CBSE 11TH BIOLOGY - Online Test
Q1. Tracheal tube divides into right and left bronchi at the level of :
Answer : Option A
Explaination / Solution:
Trachea divides at the level of 5th thoracic vertebra into a right and left primary bronchi.
Q2. Which phylum contain acoelomic and triploblastic animals?
Answer : Option C
Explaination / Solution:
Those animals in which the developing embryo has a three germinal layer, mesoderm in between the ectoderm and endoderm, are called triploblastic animals and absence of internal body cavity is called as acoelomic.
Q3. The number of substrate molecules changed per minute by a molecule of enzyme is called
Answer : Option C
Explaination / Solution:
The number of substrate molecules changed per minute by a molecule of enzyme is called turn over number. Higher the turn over number more effective is the enzyme.
Q4. Which of the following blood components play a major role in blood coagulation ?
Answer : Option A
Explaination / Solution:
Platelets also called thrombocytes are cell fragments produced from megakaryocytes. Platelets can release a variety of substances most of which are involved in the coagulation or clotting of blood.
Q5. Organism which depend on dead and decaying organic matter is
Answer : Option A
Explaination / Solution:
A saprophyte or saprotroph is an organism which gets its energy from dead and decaying organic matter. This may be decaying pieces of plants or animals.
This means that saprophytes are heterotrophs. They are consumers in the food chain.
Q6. Monstera has
Answer : Option B
Explaination / Solution:
In some plants, like grass,Monsteraand the banyan tree, roots arisefrom parts of the plant other than theradicle and are called adventitious roots
Q7. Plants show mitotic divisions in -------------
Answer : Option C
Explaination / Solution:
The plants can show mitotic divisions in both haploid and diploid cells due to alternation of generations in life cycle.
Q8. Blood enters glomerular capillaries through _____ arteriole and leaves through _____ arteriole:
Answer : Option A
Explaination / Solution:
The blood plasma is filtered through the capillaries of the glomerulus into the capsule. The Bowman's capsule empties the filtrate into the proximal tubule that is also part of the duct system of the nephron. A glomerulus receives its blood supply from an afferent arteriole of the renal circulation
Q9. The tissue present in all organs of plant is
Answer : Option D
Explaination / Solution:
Generally all the organs of plant are made up of parenchyma cells.
Q10. How many cells per hour does a single maize root apical meristem can give?
Answer : Option C
Explaination / Solution:
Growth is measured by a variety of parameters some of which are: increase in fresh weight, dry weight,length, area, volume and cell number.
one single maize root apical mersitem can give rise to more than17,500 new cells per hour, whereas cells in a watermelon may increase in size by upto 3,50,000 times.
In the former, growth is expressed as increase in cell number; the latter expresses growth as increase in size of the cell.
