Tag: endocrine system and chemical co-ordination

Questions Related to endocrine system and chemical co-ordination

Which of the following hormone is steroid?

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. Epinephrine

  2. Thyroxine

  3. Estrogen

  4. Gonadotropin

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Correct Option: C
Explanation:
The steroids are organic compounds involved in biological processes. Steroid hormones are generally synthesized from cholesterol in gonads and adrenal glands. They are basically lipids. For example, estrogen, progesterone, testosterone, etc.
Thus, the correct answer is 'Estrogen.'

Hormone responsible for the absorption of water in DCT is

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. ADH

  2. ACTH

  3. Oxytocin

  4. Insulin

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Correct Option: A

A paracrine hormone is 

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. a local hormone that acts on the cell that releases it.

  2. always acting on a wide variety of target tissues.

  3. a local hormone produced at one site but active at a different site in the body

  4. none of the above

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Correct Option: B

Hormones are produced at a particular centralized site and transported throughout the organism by means of 

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. a series of synapses

  2. an integrated neural pathway system.

  3. cellular communication

  4. an internal transport system

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Correct Option: C

Steroid-based hormones are able to act inside the cell. This is possible because

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. there are no receptors for hormones on the cell surface

  2. hormones must interact with the nucleus to have an effect.

  3. proteins carry them into the cell

  4. steroid-based hormones are hydrophobic molecules that can pass through the cell membrane.

Show answer
Correct Option: D
Explanation:
Steroid based hormones are fat soluble so they can enter the cell easily after which they bind to the specific steroid receptors and perform the required activities on the cell. And because they are lipids(hydrophobic molecules)  so they can enter the cell membrane.
So, the correct option is 'steroid-based hormones are hydrophobic molecules that can pass through the cell membrane'

The mode of action of steroid hormones involves

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. a second messenger.

  2. modification of enzyme activity.

  3. stimulation of DNA replication.

  4. stimulation of mRNA transcription

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Correct Option: A

All of the following statements are true about hormones except

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. They are transporated by the circulatory system

  2. They bind to receptors on target cells

  3. They must be present in large quantities to have an effect

  4. They are secreted by endocrine glands

  5. They can affect organs of the body that are far removed from their site of synthesis

Show answer
Correct Option: C
Explanation:
1. Hormones are produced by specialized glands(endocrine glands) and are secreted directly into the bloodstream.
2. Hormones are transported by the bloodstream from the endocrine cells to serve as ‘chemi­cal messenger’ which act on target cells or organs by regulating the rates of specific metabolic reactions. 
3. Hormones exert their effects not where they are locally produced, but on other tissues of the body. 
4. Hormones are required in very small amounts and their effect may be excitatory or inhibitory depending upon their concentration and the physiological state of the responding tissue. Hence, All of the following statements are true about hormones except They must be present in large quantities to have an effect. 
So, the correct answer is 'They must be present in large quantities to have an effect'.  

Choose the peptide hormone from the following

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. adrenaline

  2. Insulin

  3. Testosterone

  4. Progesterone

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Correct Option: B
Explanation:

Peptide hormones are the one which have single or multiple long amino acid chain/s. Insulin is a peptide hormone with two amino acid chains, one with 21 and other with 30 amino acids. This makes option B correct. 

Identify the incorrect pair.

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. Fatty acid- Insulin

  2. Glucose- Chitin

  3. Thymine- Nucleotide

  4. Amino acid- Hemoglobin

  5. Nitrogen- Uric acid

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Correct Option: A
Explanation:

Chitin is a polymer of N-acetyl glucosamine which in turn is a derivative of glucose. 

Thymine one of the purine (nitrogenous base) that makes deoxyribonucleotide units of DNA. 
Hemoglobin has four protein subunits, two alpha-globin and two beta-globin. Uric acid is a heterocyclic compound of CHON. 
Insulin is a protein hormone secreted by the pancreas.
So, the correct answer is option A.

Chemically hormones are

zoology endocrine system and chemical co-ordination classification of hormones endocrine system and hormone hormones and metabolism

  1. Biogenetic amines only

  2. Proteins, steroids and biogenetic amines

  3. Proteins only

  4. Steroids only

Show answer
Correct Option: B
Explanation:

Hormones are certain essential substances in our bodies that are released by our body's endocrine system.  They are chemical messengers in our bodies that transmit messages for the action of various glands in our bodies and their secretions. 

Hormones are made up of certain chemical substances like proteins,  steroids and biogenetic amines. So, option B " proteins, steroids and biogenetic amine" is the correct option.