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.

Red striated muscle fibres. Their abundant myoglobin and mitochondria enable them to serve their purpose.

Trachea, fallopian tube and bronchiole.

The centre of the A band, not overlapped by the thin filaments, is called H zone.

Ball and socket joint.

It is the flat expended process of scapula.

A- 80 bones, B- Skull, C- Vertebral column and D- Sternum .

1. Cilia help in the movement of food through the cytopharynx.
2. They also help in locomotion of the cell.

Olecranon process on top of the ulna is called the funny bone.

Contractile property of muscles.

1. The globular head.
2. Myoglobin.

Cartilaginous joint is present in between the vertebrae. It allows slight movement because of the elastic pads of fibrocartilage present between the ends of bones taking part in the joints.

Myoglobin or muscle haemoglobin.

Old people generally develop osteoarthritis because the secretion of synovial fluid in the joints decreases with age.

1. The bones found in middle ear are called ear ossicles (malleus, incus and stapes).
2. Mammals in general has seven cervical vertebrae in neck Inte region.

Myoglobin.

Two parts of human endoskeleton are as follows:

1. Axial skeleton, it comprises of 80 bones.
2. Appendicular skeleton, it comprises of 126 bones.

Still's disease is a kind of rheumatoid arthritis that occurs in younger people.

Skcletal Murcle	Smooth Muscle	Cardlac Mutclc
Striated appearance	Non-striated appearance	Striated appearance
Unbranched	Unbranched	Branched
Voluntary	Involuntary	lnvoluntary
Present in skeletal system	Present in internal organs	Present in heart

1. It is located at the base of the buccal cavity.
2. It is 'U' shaped.

Skeletal muscles have stripes on them, hence they are also known as striated muscles.

1. Food capture.
2. Locomotion.

Fibrocartilage.

1. Meromyosin.
2. 'G' (globular) actins.

They are involuntary in function.

Ilium, ischium and pubis form the coxal bone.

Human body contains 206 bones. Femur is the largest and strongest bone of human body.

Two important parts of meromyosin are:

1. Globular head with short arm, called Heavy Meromyosin (HMM).
2. Tail, called the Light Meromyosin (LMM).

Girdle bones help in the articulation of limb bones with the axial skeleton.

Macrophages and leucocytes.

Malleus, incus, stapes.

1. Excitability.
2. Contractility.
3. Extensibility.
4. Elasticity.

Sarcomere.

Actin and myosin filaments are responsible for muscle contraction.

Acetabulum.

When acetylcholine is released from nerve cells the calcium channels open in muscles. This facilitates sliding of actin filaments towards each other. This results in muscle contraction.

Tetany refers to the rapid spasms (wild contractions) of the muscles, caused by low levels of calcium in body fluids.

1. Muscular dystrophy.
2. Myasthenia gravis.

Myosin.

F actin, troponin and tropomyosin.

The protein chondroitin is responsible.

1. Fascia.
2. Sarcoplasmic reticulum.

The joint between the adjacent vertebrae of vertebral column.

Muscles require ATP to relax as well as to contract. On animal's death, its muscles soon exhaust ATP and lose the ability to contract or relax. They become rigidly locked in whatever position they were when ATP gets completely used up. This phenomenon is known as mo Rigor Mortis. It is used in determining the time of death.

The 11th and 12th ribs are called floating ribs. These are two in numbers.

1. Atlas.
2. Axis.

It reduces friction between the articulating bones.

Sarcoplasmic reticulum.

High concentration of chondroitin salts.

All mammals have 7 cervical vertebrae.