CBSE 11TH BIOLOGY - Online Test
Q1. The axillary buds of stems may also get modified into woody, straight and pointed thorns in
Answer : Option C
Explaination / Solution:
The axillary buds of stems may also get modified into woody, straight and pointed thorns in Citrus and Bougainvillea. They protect plants from browsing animals.
Q2. In animal cells, the mitotic division is seen in
Answer : Option B
Explaination / Solution:
In animals, mitotic cell division is only seen in the diploid somatic cell since mitosis produces cells with same number of chromosomes as that of parents.
Q3. The part of a nephron which adds some material to the filtrate is :
Answer : Option C
Explaination / Solution:
Each nephron consists Bowman’s cup, tubules and loops of Henle’s. filtration of blood occurs in glomerulus cells present in Bowman’s cup. Some materials are added to initial filtrate in distal convoluted tubule.
Q4. Which one is not a xylem cell?
Answer : Option C
Explaination / Solution:
Xylem is a complex tissue, which consists of four kinds of cells. These cells are tracheid, vessels, xylem parenchyma and xylem fibers. Companion cell is part of phloem tissue.
Q5. All changes that an organism goes through during its life cycle is called as
Answer : Option B
Explaination / Solution:
Development is a term that includes all changes that an organism goes through during its life cycle from germination of the seed to senescence.
Q6. Which one is exclusive characteristic of living organism?
Answer : Option B
Explaination / Solution:
The most obvious and technically complicated feature of all living organisms is this ability to sense their surroundings or environment and respond to these environmental stimuli which could be physical, chemical or biological. We sense our environment through our sense organs. Plants respond to external factors like light, water, temperature, other organisms, pollutants, etc. All organisms, from the prokaryotes to the most complex eukaryotes can sense and respond to environmental cues. Hence, the correct option is Perception of events happening in the environment and their memory.
Q7. Myoglobin is found to be :
i. highly abundant in muscles of whales and seals .
ii. exhibiting cooperative binding of oxygen.
iii. allowing organisms to hold their breathe longer underwater.
i. highly abundant in muscles of whales and seals .
ii. exhibiting cooperative binding of oxygen.
iii. allowing organisms to hold their breathe longer underwater.
Answer : Option C
Explaination / Solution:
Myoglobin is found to be highly abundant in muscles of whales and seals. Myoglobin being oxygen and iron binding protein allowing organisms to hold their breathe longer underwater.
Q8. Which one will reduce the rate of transpiration?
Answer : Option C
Explaination / Solution:
Transpiration takes place through stomata. Decrease in light intensity closes the stomata that ultimately results into reduction in rate of transpiration.
Q9. Intercalated discs occur in
Answer : Option B
Explaination / Solution:
In between cardiac muscle fibres, there are communication junctions which are made up of intercalated discs.
Q10. Which of the following organisms were placed together under algae?
Answer : Option B
Explaination / Solution:
The character of possessing cell wall in their cells grouped together the unicellular organisms and the multicellular ones, for example, Chlamydomonas and Spirogyra were placed together under algae.
