Biology - Online Test
Q1. In mosses, the sex organs are arise from
Answer : Option B
Explaination / Solution:
In sexual reproduction, the sex organs antheridia and archegonia are produced at the apex of the leafy shoots.
Q2. Who was the first to explain that cells divide?
Answer : Option C
Explaination / Solution:
The German doctor Rudolf Virchow proposed in 1855 that all cells result from the division of previously existing cells, and this idea became a key piece of modern cell theory.
Q3. RNA molecules that act as enzymes are called
Answer : Option C
Explaination / Solution:
Until about 20 years ago, all known enzymes were proteins. But then it was discovered that some RNA molecules can act as enzymes; that is, catalyze covalent changes in the structure of substrates (most of which are also RNA molecules). Catalytic RNA molecules are called ribozymes.
Only a few RNA molecules act as enzymes.
Q4. plants respond to higher concentration leads to
Answer : Option A
Explaination / Solution:
The fact that plants respond to higher concentration byshowing increased rates of photosynthesis leading to higher productivity .They are allowed to grow in carbon dioxide enriched atmosphere that leads to higher yields.
Q5. Insect of family chironomidae eg..chironomous larvae are also known as bloodworms since :
Answer : Option A
Explaination / Solution:
Insects of family Chironomidae eg. Chironomous commonly known as the harlequin fly, is a species of non-biting midge. Their larvae are known by the common name of blood worm due to their red colouration. Red colouration is because they contain haemoglobin as their respiratory pigment.
Q6. Which one of the following pair is incorrectly matched in respect to the "crop varieties for disease resistance"?
Answer : Option D
Explaination / Solution:
Wheat plants are generally not infected by leaf and stripe rust. Common disease of wheat includes rust and smut disease. Wheat plants are not develop resistance for leaf and stripe rust.
Q7.
Read the following statements:
i) Insects are essentially absent from the sea.
ii) The species diversity on land is generally considerably lower than oceans.
Answer : Option C
Explaination / Solution:
Insects are essentially absent from the sea because insects respire using trachea from air.The species diversity on land is generally considerably higher than ocean therefore, statement ii is incorrect.
Q8.
Match the following :
| Disease | Hormone source responsible |
| a) Cushion syndrome | i) hyposecretions from pars nervosa |
| b) Diabetes mellitus | ii) hyposecretion of mineralocorticoids |
| c) Diabetes insipidus | iii) hyposecretion of glucocorticoids |
| d) Addison’s disease | iv) hyposecretion from beta cells of pancreas |
Answer : Option A
Explaination / Solution:
Cushing’s syndrome occurs hypo-secretion of glucocorticoids hormone. Diabetes mellitus is due to hypo-secretion of beta cells of pancreas. Diabetes insipidus is due to hypo-secretion form pars nervosa and Addison’s disease is due to hypo-secretion of mineral corticoids.
Q9. Which one of the following do not belonging to Urochordata?
Answer : Option B
Explaination / Solution:
Lancelets are classified in the phylum Chordata , subphylum Cephalochordata. lancelet, name for small, fishlike lower chordate also called amphioxus it shows many affinities with the vertebrates. There are about 30 lancelet species, most belonging to the genus Brachiostoma (formerly Amphioxus ). Lancelets are usually about 1 in. (2.5 cm) long, with transparent bodies tapered at both ends. There is no distinct head and no paired fins.
Q10. The number of polar bodies formed during oogenesis in human being is
Answer : Option A
Explaination / Solution:
During oogenesis reduction division occurs in primary oocytes to produce one polar body and secondary oocytes. Polar bodies further divide to form two polar bodies. Secondary oocytes further divide to produce one polar bodies and a secondary follicle to produce ovum.
