Which of the following is true in blood transfusion?

• A. person of blood group AB can donate blood only to another person of blood group AB
• B. persons of blood groups A and B can donate or receive blood from each other
• C. A person of blood group AB acn receive blood only from persons of blood group A or B
• D. A person of blood group O can donate only to a person of blood group O

Which of the following is an effector organ?

• A. Tongue
• B. Skin
• C. Nose bridge
• D. Ear glands

Which of the following statements about chromosomes is correct?

• A. All the chromosomes of a species are the same in shape
• B. the bear number present in a species is constant
• C. they are neatly arranged in the cytoplasm
• D. They bear ribosomes on their outer membranes

Which of the following processes is not an example of a reflex ac ion?

• A. Blinking of the eye
• B. Reading
• C. Beating of the heart
• D. Sneezing

In the whistling pine, leaves are reduced to brown scales and young stems are green. This is an adaptation for

• A) obtaining food
• B) conserving nutrients
• C) storing water
• D) reducing transpiration

Carbon is added to the atmosphere by the following processes except

• A. respiration
• B. burning
• C. photosynthesis
• D. volcanic eruption

An organism X lives entirely on the waste product in another organism Y. In this association, X is a

• A) symbiont
• B) saprophyte
• C) commensal
• D) parasite

The process of maintaining a steady internal environment is known as__________

• A. osmoregulation
• B. equilibration
• C. homeostasis
• D. plasmolysis

Which of the following organisms is a chemo-autotroph?

• A. Virus
• B. Bacteria
• C. Paramecium
• D. Euglena

The addition of lime to clayed soil serves to

• A. aid water retention
• B. close up the texture
• C. prevent water logging
• D. improve capillary action