Selina solutions for Concise Biology [English] Class 10 ICSE chapter 7 - Chemical Coordination in Plants [Latest edition]

The only phytohormone which is a gas at ordinary temperature:

The hormone which promotes the ripening of fruits is ______.

A growth inhibiting hormone in plants:

The hormone which stimulates cell division:

Development of fruits without fertilisation is called ______.

The response by parts of the plant towards stimulus is called as ______.

Apical dominance is influenced by ______.

The growth movement of plant parts which occurs due to touch stimulus is called ______.

The instrument which can be used to demonstrate geotropism is ______.

The hormone which accelerates senescence (ageing) and abscission of leaves is ______.

Match the items in column A with those of column B.

Growth of root towards water is ______.

______ hormone inhibits apical dominance.

______ and ______ induce chemotropism of angiosperms and gymnosperms.

______ of sweet peas exhibit thigmotropism.

______ is also called as "stress hormone''.

How is movement in plants different from that in animals?

Name the stimulus which causes the following movement in plant:

phototropism

Name the stimulus which causes the following movement in plant:

Thigmotropism

Name the stimulus which causes the following movement in plant:

Hydrotropism

Name the stimulus which causes the following movement in plant:

Geotropism

Name the following:

Hormone that stimulates growth by cell division.

Name the following:

Growth-retarding hormone in plants.

Name the following:

The main auxin found in most plants.

Define the following term:

Phytohormones

Define the following term:

Tropism

Define the following term:

Clinostat

Define the following term:

Apical dominance

Define the following term:

Parthenocarpy

Define the following term:

Abscission

Define the following term:

Heliotropism

List five plant growth hormones and briefly describe their roles.

Differentiate between:

Thigmotropism and geotropism

Differentiate between:

Positive and negative tropism

Differentiate between:

Stimulus and response

Differentiate between: 

Phototropism and chemotropism

The tea plants are never allowed to grow lengthwise. This is done by cutting their apical buds, a process known as pruning. In this way, tea plants get a dense growth and easy yield. Answer the following questions:

1. Name the scientific phenomenon that is being overcome by pruning.
2. What plant hormone is responsible for the scientific phenomenon mentioned in (a)?
3. Name one plant hormone which inhibits the said phenomenon.

The figure given below shows the stages of ripening in a banana. Answer the questions that follow:

1. Name the plant hormone responsible for the above changes.
2. Mention two characteristic features of this hormone.

The diagram given alongside shows a type of tropism. Study the same and answer the questions that follow:

1. Name and define the type of tropism shown in the diagram.
2. Label the guidelines (1) to (4).
3. Name two effective stimulants that help in the growth of part (2). 
4. Name two groups of plants where part (2) grows towards gametophyte with the help of the stimulants mentioned in (c).

Study the diagrams given below and answer the following questions:

1. Name the structures shown as X and Y in the figures (A) and (B), respectively.
2. Write the functions performed by the structures X and Y.
3. Name the phenomenon depicted and define it.
4. How do the structures X and Y differ from each other?
5. Give examples of the plants which show the said phenomenon.

Given below are the figures showing some kinds of tropic movements in plants. Study the same and answer the following questions:

1. Which one of these figures is correct? Give reason in support of your answer.
2. Name the kinds of movements shown by the root system and shoot system. Define each.
3. What are the two stimuli which affect root system and shoot system positively? Name them.
4. Which of the following stimuli affects the growth of the root strongly?
   1. Gravity
   2. Water
5. Draw a neat and labelled diagram of the longitudinal section of a pistil showing chemotropism in an angiospermic plant.

The box given below contains twelve words. Out of these, ten can be arranged in five suitable matching pairs. Make these five pairs in the form of a table.

The figure given below depicts a kind of tropic movement in plants. Study the same and answer the following questions:

1. What kind of a movement is shown in the figure? Define it.
2. How does this movement differ from geotropism?
3. Name the stimulus responsible for thigmotropism. Give one example of a plant showing thigmotropism.
4. Name one stimulus which gives a positive response for the roots but a negative response for the shoot.
5. Draw a neat and labelled diagram of the part of a plant showing leaf tendril. Name the plant.