Name any two plants which flower only once in their life time after passing through a very long vegetative phase. |
OR |
How incompatibility acts as a natural barrier in the fusion of gametes? |
(i) Define brood parasitism in relation to birds. |
(ii) State Cause's "competitive exclusion principle". |
(i) In monohybrid cross of red and white flower, Mendel got only red flower. On setting the \[{{F}_{1}}\]plants having red flower he got both plants with red and white flower. Explain the basis of using RR and rr symbols to represent the genotype of plants of parental generation |
(ii) A, B, D are three independently assorting genes with their recessive alleles a, b, d, respectively. A cross was made between individuals of AabbDD genotype with aabbdd. Explain the type of genotypes of the offspring produced |
(iii) A progeny of \[{{F}_{1}}\] is crossed with the homozygous recessive parent. What is this cross called? Work out how is it useful? |
(i) What are the characteristic feautures of a true-breeding line? |
(ii) In peas, tallness is dominant over dwarfhess, and red colour of flowers is dominant over the white colour. When a tall plant bearing red flowers was pollinated by a dwarf plant bearing white flowers, the different phenotypic groups were obtained in the progeny in numbers mentioned against them. |
Tall, Red =138 |
Tall, White =132 |
Dwarf, Red =136 |
Dwarf, White =128 |
Mention the genotypes of the two parents and of the types of four off springs. |
(i) What is golden rice? |
(ii) What is gene therapy? Can it be used for treatment of sickle -cell anaemia, haemophilia and thalassemia? |
(i) What is vector? |
(ii) Name the two types of cloning vectors. |
(iii) Which cloning vector was discovered first time? |
Expain the following. |
(i) Phosphorus cycle |
(ii) Pyramid of energy. |
Discuss the following: |
(i) Chipko Movement |
(ii) Radioactive wastes. |
(i) Why can't O positive blood be tranfused into Nisha's body? |
(ii) What is the genetic basis of blood group inheritance? |
(iii) Human blood grouping is an example of. |
(iv) What values do you find in Nisha's brother and Ahmed? |
What develops into a microspore mother cell in a flower? Trace the development of this cell into a pollen grain which is ready for germination. |
OR |
A woman has conceived and implantation has occurred within her uterus. Describe the sequence of changes that would take place in her body up to parturition under the influence of various hormones. |
Write a note on Darwinism. How artificial selection is used to produce new varieties of crops? |
OR |
(i) Who coined the term 'genetic code'? What does it mean? |
One of the codons on mRNA is AUG Draw the structure of tRNA adapter molecule for this codon. Explain the uniqueness of this tRNA. |
How the role of plant tissue culture is useful in enhancing the food production? |
OR |
Name the causative organism, symptoms and mode of infection of typhoid and pneumonia. |
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