BIOLOGY 1 Marks Question

True.

False. H -zone of striated muscle fibre is the central part of the thick filament that is not overlapped by the thin filament.

The number of phalanges in each limb of human is 14.

All mammals (except a few) have 7 cervical vertebra.

False.There are 12 pairs of ribs in a man.

True.

Thin filament of myofibril contains 2 ‘F’ actins and two other proteins namely tropomyosin and troponin.

True.

In a muscle fibre Ca++ is stored in sarcoplasmic reticulum.

11th and 12th pairs of ribs are called floating ribs.

The human cranium is made of 8 bones.

Synovial fluid.

The terms are referred to muscle fibre Sarcolemma– Plasma membrane Sarcoplasm– Cytoplasm Sarcoplasmic reticulum– Endoplasmic reticulum.

1. Mesoderm.
2. Myofilaments/ Myofibrils.

Malleus, incus and stapes. These are found in internal ear.

Skull is also known as brain box. The main role of skull is to give protection to brain. Apart from this the human skull is positioned in a way which makes it easy for humans to stand erect. This type of position is called Frankfurt plane.

Since the white muscle fibres have no/ little oxygen storage, they are anaerobic and get fatigued fast.

Accumulation of lactic acid.

Because of the presence of two occipital condyles.

High concentration of calcium salts.

It is located on the dorsal part of the thorax between the second and the seventh ribs.

Extensor muscle of human back.

1. Ciliary movement in trachea helps remove dust particles.
2. Passage of eggs in fallopian tubes is facilitated by ciliary movement.

When access of uric acid crystals get accumulated in the joints like ankle, knee, etc., they cause pain. This is called gout arthritis.

Since these muscles have large amount of oxygen stored in myoglobin and a number of mitochondria that can use the oxygen to produce ATP, these muscles are called aerobic muscles.

It provides articulations to the bones of legs. It supports and protects abdominal visceral organs and provides attachment to certain leg muscles.

Some examples of flagellar movement are as follow:

1. Swimming of spermatozoa.
2. Maintenance of water current in the canal system of sponges.
3. Locomotion in Euglena.

Chondrion.

Special properties of muscles are: Excitability, Contractility, Elasticity, and Extensibility.

1. Glenoid cavity.
2. Acetabulum.

Ball and socket joint is present between the humerus and pectoral girdle. It is also present between the femur and pelvic girdle.

Certain muscles have low concentration of myoglobin which gives them a white appearance. They depend on anaerobic process for energy and are called as anaerobic muscles.

Chemical energy.

Sternum is a flat dagger-shaped bone located on the ventral midline of thorax. Rib bones attach themselves with sternum in the front.

The red muscle fibre have reservoir of oxygen in the form of myoglobin. The anaerobic conditions are not created soon. This avoids muscle fatigue.

Sternum.

Certain muscles have high concentration of myoglobin which gives it a red appearance. They also contain plenty of mitochondria which utilize large amounts of oxygen to produce ATP. Because of this they are also called aerobic muscles.

Intervertebral joint.

1. This condition is called arthritis.
2. Decreased levels of estrogen causes osteoporosis.

It is the junction between a motor neuron and the sarcolemma of the muscle fibre.

1. 8
2. 14

Methods of locomotion vary with animal's habitat and demand of situation.

The continuous contraction and relexation in muscles cause movement in organs. If it continues for longer time then anaerobic conditions are created in muscle cells and an aerobic respiration begins due to which lactic acid is formed. Thus, accumulation of lactic acid causes muscle fatigue. After taking some rest in some course of time liver degrades the lactic acid and person is relieved from pain.

Our fore arm is made of radius, ulna and carpals.

Muscle fibre is a syncitium as the sarcoplasm contains many nuclei. Myofilaments are parallelly arranged and are present in large number in muscle fibre.

Pectoral girdle provides fulcrum to forelimbs.

Movement of spermatozoa in the female reproductive tract.