PART - 2 - Unit V : CH - 18 Neural Control and Coordination — BIOLOGY STD 11 Science — Question

What is bone marrow? Briefly describe its types.

Amrita while playing with her friend, near the pond noticed in the pond that a green colour covering is floating on the surface of the water. She discussed this with her friend and both got surprised. Next day in the school Amrita asked her teacher about the same. Teacher told her, that was nothing, but green algae which occur both in fresh and marine water habitats.

1. Mention the economic importance of algae.
2. Why green algae are considered to be the ancestors of all land plants. Justify the statement by giving reasons.
3. What values as a good biology student are reflected from Amrita's character.

Write the scientific names of following organisms?

1. Cat.
2. Rose.
3. Sparrow.

By looking at a plant externally can you tell whether a plant is C₃ or C₄? Why and how?

Sumit, student of class XI when returned from school was told by his mother that his grandfather was complaining about some uneasiness. Sumit told his mother to take him to the doctor. The doctor tied a cuff around his arm and pumped air, then he slowly released the air. The handcuff was connected to a tube containing mercury. Doctor told Sumit that his grandfather is suffering from high blood pressure and put him on medication. The doctor also advised him to take precautions and rest and asked Sumit's mother to bring him for regular checkups.

1. What is meant by blood pressure?
2. What is the harmful effect of blood pressure on health?
3. Enumerate the range of normal and high blood pressure in human.
4. What values are displayed by Sumit as a good grandson?

Can there be mitosis without DNA replication in ‘S’ phase?

Eukaryotic cells have organelles which may
bound by a single membrane.
Group the various sub-cellular organelles into these categories.

State economically important uses of:
heterotrophic bacteria

Living beings are classified into different categories and sub-categories so that it becomes easy to study them. Which of the following shows similar theory? Give reasons for your answer. Moreover, mention the benefits of segregating students into different classes.

1. Students of a school are categorized into different classes and sections so that it becomes easy to manage them.
2. There are different departments in a schvol so that the school can function in a better way.
3. There are different teachers for different subjects so that a subject can be taught better.

Two groups (A and B) or bean plants of similar size and same leaf area were placed in identical conditions. Group A was exposed to light of wavelength 400-450nm and Group B to the light of wavelength of 500-550nm. Compare the photosynthetic rate of the two groups by giving reason.