Download App

Principles of Inheritance and Variation — BIOLOGY STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 ScienceBIOLOGYPrinciples of Inheritance and Variation5 Marks
Question
How does a chromosomal disorder differ from a Mendelian disorder?
✓

Answer

S. No.
Mendelian disorder
Chromosomal disorder
(i)
This disorder is mainly due to alteration or mutation in the single gene.
This disorder is caused due to absence or excess or abnormal arrangement of one or more chromosomes.
(ii)
This follows Mendel’s principles of inheritance.
This does not follow Mendel’s principles ofinheritance.
(iii)
This may be recessive or dominant in nature.
This is always dominant in nature.
(iv)
For example, haemophilia, sickle–cell anaemia.
For example, Turner’s syndrome.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Long Answer Type Questions [5M]" from Principles of Inheritance and Variation→Principles of Inheritance and Variation — all question types→BIOLOGY STD 12 Science question papers→Bihar Board STD 12 Science question papers→Bihar Board question paper generator→

Similar questions

Answer the following questions:
At which stage of life does gametogenesis begin in human male and female respectively?
→
Why are colour blindness and thalassemia categorised as Mendelian disorders? Write the symptoms of these diseases seen in people suffering from them.
→
Answer the following questions:
Explain the menstrual phase in a human female. State the levels of ovarian and pituitary hormones during this phase.
→
Give a genetic explanation for the following cross. When a tall pea plant with round seeds was crossed with a dwarf pea plant with wrinkled seeds then all the individual of F1-population were tall with round seeds. However selfing among F1-population led to a 9:3:3:1 phenotypic ratio.
→
Study the following flow chart. Name the hormones involved at each stage. Explain their functions.
→
List the attributes that populations but not individuals possess.
→
Describe the post-zygotic events leading to implantation and placenta formation in humans. Mention any two functions of placenta.

OR

  1. Briefly explain the events of fertilisation and implantation in an adult human female.
  2. Comment on the role of placenta as an endocrine gland.
→
Do you think that friends can influence one to take alcohol/drugs? If yes, how may one protect himself/herself from such an influence?
→
How did Meselson and Stahl experimentally prove that DNA replication is semiconservative? Explain.
→
An organism is able to survive on a culture medium, containing nutrient A, by the enzyme-catalysed reactions.
$\text{A}\xrightarrow{\ \ \ \text{p}\ \ \ }\text{B}\xrightarrow{\ \ \ \text{q}\ \ \ }\text{C}\xrightarrow{\ \ \ \text{r}\ \ \ }\text{D}$
A mutant organism failed to survive on this medium, but grew well when nutrient B was added to it.
  1. Which gene of this mutant organism is defective?
  2. What does such a condition indicate of ?
  3. Mention the major components and their functions in an operon.
  4. Indicate the value expressed in this sequence of reactions.
→