Animal Kingdom — BIOLOGY STD 11 Science — Question

Distinguish between chloroplast arid chromoplast (any three).

What is the natural source of auxin? Write any four differences between auxin and gibberellin.

What is the general structure of Bryophytes?

While teaching cell division in the class, teacher told that during meiosis, the chromosome number is reduced to half of the parent, whereas during mitosis, the number remains the same. Seema was not able to recognise what teacher explained in the class and asked her elder brother, a botany student, the need of reducing chromosomes during gamete formation and what will happen if chromosome number will not reduced to its half. He explained the concept in detail to Seema.

1. In which part of the organisms does meiosis occur?
2. How does meiosis help in evolution?
3. Give the significance of meiosis.
4. What value is expressed in the behaviour of Seema's elder brother?

Explain arithmetic growth in plants.

Enlist the functions of polysaccharides.

Deciduous plants shed their leaves during hot summer or autumn. This process of shedding of leaves is called abscission. Apart from physiological changes, what anatomical mechanism is involved in the abscission of leaves?

Explain how hypothalamus functions as an endocrine gland?

What are the criteria used to classify fungi?

Class XI biology students attended a seminar where the speaker explained the students about the basic macromolecule found in the body, i.e., protein. He started with the monomer unit of protein and explained about different amino acids found. As amino acids are organic compounds containing an amino group and an acidic group as substituents on the same carbon; they are also considered as substituted methane. Suddenly, Ajay stood up and asked about his queries based on the topic. The guest of seminar patiently explained him all the things. Ajay became satisfied and returned home happily from the seminar.

1. What are the four substituent groups in an amino acid?
2. Why are there so many different types of amino acids?
3. Give the general formula of a-amino acids.
4. Indicate the value of Ajay reflected from the above topic.