ISC (Science) ISC Class 12 - CISCE Important Questions

Which one of the following choices reflects the correct number of chromosomes in the zygote and in the second polar body of Drosophila melanogaster?

All STDs do not affect the genital organs. Justify the statement.

The genotype of a person withTumer's syndrome will be:
(i)   44+XXY
(ii)  44+XYY
(iii) 44+XO
(iv) 44+XXYY

Choose the correct options of the following question:

Study the given monohybrid cross:

A test cross for this Fj will be:

Define the Homologous chromosomes

A homozygous pea plant with round seed coat and yellow cotyledons are crossed with another homozygous, pea plant having wrinkled seed coat and green cotyledons.

1. Give the types of gametes produced by plants of F-generation.
2. Give the dihybrid phenotypic ratio with the corresponding phenotypes.
3. State Mendel’s principle involved in this cross.

Mention one cause for variation in nature.

Explain the process of sex determination in honey bees.

Give an account of artificial chromosomes in the transfer of genetic material.

What is the genotype of Turner's Syndrome?

Mention any one symptom of Turner's syndrome.

A haemophilic man marries a carrier woman and they have a daughter. What is the probability of their daughter being haemophilic?

In a karyotype analysis, X and Y chromosomes represent sex chromosomes.

Name the scientist who discovered the X chromosome.

Jacob is genetically a carrier of the disorder that affects the shape of the RBCs, as shown in the diagram below. His son James suffers from the same disorder.

1. Give the biochemical reason for the disorder that changes the shape of the RBCs, as shown above.
2. Draw a Punnett square to show the genotype of the mother of James.
3. Name and define the type of 'point mutation' responsible for this disorder.

Consider the following information and answer the question that follows:

Make a single pedigree chart using the above information to show the pattern of inheritance of phenylketonuria (PKU) in the family of Reshma.

What are introns?

Transcription is the transfer of genetic code from a DNA molecule to ______.

Initiation codon of protein synthesis in Eukaryotes is ______.

Give one significant contribution to the following scientists:

Sanger

What is the central dogma?