Q1: Which part of nervous system controls reflex arc?
Answer: Spinal Cord
Q2: Which tropic movement is responsible for the growth of pollen tube towards ovules?
Answer: Chemotropism
Q3: Why endocrine glands release their secretion into the blood?
Answer: Because endocrine glands is ductless.
Q4: At the age of puberty, both boys and girls show lots of changes in appearance. Name the hormones responsible for these changes?
Answer: Testosterone in male and oestrogen in female.
Q5: Which system facilitates the communication between central nervous system and other parts of the body?
Answer: Endocrine system
Q6: Which gland secretes growth hormone in human beings?
Answer: Pituitary Gland
Q7: Which mechanism control timing and amount of hormone released?
Answer: Feedback mechanism
Q8: Define chemotropism?
Answer: Chemotropism is a kind of tropic movement in which plants move in realtion to chemical.
Q9: What are hormones?
Answer: Hormones are the chemical substance secreted by the gland.
Q10: Name two tissues that provide control and coordination in multicellular animal?
Answer: Nervous tissues and endocrine tissues
Q11: Define the term hydrotropism?
Answer: Chemotropism is a kind of tropic movement in which plants move in realtion to water.
Q12: Define the term geotropism?
Answer: Geotropism is a kind of tropic movement in which plants move in realtion to gravity.
Q13: Define the term phototropism?
Answer: Phototropism is a kind of tropic movement in which plants move towards light stimulus.
Q14: Define reflex action?
Answer: Reflex action is a sudden, involuntary movement response to the stimulus that is usually helpful to protect ourselves from any kind of harm.
Q15: Give one example of chemotropism?
Answer: The growth of pollen tube towards ovule.
Q16: Name the largest cell in the human body.
Answer: Nerve cell (Neuron).
Q17: What are plant hormones?
Answer: The chemical substances produced in plants which help in the growth and development of plant, its tissues and other plants.
Q18: Name the part of neuron
(а) where information is acquired.
(b) through which information travels an electrical impulse.
Answer: (a) Dendrite
(b) Axon
Q19: Name two tissues that provide control and coordination in multicellular animals.
Answer: Muscular tissues and nervous tissue.
Q20: Name the hormone, the secretion of which is responsible for dramatic changes in appearance in girls and boys when they approach 10-12 years of age.
Answer: Boys -> Testosterone and Girls -> Estrogen
Q21: Name the hormone that helps in regulating level of sugar in our blood. Name the glands that secretes it.
Answer: Insulin hormone secreted by pancreas.
Q22: A potted plant is made to lie horizontally on the ground. Which part of the plant will show:
(i) Positive geotropism
(ii) Negative geotropism
Answer: (i) Roots will shows positive geotropism, (ii) Shoots will shows negative geotropism.
Q23: Name a plant hormone which promotes growth in plants.
Answer: Auxin
Q24: What are meninges?
Answer: Meninges are the three membranes which cover the brain to protect it.
Q25: How do we detect smell of hot spicy food from a distance?
Answer: We detect smell of hot spicy food from a distance with the help of olfactory receptors.
Q26: How are the brain and spinal cord protected from mechanical shock?
Answer: Brain is present in a bony box called cranium (skull), spinal cord is protected by vertebral column.
Q27: Which functions are regulated by the forebrain?
Answer: Functions which are regulated by the forebrain are:
(i) Movement of voluntary muscles
(ii) Hearing, smell, sight, hunger, thirst, pain, etc. by its association areas
(iii) It also stores information and controls intelligence
Q28: How are sensory neurons different from motor neurons?
Answer: Sensory neurons:- It takes information from receptors and transmit the impulses towards central nervous system.
Moter neurons:- It carries messages from control nervous system to the muscle, gland or an organ to enable it to respond.
Q29: How are receptors different from effectors?
Answer: Receptors:- Receptors are cells, tissues or organs which receive the information in form of stimulus.
Effectors:- Effectors are muscles, glands tissues or cells which respond according to the information received through motor neuron from the central nervous system.
Q30: Label the parts of a neuron in figure given below.
Answer: (a) Dendrite, (b) Cell Body, (c) Axon, (d) Nerve ending
Q31: Lable the parts (a), (b), (c) and (d) and show the direction of flow of electrical signals in the given figure.
Answer: (a) Sensory neuron, (b) Spinal cord (part of CNS), (c) Motor neuron, (d) Effector (Muscle)
Q32: How does feedback mechanism regulate the hormone action? Explain with the help of an example.
Answer: The feedback mechanism regulates the amount and the timing of hormone to be secreted. For example, if the sugar level of a person in blood rises, it is detected by the cells of the pancreas which respond by producing more insulin. Thus the blood sugar level falls, and insulin secretion is reduced.
Q33: What are the different types of neurons and their functions in the human body?
Answer:
Sensory neuron: They transmit information from receptors towards the central nervous system.
Motor neuron: They transmit information from the central nervous system to effectors like muscles or glands.
Q34: What is a tropic movement?
Answer: The directional movements caused in plants due to an external stimuli are called tropic movements.
Q35: What will happen if intake of iodine in our diet is low?
Answer: Due to low level of iodine in diet might result is a disease called goitre in the person because iodine supports in the synthesis of thyroxin hormone from thyroid gland. Thyroxin hormone is necessary for digestion of carbohydrate, proteins, fat and metabolism.
