Science [1 Mark Questions]

Endocrinal and nervous tissues are two tissues which provide control and coordination to multi cellular animal.

The largest cell in human body is a female OVUM (egg).Taking about the size of the ovum it is roughly a millimeter across and just visible to naked eyes.

Phytohormones.

As the electrical impulse reaches the axon terminal in the region of axon-dendrite synapse, it stimulates the exocytosis of vesicles containing neurotransmitter (e.g. acetylcholine). Neurotransmitter attaches to the chemoreceptor sites of the membrane covering the dendrite end of synapse. It creates a new impulse that travels through cell body and axon of the second neuron. At synapse, the axon end does not contain any chemoreceptor sites so that reverse flow of electrochemical impulses is not possible.

Dwarfism. Growth hormone.

Goitre.

No, a reflex action is not the only function of the spinal cord. it is function of The central nervous system which consists of spinal cord and brain.

Growth hormone.

Cranium is a bony box in the skull in which the brain is present. Its function is to protect the brain.

Cerebellum.

Central nervous system and Peripheral nervous system.

Receptors (Olfactory).

Abscisic Acid.

Abscisic acid.

The hypothalamus also maintains homeostasis in lots of other ways, such as by controlling your blood pressure. The temperature in your body, like the temperature in your home, is a balance between different cooling and heating systems. The hypothalamus also controls many of your hormones.

The three types of nerves which make up the peripheral nervous system are: spinal nerves, cranial nerves and visceral nerves.

Goitre: The neck of the person appears to be swollen due to the enlargement of thyroid gland located in the neck.

Cytokinin.

Root bends downwards in the direction of gravity; positive geotropism.

Cerebellum.

Auxin.

Auxin.

1. Dendrite.
2. Cell body.
3. Axon.
4. Nerve ending.

Iodine.

Diabetes.

Figure (a) is more accurate as it shows appropriate response of both shoot and root to the vector of gravity. Shoot is negatively geotropic. It, therefore, bends upwardly. Root is positively geotropic. It, therefore, bends downwardly.

Abscisic acid is responsible for the wilting and falling of leaves in plants.

Gland with Digestive Enzymes and Hormones. Pancreas.

The structural and functional unit of nervous system is neuron.

Part of the brain Hind BrainIt plays a role in controlling the heart rate, breathing, blood pressure, sleep and waking up functions etc. The hindbrain has three parts, namely–medulla oblongata, pons and cerebellum.

Diet provides iodine for making thyroxine hormone which keeps the thyroid gland healthy.

A voluntary action is basically an action which initiates by our own conscious. The brain sends impulses from it to the effectors (muscles or glands) via the spinal cord with neurons and finally a motor neurons. This action is under the control of the will thus is known as a voluntary action.
For example: Breathing.

Retina.

1. In both the cases the movement caused by touch is same.
2. In the case of sensitive plant movement takes place away from the point of contact and in the case of peas plant the movement takes place at the point of contact.
3. In mimosa plant, this movement is seen because of the change in concentration of water in the leaves.
4. In pea plant, this movement is seen because of the rapid growth of that part of a tendril which is away from the stimulus or the support.

Growth.

Auxin.

Sperm production, development of secondary sexual characters during puberty.

Thyroid gland.

Endocrine glands.

1. Root.
2. Stem.

Testosterone.

The spinal cord (and brain) are protected by three layers of tissue or membranes called meninges, that surround the canal. The dura mater is the outermost layer, and it forms a tough protective coating. Between the dura mater and the surrounding bone of the vertebrae is a space called the epidural space.

Endocrine Gland in Males only Testis.

Thigmonasty.

Controls general metabolism and growth in the body.

The part of a fore-brain Occipital lobe Is responsible for visual processing Is.

1. Knee jerk reflex.
2. Sneezing.
3. Coughing.

Stem grows upward against the direction of gravity; negative geotropism.

Nervous system and endocrine system.