أسئلة الكتاب المدرسى على الوحدة الأولى Biology ثانوية عامة

Biology | أسئلة الكتاب المدرسى على الوحدة الأولى
Q1: Choose me correct answer:

1- The movement in man takes place by coordination of a group of systems which are….
a) The muscular, the skeletal and the circulatory systems.
b) The respiratory, the nervous and the skeletal systems.
c) The skeletal, the nervous and the muscular systems.
d) The skeletal, the respiratory and the circulatory systems.

2. The proper energy store for the muscle is:
a) ATP molecules.
b) Glycogen.
c) Glucose.
d) Lactic acid.

3. Muscle spasm during fatigue is due to accumulation of a chemical substance called:…
a) Carbon dioxide.
b) Alcohol.
c) Lactic acid.
d) Amino acid.

4. Physiological support in plants is represented by……….
a) Thickness of plant cell to prevent water loss in plants.
b) Turgidity of plant cell.
c) Turgidity of vessels filled with nutrients.
d) Deposition of cellulose on cell walls.


Q2: Give reason.

1- Tendrils twin around the support.
Ans. due to the accumulation of auxins at the side away from the support it grows faster than the side near to the support, so the tendrils twins.

2- Presence of girdles in the appendicular skeleton of animals.
To facilitate the movement and using the limbs by the action of the wide joints

3- Muscle fatigue.
* The muscle fatigue due to the inability of the blood to supply the muscle rapidly with the oxygen needed for respiration and energy production.
* Accordingly the muscle converts glycogen to glucose which oxidized anaerobically (shortage of oxygen) to produce rapid energy (2ATP) to allow the muscle to contract, causing the accumulation of lactic acid.
* Lactic acid causes muscle fatigue and stop moving to give the chance for the muscle to be supplied by enough amount of oxygen to perform aerobic cellular respiration.

4- Blood is in continuons movement inside the blood vessel.
The blood moves in arteries because of their pulsating and move in veins with the help of valves to carry out many functions as:
1- It transports digested food, O2, CO2, Nitrogenous wastes, hormones & some enzymes.
2- It regulates metabolic activities.
3- It regulates the body temperature.
4- It regulates the internal environment of the body, such as osmotic potential, quantity of water inside the tissues & the PH value of the tissue fluids.
5- It protects the body against microbes & pathogen by means of the lymphatic system.
6- It protects itself against bleeding by the formation of the blood clot.

5- The sliding theory of muscle contraction is the most acceptable to explain muscle contraction.
Because it depends on the microscopic structure of the muscle fibre as the presence of myofibrils which consists of thin actin filaments and thick myosin filaments and the sliding of the protein filaments over each other due to the presence of transverse links extended from the myosin filaments and attach to the actin filaments.

6- Presence of the enzyme cholinesterase at the neuromuscular junction.
To destroys acetylcholine into choline and acetate (acetic acid) to allow the membrane returns to its normal state “repolarization” to be ready to be stimulated and respond again.


Biology | أسئلة الكتاب المدرسى على الوحدة الأولى

Q3: Draw a labelled diagram of vertebra.
Ans:


Q4: What do you know about:
Coccigeal region - pelvic girdle - pectoral girdle - scapula - muscle bundle.
Ans:
Coccigeal region


Pelvic girdle
* The pelvic girdle consists of two identical halves fused at the ventral side at a region called the pubic sumphysis.
* Each half consists of ilium , ischium , and pubis.
* The ilium is a dorsal bone connected anteriorly to a bone called pubis at the ventral side and connected posteriorly to a bone called ischium at the ventral side.
* At the connection between ilium and ischium bones there is a deep depression called acetabulum at which the head of femur (thigh) fits forming an articulation joints.

Pectoral girdle
* The pectoral girdle (Shoulders) consists of two identical halves.
* Each half consists of scapula and clavicle bone.
* Scapula is a triangular bone, its inner end is broad, the outer end is pointed, and has a process attached to a thin bone called clavicle.
* At the scapula outer end there is a cavity called glenoid cavity through which the fore limb is jointed to form the shoulder joint

Scapula
* Scapula is a triangular bone, its inner end is broad, the outer end is pointed, and has a process attached to a thin bone called clavicle.
* At the scapula outer end there is a cavity called glenoid cavity through which the fore limb is jointed to form the shoulder joint

Muscle bundle
* Muscle bundle is a group of muscle fibres are collected together & surrounded by a membrane called perimycium.
* Each muscle fibre consists of from 1000 to 2000 myofibrils.
* Each muscle fibre (cell) consists of: cytoplasm (sarcoplasm), cell membrane (sarcolenima) , Each muscle fibre consists of:
1- Alternation of dark bands (discs) and light bands
2- The light band is called I -band and bisected by a dark line called Z- zone and formed of a thin protein filaments called actin.
3- The dark band is called A-band and bisected by a light area called H-zone and formed of another thick protein filaments called myosin.
4- The distance between each successive two Z-lines is called sarcomere.


Q5: The motor unit is the junctional unit of skeletal muscle. Discuss with reference to its components.
Ans:
The neuromuscular junction
It is the point of connection between terminal branch of the nerve fibre and the motor end plate of the muscle fibre.
* The motor unit is the unit of function of the skeletal muscles
* Each motor unit consists of a group of muscle fibres - and the nerve fibre supplying them.
* When the nerve fibre enters the muscle, it divides into a large number of branches, which supply a group of muscle fibres (from 5 to 100).

Q6: The movement is a result of coordination of the skeletal, the muscular and the nervous system in man. Explain.
a) The skeletal (bony) system:
It is suitable sites, which connect the muscles, and support the moving limbs therefore the joints play an important role in the movement.
b) The nervous system:
It gives the orders (nerve impulse) for muscles to contract and relax.
c) The muscular system:
* It is responsible for movement.
* Most of the body muscles are under the control of will ,so they are called voluntary muscles (skeletal, striated muscles).
* The other muscles are not under the control of will, so they are called involuntary muscles.