A thorough understanding of Kerala Syllabus 9th Standard Biology Notes Pdf Chapter 4 Behind Movements Extra Questions and Answers can improve academic performance.
Kerala Syllabus Std 9 Biology Chapter 4 Behind Movements Extra Questions and Answers
Question 1.
Plants absorb water from the soil through their roots. Which kind of movement facilitates this?
Answer:
Osmosis (It is the natural movement of water molecules from a region of higher concentration to a region of lower concentration through a semi-permeable membrane. In the case of plants, water moves from the soil into root hair cells through osmosis).
Question 2.
How do amoebas move?
Answer:
Amoebas are single-celled organisms that move using a process called amoeboid movement. They extend temporary projections called pseudopodia, which anchor to the substrate and pull the rest of the cell forward.
Question 3.
What is the role of cilia and flagella in movement?
Answer:
Cilia and flagella are hair-like structures found on the surface of cells. They play a crucial role in movement:
- Cilia: Short, hair-like structures that beat in a coordinated manner to propel cells or substances. They are found in the respiratory tract to move mucus and particles.
- Flagella: Longer, whip-like structures that rotate to propel cells. They are found in sperm cells and some bacteria.
Question 4.
Identify the word pair relationship and fill in the missing word.
a. Skeletal Muscle: Voluntary:: Cardiac Muscle: …………
b. Actin: Thin filament:: Myosin: …………
Answer:
a. Involuntary
b. Thick filament
Question 5.
The movement of sperm cells is an example of ——– movement.
Answer:
Flagellar movement
Question 6.
The type of muscle found in the walls of the heart is called ———- muscle.
Answer:
Cardiac muscle
Question 7.
What is the role of tendons in muscle movement?
Answer:
Tendons are important for muscle movement because they connect muscles to bones. When a muscle contracts (shortens), the tendon pulls on the bone it is attached to, causing the bone to move. This action allows for coordinated movements at joints, like bending and straightening limbs. Without tendons, muscles wouldn’t be able to effectively create movement, making them essential for everyday activities like walking, running, and lifting. Additionally, tendons help stabilise joints and keep them aligned during movement.
Question 8.
Explain how actin and myosin work together to enable muscle contraction.
Answer:
- Actin filaments are thin and located on the outer sides of muscle fibres, while myosin filaments are thicker and positioned in the centre of the muscle fibres.
- When a muscle receives a signal from the nervous system, calcium ions are released inside the muscle cells.
- Calcium binds to the actin filaments, exposing binding sites for myosin. The myosin heads then attach to these binding sites, forming a cross-bridge.
- The myosin heads pull the actin filaments inward towards the centre, causing the muscle to contract.
- After this, ATP binds to the myosin heads, allowing them to detach from actin. The myosin heads return to their original position, ready to bind again and continue the contraction cycle.
Question 9.
Match the following.
| Column 1 | Column 2 |
| 1. Skeletal Muscle | a. Found in the heart, involuntary, striated |
| 2. Smooth Muscle | b. Multinucleated, voluntary, striated |
| 3. Cardiac Muscle | c. Involuntary, non-striated, found in internal organs |
Answer:
| Column 1 | Column 2 |
| 1. Skeletal Muscle | b. Multinucleated, voluntary, striated |
| 2. Smooth Muscle | c. Involuntary, non-striated, found in internal organs |
| 3. Cardiac Muscle | a. Found in the heart, involuntary, striated |
Question 10.
Observe the figure and answer the questions.
a) Identify the muscles indicated as X and Y
b) Write any two peculiarities of the muscle indicated as Y
c) Mention any one similarity between these two muscles
Answer:
a) X-Cardiac Muscle and Y-Smooth muscle
b) Smooth muscles are non-striated, uninucleated, and found in visceral organs
c) Both cardiac and smooth muscles are involuntary muscles. i.e., movements of such muscles cannot be controlled according to our will.
Question 11.
“Exercise helps our respiratory system more healthier.” Do you agree with this statement? Substantiate your answer.
Answer:
Exercise increases our vital capacity, and the exchange of respiratory gases becomes more effective.
Question 12.
Find the word pair relation and complete.
Hind limbs : 60 bones
…………… : 26 bones
Answer:
Vertebral column
Question 13.
Types of joints and their positions are given in the box. Make suitable pairs as in the given model.
Model: Pivot joint – the point where the first vertebra joins the skull
Gliding joint, Elbow, the point where the first vertebra joins the skull, the point where bones of upper arm and shoulder joins, hinge joint, wrist, pivot joint.
Answer:
Gliding joint – Wrist, Hinge joint – Elbow
Question 14.
Redraw the diagram and label the parts according to the hints given:
a) The part which covers and protects the joints
b) Functions as a lubricant between the bones
c) The part that reduces the friction between the bones.
Answer:
Question 15.
Identify the joint indicated in the following figure:
Answer:
Ball and socket joint
Question 16.
Select the correct pairs related to axial skeleton from the following options:
- Skull : 29
- Sternum : 2
- Ribs : 24
- Vertebral column : 30
Answer:
Skull – 29, Ribs – 24.
Question 17.
Complete the following table w.r.t structure of a joint:
| A | Helps in the smooth movement of bones |
| Cartilage | B |
| C | Produced by the synovial cells of the synovial membrane. |
Answer:
A – Capsule
B – It is a covering which is seen at the tip of each bone. It reduces the friction between the bones
C – Synovial fluid.
Question 18.
Fill in the blanks:
a) …………….. is the membrane which covers each bone.
b) …………….. & …………….. are the two elements which provide hardness and strength to bones.
c) …………….. cells of the bones deposit minerals in the bones which makes them strong and firm.
Answer:
a) Periosteum
b) Calcium and phosphate
c) Osteoblast cells
Question 19.
Prepare any three major concepts to be included in an awareness program on the importance of exercise based on the given hints.
Hints:
- Heart
- Lungs
- Muscles
Answer:
| Heart |
|
| Lungs |
|
| Muscles |
|
Question 20.
Explain the differences between eoskeletons and endoskelelons In terms of structure and function.
Answer:
| Endoskeleton | Exoskeleton |
| Internal framework made of bone and cartilage. | External hard covering. |
| Supports movement and protects internal organs. | Found in invertebrates (e.g., insects, crabs, mussels). |
| Grows with the organism and provides flexibility. | Protects from predators and prevents water loss. |
| Present in vertebrates like humans, birds and mammals | Offers less flexibility than an endoskeleton. |
Question 21.
Identify the word pair relationship and fill in the missing word.
a. Osteoporosis: Decreased bone density :: Rheumatoid arthritis: ………..
b. Sprain: Ligaments :: Muscular dystrophy: …………
Answer:
a. Autoimmune disorder
b. Muscles
Question 22.
What causes osteoporosis?
Answer:
Deficiency of calcium, proteins, and vitamin D causes osteoporosis.
Question 23.
Mention a function of the synovial membrane.
Answer:
The synovial membrane functions to produce synovial fluid, which lubricates the joints, reducing friction between the cartilage surfaces during movement. This fluid also provides nourishment to the cartilage and acts as a shock absorber, contributing to the overall health and function of the joints.
Question 24.
Match the following disorders with their symptoms:
| Column I | Column II |
| A. Osteoporosis | 1. Severe joint pain and swelling |
| B. Rheumatoid arthritis | 2. Weakening and degeneration of muscles |
| C. Muscular dystrophy | 3. Pain, swelling, and difficulty moving the affected joint |
| D. Sprain | 4. Back pain and frequent bone fractures |
Answer:
| Column I | Column II |
| A. Osteoporosis | 4. Back pain and frequent bone fractures |
| B. Rheumatoid arthritis | 1. Severe joint pain and swelling |
| C. Muscular dystrophy | 2. Weakening and degeneration of muscles |
| D. Sprain | 3. Pain, swelling, and difficulty moving the affected joint |
Question 25.
What are the main causes of disc prolapse, and what are its symptoms?
Answer:
Disc prolapse occurs when the gel-like part of the intervertebral disc pushes through a crack in the tougher outer layer. The main causes of disc prolapse include age-related wear and tear, where the discs naturally lose flexibility, making them prone to injury. Sudden heavy lifting, poor posture, or an accident that impacts the spine can also cause the disc to slip. Repetitive strain, such as from certain physical activities or obesity, can increase the risk as well.
Symptoms of disc prolapse include sharp pain in the lower back or neck, which may radiate down the arms or legs. This pain is often due to pressure on nearby nerves. Other common symptoms are numbness, tingling, or weakness in the affected areas. The exact symptoms depend on the location of the prolapse and which nerves are being compressed.
Question 26.
Hints related to certain disorders related to bones are given below. Analyse them and answer the questions.
| A |
|
| B |
|
a) Identify the disorders mentioned in A and B
b) What is the cause of the disorder mentioned in B.
Answer:
a) A – Rheumatoid Arthritis
B – Osteoporosis
b) Osteoporosis is caused by the deficiency of calcium, vitamin D and protein.
Question 27.
Identify the word pair relationship and fill in the missing word.
a. Exoskeleton : Crabs :: Endoskeleton : ……………
b. Bipedal Walking : Human :: Hydroskeleton : …………..
Answer:
a. Birds
b. Earthworm
Question 28.
What is Paleogenomics, and why is it important?
Answer:
Paleogenomics is the study of ancient DNA from extinct organisms or early human ancestors to understand their genetics. Scientists extract and analyse DNA from fossils or preserved remains to learn about species that lived millions of years ago. It helps in:
- Trace evolutionary history
- Understand extinct species
- Study human ancestry
Question 29.
Match the following
| Column I | Column II |
| A. Endoskeleton | 1. Study of fossils to understand the history of life |
| B. Hydroskeleton | 2. Provides internal support and flexibility |
| C. Exoskeleton | 3. Provides external protection and support |
| D. Palaeontology | 4. Movement system found in soft-bodied organisms |
Answer:
| Column I | Column II |
| A. Endoskeleton | 2. Provides internal support and flexibility |
| B. Hydroskeleton | 4. Movement system found in soft-bodied organisms |
| C. Exoskeleton | 3. Provides external protection and support |
| D. Palaeontology | 1. Study of fossils to understand the history of life |
Question 30.
Why is chemotropism essential for the reproduction of flowering plants?
Answer:
Chemotropism helps in the guidance of male gametes in the pollen tube towards the female gametes present inside the ovary of female flowers after germination.
Question 31.
Identify the word pair relationship and fill in the missing word.
a. Hydrotropism: Water :: Geotropism: ……….
b. Light: Phototropism :: Chemical: ………..
Answer:
a. Gravity
b. Chemotropism
Question 32.
Match the following
| Column I | Column II |
| A. Phototropism | 1. Non-directional response to a stimulus |
| B. Hydrotropism | 2. Growth in response to light |
| C. Chemotropism | 3. Movement towards or away from water |
| D. Nastic Movement | 4. Movement towards or away from chemicals |
Answer:
| Column I | Column II |
| A. Phototropism | 2. Growth in response to light |
| B. Hydrotropism | 3. Movement towards or away from water |
| C. Chemotropism | 4. Movement towards or away from chemicals |
| D. Nastic Movement | 1. Non-directional response to a stimulus |
Question 33.
What is haptotropism, and where can it be observed in plants?
Answer:
Haptotropism is a type of directional growth movement in plants in response to touch or physical contact with a solid object. This movement allows plants to climb or wrap around structures for support. It is possible in climbers such as peas or grapevines. When their tendrils come into contact with a support, they coil around it, helping the plant grow upward and gain better access to sunlight. This response ensures stability and enhances survival in competitive environments.
Question 34.
Complete the following illustration based on the given hints.
Hints:
Answer:
(i) Touch
(ii) Chemical substance
(iii)Haptotropism
(iv) Chemotropism
Question 35.
Analyse the situations given below and answer the questions.
(i) The leaves of touch-me-not plant fold when touched.
(ii) Climbers grow around a support
a) Identify the type of movement in situations (i) and (ii)
b) How do these movements differ from each other?
Answer:
a) (i) Nastic movements
(ii) Haptotropism
b) Nastic movements exhibited by touch-me-not plants are non-directional and not related to growth, while Haptotropism is a kind of tropic movement shown by climbers as directional and growth-related movements.