Class 12 Biology - Chapter Principles of Inheritance and Variation NCERT Solutions | Explain the Law of Dominance using a mon
Explain the Law of Dominance using a monohybrid cross.
Mendel’s law of dominance states that a dominant allele expresses itself in a monohybrid cross and suppresses the expression of recessive allele. However, this recessive allele for a character is not lost and remains hidden or masked in the progenies of F1generation and reappears in the next generation.
For example, when pea plants with round seeds (RR) are crossed with plants with wrinkled seeds (rr), all seeds in F1 generation were found to be round (Rr). When these round seeds were self fertilized, both the round and wrinkled seeds appeared in F2 generation in 3: 1 ratio. Hence, in F1 generation, the dominant character (round seeds) appeared and the recessive character (wrinkled seeds) got suppressed, which reappeared in F2 generation.
More Questions From Class 12 Biology - Chapter Principles of Inheritance and Variation
- Q:- A child has blood group O. If the father has blood group A and mother blood group B, work out the genotypes of the parents and the possible genotypes of the other offsprings.
- Q:- A diploid organism is heterozygous for 4 loci, how many types of gametes can be produced?
- Q:-
Explain the following terms with example
(a) Co-dominance
(b) Incomplete dominance - Q:- Define and design a test − cross?
- Q:- When a cross in made between tall plants with yellow seeds (Ttyy) and tall plant with green seed (Ttyy), what proportions of phenotype in the offspring could be expected to be (a) Tall and green. (b) Dwarf and green.
- Q:- Briefly mention the contribution of T.H. Morgan in genetics.
- Q:- Mention any two autosomal genetic disorders with their symptoms.
- Q:- What is point mutation? Give one example.
- Q:- Differentiate between the following −
(a) Dominance and Recessive
(b) Homozygous and Heterozygous
(c) Monohybrid and Dihybrid. - Q:- Using a Punnett square, work out the distribution of phenotypic features in the first filial generation after a cross between a homozygous female and a heterozygous male for a single locus.
Popular Questions of Class 12 Biology
- Q:- Why is reproduction essential for organisms? Answer
- Q:- Name the parts of an angiosperm flower in which development of male and female gametophyte take place.
- Q:-
Fill in the blanks:
(a) Humans reproduce __________. (asexually/sexually)
(b) Humans are__________. (oviparous/viviparous/ovoviviparous)
(c) Fertilization is __________ in humans. (external/internal)
(d) Male and female gametes are __________. (diploid/haploid)
(e) Zygote is __________. (diploid/haploid)
(f) The process of release of the ovum from a mature follicle is called__________.
(g) Ovulation is induced by a hormone called the __________.
(h) The fusion of male and female gametes is called _____________.
(i) Fertilisation takes place in _____________.
(j) Zygote divides to form _____________which is implanted in uterus.
(k) The structure which provides vascular connection between fetus and uterus is called ____________. - Q:- What do you think is the significance of reproductive health in a society?
- Q:- Group the following as nitrogenous bases and nucleosides:
Adenine, Cytidine, Thymine, Guanosine, Uracil and Cytosine. - Q:- Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.
- Q:- What are the various public health measures, which you would suggest as safeguard against infectious diseases?
- Q:- Explain in brief the role of animal husbandry in human welfare.
- Q:- Bacteria cannot be seen with the naked eyes, but these can be seen with the help of a microscope. If you have to carry a sample from your home to your biology laboratory to demonstrate the presence of microbes under a microscope, which sample would you carry and why?
- Q:- Can you list 10 recombinant proteins which are used in medical practice? Find out where they are used as therapeutics (use the internet).
Recently Viewed Questions of Class 12 Biology
- Q:- What are the suggested reasons for population explosion?
- Q:- What is spermatogenesis? Briefly describe the process of spermatogenesis.
- Q:- Explain in brief the role of animal husbandry in human welfare.
- Q:- What initiatives were taken for reducing vehicular air pollution in Delhi? Has air quality improved in Delhi?
- Q:- Is sex education necessary in schools? Why?
- Q:- Fill in the blanks.
(a) Plants are called as_________ because they fix carbon dioxide.
(b) In an ecosystem dominated by trees, the pyramid (of numbers) is _________ type.
(c) In aquatic ecosystems, the limiting factor for the productivity is _________.
(d) Common detritivores in our ecosystem are_________.
(e) The major reservoir of carbon on earth is_________. - Q:-
Fill in the blanks:
(a) Humans reproduce __________. (asexually/sexually)
(b) Humans are__________. (oviparous/viviparous/ovoviviparous)
(c) Fertilization is __________ in humans. (external/internal)
(d) Male and female gametes are __________. (diploid/haploid)
(e) Zygote is __________. (diploid/haploid)
(f) The process of release of the ovum from a mature follicle is called__________.
(g) Ovulation is induced by a hormone called the __________.
(h) The fusion of male and female gametes is called _____________.
(i) Fertilisation takes place in _____________.
(j) Zygote divides to form _____________which is implanted in uterus.
(k) The structure which provides vascular connection between fetus and uterus is called ____________. - Q:- Define
(a) Juvenile phase
(b) Reproductive phase
(c) Senescent phase. - Q:- An orchid plant is growing on the branch of mango tree. How do you describe this interaction between the orchid and the mango tree?
- Q:- Offspring formed due to sexual reproduction have better chances of survival. Why? Is this statement always true?
10 Comment(s) on this Question
Most important biology class 12th supplementary paper
I understood... Thanks
Thanks, I understand it now
Wow this answer Is in very simple language.thank you very much saral study ðð
Thanks
Thank
I didn't understand
Satisfied thnx
I did not understand
its is an answer to dihybrid cross
- All Chapters Of Class 12 Biology
- All Subjects Of Class 12