Tag: organization of life

Questions Related to organization of life

Most vertebrates can maintain a constant internal osmolarity different from the surrounding medium, except

  1. Myxine

  2. Sharks

  3. Bony fishes

  4. Both $(A)$ & $(B)$


Correct Option: D

COHb' stands for

  1. Carbonmonoglobin

  2. Carboxyhemoglobin

  3. Carbonmonooxide

  4. Carbon dioxide


Correct Option: B

Osmoconformers are the animals that __________________.

  1. Do not actively control the osmotic condition of their body fluid

  2. Actively control the osmotic condition of their body fluid

  3. Maintain the condition of body fluid within a narrow osmotic range

  4. Do not change the body fluid according to the osmolarity medium


Correct Option: A

Match column I   with column II and select the correct option from the given codes. 
    Column I                                  Column II
A..Eurythermal                  (i) Able to tolerate narrow range of                                                        temperature
B. Stenothermal                (ii) A stage of suspended 
                                               development 
C. Conformers                   (iii) Body temperature changes with                                                    ambient  temperature
D. Diiapause                      (iv) Able to tolerate wide range of                                                      temperature

  1. A-(iv), B-(i), C-(iii), D-(ii)

  2. A-(iv), B-(i), C-(iii), D-(i)

  3. A-(ii), B-(iv), C-(iii), D-(i)

  4. A-(i), B-(i), C-(iii), D-(iv)


Correct Option: A
Explanation:
 Eurythermal organisms are able to tolerate wide range of  temperature.
Stenothermal organisms are   able to tolerate narrow range of temperature.
Body temperature of Conformers changes with ambient temperature.
A stage of suspended development is called Diapause.
So, the correct option is 'A-(iv), B-(i), C-(iii), D-(ii)'
             

Most of the homeostatic mechanisms operate through feed back mechanism. The best example is illustrated by

  1. Hormones

  2. Enzymes

  3. Vitamins

  4. Ribozymes


Correct Option: A
Explanation:

Hormones provide the best feedback mechanism. There are positive feedback mechanism in which the hormone stimulates the production of itself example estrogen before ovulation.

There also are negative feedback mechanism where a hormone inhibits its own production example thyroid hormone ( $T _4$ ).
Enzymes, vitamins and Ribozymes do not show such feedback mechanism.
So the correct option is ' Hormones'.

"Homeostasis" term was proposed by

  1. Claude Bernard

  2. Walter cannon

  3. Maroello Malopighi

  4. Henle


Correct Option: B
Explanation:

Homeostasis is the process of maintaining a constant and stable internal environment by an organism. This term was first described in 1865 by Claude Bernard and coined by Walter Bradford Cannon in 1930. The word is derived from Greek where 'home' means 'similar' and 'stasis' means 'stable'. So, the correct answer is "Walter Cannon'.

A condition is which the body's internal environment remains relatively constant within limits is

  1. Hematoma

  2. Homeostasis

  3. Haemopoiesis

  4. Hemostasis


Correct Option: B
Explanation:

Homeostasis is the tendency to resist change in order to maintain a stable, and constant internal environment. The internal environment should be contains the optimum concentration of gases, nutrients, ions, and water, has an optimal temperature, and has an optimal pressure for the health of the cells. For example, the concentration of various ions in the blood must be kept steady, along with pH and the concentration of glucose. Maintenance of homeostasis usually involves negative feedback loops. These loops act to oppose the stimulus. Its works on first, high temperature will be detected by sensors—primarily nerve cells with endings in the skin and brain—and relayed to a temperature-regulatory control center in brain. The control center will process the information and activate effectors—such as the sweat glands—whose job is to oppose the stimulus by bringing body temperature down.


Choose the correct answer from the alternatives givens.
Which of the following body systems contribute to homeostasis?

  1. Digestive and excretory systems

  2. Respiratory and nervous systems

  3. Nervous and endocrine systems

  4. Immune and cardiovascular systems


Correct Option: C
Explanation:

  • Homeostasis is the tendency towards a relatively stable equilibrium between interdependent elements maintained by the physiological process.
  • In the body, some systems support  homeostasis, like the nervous and endocrine system
So, the correct answer is 'nervous and endocrine system'

Choose the correct answer from the alternatives givens.
When a human being is cold, the superficial blood vessels

  1. dilate, and the sweat glands are inactive

  2. dilate, and the sweat glands are active

  3. constrict, and the sweat glands are inactive

  4. constrict, and the sweat glands are active


Correct Option: C
Explanation:

Vasoconstriction occurs in superficial blood vessels of warm-blood vessels of warm-blooded animals when their ambient environment is cold, this process diverts the flow of heated blood to the center of the animal, preventing the loss of heat

So, the correct answer is 'constricted, and the sweat glands are inactive'

State whether the following statements are true or false .
A self-regulated system is said to be in a state of homeostasis

  1. True

  2. False


Correct Option: A
Explanation:

Homeostasis is a self-regulating system inside living organisms that keep conditions like pH, temperature, osmolarity constant. This system is self-regulatory in the sense that keeping a stable internal environment requires constant adjustments as conditions change and these adjustments are all automatically made without conscious effort or external effort from anywhere. 

So, the correct option is 'True'.