Biology Today - February 2018

Abiotic Factors Temperature It is the degree of hotness or coldness of a substance. It ranges from subzero levels in polar ar ...

Thermoperiodicity Regular change in body temperature that occurs at specific time interval. Diurnal thermoperiodicity Temperatur ...

Light Zones in Aquatic Habitats Zones in lake water are determined by gradients of light, oxygen and temperature from the water ...

O-horizon Surface layer of organic matter, rich in humus. A-horizon Uppermost horizon of soil, called top soil. Rich in organ ...

Man is always most important biotic factor. He changes the environment by his activities regularly, HJ, by excessive cutting ...

(vii) Behavioural adaptations Keep their body temperature fairly constant by behavioural means. They enjoy in the sun and absorb ...

If N is the population density of time t, then its density at time t + 1 is: Nt + 1 = Nt + [(B + I) – (D + E)] Exponential gro ...

Competition It is a rivalry between two or more organisms for obtaining the same resources. It can be intraspecific (among in ...

Another well known example of mutualism is furnished by the bacteria of the genus 5KL]RELXP. These bacteria form nodules on the ...

Resemblance of Monarch butterfly and Queen butterfly is an example of (a) camouflage (b) warning colouration (c) Mullerian mimi ...

Which of the given statements are incorrect for exponential growth model? (i) It has four phases - lag, log, deceleration and s ...

CHAPTER-8 : HUMAN HEALTH AND DISEASES Multiple Choice Questions The causal organism of yellow fever is (a) Paramyxovirus (b) Ru ...

In an antibody, (a) heavy chains have more number of amino acids than light chains (b) heavy chains have less number of amino a ...

Carefully observe the given figure and answer the following questions. N O CH 3 CH 3 O H O H O (a) Identify the compound havin ...

Match Column I with Column II (There can be more than one match for items in Column I). Column I Column II A. Malvi (i) Bacteri ...

CHAPTER-10 : MICROBES IN HUMAN WELFARE Multiple Choice Questions Which is incorrect among the given statements? (a) Hard cheese ...

whereas pilot plant scale uses metallic container called (iv). Microorganisms are added in (iv) in three ways : (a) (v) growth s ...

SOLUTIONS CHAPTER-8 : HUMAN HEALTH AND DISEASES (c) 2. (c) 3. (c) 4. (c) 5. (d) (c) 7. (c) 8. (b) 9. (a) 10. (d) A-(iv), B-(v), ...

SECTION - A What is the role of filiform apparatus in embryo sac? Arrange the following primates in increasing order of brain c ...

Refer to the given diagram of (FROL cloning vector pBR322. Answer the following questions: (a) Indicate the antibiotic resist ...