Biology - Online Test
Q1. Which one of the following is a bridge linking childhood and adulthood?
Answer : Option A
Explaination / Solution:
Adolescence is a bridge linking childhood and adulthood. It is accompanied by several biological and behavioral changes. Thus, it is a very vulnerable phase of mental and psychological development.
Q2. The choroid layer in human eye :
i. darkens the cavity of eyeball to prevent internal reflection of light.
ii. its blood vessels nourish the retina.
iii. it regulates shape of eye lens.
i. darkens the cavity of eyeball to prevent internal reflection of light.
ii. its blood vessels nourish the retina.
iii. it regulates shape of eye lens.
Answer : Option A
Explaination / Solution:
The choroid layer in human eye darkens the cavity of eyeball to prevent internal reflection of light. The blood vessels of choroid layer nourish the retina. The shape of eye lens is changed by ciliary muscles.
Q3. The megasporangium of naked seed plants are called
Answer : Option B
Explaination / Solution:
The cones bearing megasporophylls with ovules or megasporangia are called macrosporangiate or female strobili.
Q4. The process of movement of few ions or molecules across the membrane against concentration gradient from higher to lower concentration, it is called
Answer : Option A
Explaination / Solution:
The solutes may move across the membrane by the process of simple diffusion along the concentration gradient, i.e., from higher concentration to the lower.
Q5. Why are UGA, UAG and UAA called termination codons?
Answer : Option D
Explaination / Solution:
The three codons, UAA known as ochre, UAG as amber and UGA as opal, that do not code for an amino acid but act as signals for the termination of protein synthesis. So they also Known bas termination codon.
They are not represented by any tRNA and termination is catalysed by protein release factors.
Q6. The first product of photosynthesis is sugar and it is converted
Answer : Option A
Explaination / Solution:
Photosynthesis is the process by which plants, some bacteria and some protistans use the energy from sunlight to produce glucose from carbon dioxide and water. The glucose is used in respiration, or converted into starch and stored.
Q7.
Name the unlabelled parts of given flow chart :
Answer : Option B
Explaination / Solution:
The flow chart of respiratory mechanism labeled as stretch, expiratory centre and inspiratory centre respiratory. It is controlled by the medulla and pons of hind brain.
Q8. The management of animal for milk and its product for human consumption is called
Answer : Option A
Explaination / Solution:
Dairying or dairy management is the process and system that increase yield and increase the quality of milk. Milk yield is primarily dependent of quality of breeds in the farms.
Q9. Humans have increased extinction rate by a factor of
Answer : Option D
Explaination / Solution:
Various human activities like pollution, deforestation, urbanization, industrialization have increased the extinction rate of various organisms by a factor of 1000.
Q10. Read the following statements :
i. endocrine system corrects the imbalance originally detected by the nervous system.
ii. nerve cells and endocrine cells exist side by side in adrenal gland and pituitary.
i. endocrine system corrects the imbalance originally detected by the nervous system.
ii. nerve cells and endocrine cells exist side by side in adrenal gland and pituitary.
Answer : Option A
Explaination / Solution:
Endocrine system corrects the imbalance originally detected by the nervous system. Nerve cells and endocrine cells exist side by side in adrenal gland and pituitary gland.
