Match the Following
Question Table
| Column A | Column B |
| 1. Growth of pollen tube towards ovule | a. Gravitropic movement |
| 2. Growth of shoot system | b. Chemotropic movement |
| 3. Growth of root system | c. Phototropic movement |
| 4. Growth towards water | d. Growth-irrelevant movement |
| e. Hydrotropic movement |
Answer Table
| Column A | Correct Match (Column B) |
| 1. Growth of pollen tube towards ovule | b. Chemotropic movement |
| 2. Growth of shoot system | c. Phototropic movement |
| 3. Growth of root system | a. Gravitropic movement |
| 4. Growth towards water | e. Hydrotropic movement |
2. Complete the paragraph.
The milk was on the stove. Rasika was engrossed watching television. She smelled something burning. She ran towards the kitchen. The milk was boiling over. She held the vessel with her bare hands but, screaming, she let it go at once. This activity was controlled by nerve cells. Special ends of dendrite in these cells collected the information, from where it was transferred to the cell body and then towards the terminal end of the axon. The chemicals produced at the terminal end passed through the minute space i.e. synapse. In this way, impulses were conducted in the body and the process of reflex action was completed by conducting the impulses from nerve to muscle cell.
3. Write notes on:
a. Root pressure
Root pressure is the force developed in the roots due to the absorption of water from the soil. It helps in pushing water upward through the xylem, especially at night or when transpiration is low.
b. Transpiration
Transpiration is the loss of water in the form of water vapor from the leaves through stomata. It helps in cooling the plant and in the upward movement of water.
c. Nerve cell
A nerve cell or neuron is the basic unit of the nervous system. It receives and transmits nerve impulses. It has three parts: dendrite, cell body, and axon.
d. Human brain
The human brain is the control center of the body. It controls thinking, memory, emotions, and body movements. It is protected by the skull.
e. Reflex action
Reflex action is an immediate and automatic response to a stimulus. It is controlled by the spinal cord and helps protect the body from harm.
4. Name the hormones of the following endocrine glands and the function of each.
a. Pituitary gland
Hormone: Growth hormone
Function: Controls growth and development of the body.
b. Thyroid gland
Hormone: Thyroxine
Function: Regulates metabolism and energy production.
c. Adrenal gland
Hormone: Adrenaline
Function: Helps the body respond to stress and emergency situations.
d. Thymus gland
Hormone: Thymosin
Function: Helps in the development of the immune system.
e. Testis
Hormone: Testosterone
Function: Controls male reproductive organs and secondary sexual characters.
f. Ovary
Hormones: Estrogen and Progesterone
Function: Control female reproductive organs and menstrual cycle.
6. Answer the following.
a. Explain chemical co-ordination in humans and give the names and functions of some hormones.
Chemical coordination in humans is carried out by hormones secreted by endocrine glands. Hormones travel through blood and regulate body functions. For example, insulin controls blood sugar, thyroxine regulates metabolism, and adrenaline prepares the body for emergencies.
b. Explain the difference between the excretory system of humans and plants.
Humans have a well-developed excretory system consisting of kidneys, ureters, bladder, and urethra. Plants do not have a special excretory system; they remove waste through leaves, bark, and roots.
c. Explain co-ordination in plants with the help of suitable examples.
Plants show coordination through hormones like auxins. For example, plants bend towards light due to auxin concentration on one side of the stem.
7. Explain in your own words with suitable examples.
a. What is meant by co-ordination?
Coordination is the process by which different organs work together to perform a function smoothly. For example, walking involves muscles, nerves, and the brain working together.
b. How does excretion occur in human beings?
Excretion in humans occurs through kidneys which filter blood and remove waste as urine. The urine is passed out through the urinary system.
c. How is excretion in plants useful to human beings?
Plants release oxygen and remove waste substances. Some plant wastes like resins and gums are useful to humans.
d. Describe the transportation system in plants.
Plants transport water and minerals through xylem and food through phloem. This system helps in growth and nourishment of the plant.