Exercise 1

Question 21 :

Primary phloem develops from

A). lateral meristem
B). protoderm
C). extrastelar cambium
D). provascular tissue
Answer : Option D

Question 22 :

Other than spreading malaria, anopheles mosquitoes are also vectors of

A). dengue fever
B). filariasis
C). encephalitis
D). yellow fever
Answer : Option B

Question 23 :

Plants that grow in saline water are called

A). halophytes
B). hydrophytes
C). mesophytes
D). thallophytes
Answer : Option A

Question 24 :

Pyorrhoea is a disease of the

A). nose
B). gums
C). heart
D). lungs
Answer : Option B

Explanation :

Pyorrhoea, or periodontal disease, to give it a proper medical term, is a disease of the gums, it is one of the most widely prevalent diseases. It affects the membrane surrounding the roots of the teeth and leads to loosening of the teeth, pus formation, and shrinkage of the gum. This disease is the primary cause for tooth loss among adults.

Question 25 :

O2 released in the process of photosynthesis comes from

A). CO2
B). water
C). sugar
D). pyruvic acid
Answer : Option B