleotic acid sequences of the genotype of an organism. Name the eros.
7. What is Geological time Sacle? It is classified into eros.
Ans. Geological time scale GTS is chronological measurement that relates stratigraphy to time, and is used by geologists, paleontologists, and other earth scientist to describe the timing and relationships between events that have occurred throughout earth's history.
The name of eras are following:
(i) Cenozoic
(ii) Mesozoic
(iii) Paleozoic
(iv) Neo-proterozoic
(v) Meso- proterozoic
(vi) Paleo-proterozoic.
Question 8. What is the effect of mutation on protein synthesis?
Ans. Mutagenic factors such as ultraviolet rays, under the influence of X-rays and chemicals, some changes take place in the carriers of nucleic acids. These also affect protein synthesis, because the structure of proteins depends on the amino acid sequence, which in turn depends on the sequence of the m-RNA carriers, the RNA's carrier sequence, ultimately on the bank sequence in DNA. If the base is destroyed, then it may happen. This may result in the entire sequence of the bar being broken and a completely different type of protein being formed. The mutation is called frameshift mutation. On the contrary, sometimes there is no change in the holder. Despite this, there is no difference in the amino acid sequence of the protein because it is located on the nasar bark of the triplet tendon, so that the E-RNA and amino acid interactions.
Question 9. What is point mutation? Give one example.
Ans. It is the abrupt change in gene structure due to change in a single base pair of DNA due to inversion and substitution, without changing the reading of subsequent bases. A classical example of such mutation is sickle cell anaemia. In this there is a single base change at the chain of
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