Download App

Human Health and Disease — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYHuman Health and Disease1 Mark
MCQ
For question, two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion :Mucous membrane immobilises the micro$-$organisms in the body
Reason: Microorganisms and dust particles entering the respiratory tract are trapped in the mucus.
  • ✓
    Both assertion and reason are true, and reason is the correct explanation of assertion.
  • B
    Both assertion and reason are true, but reason is not the correct explanation of assertion.
  • C
    Assertion is true, but reason is false.
  • D
    Both assertion and reason are false.
✓

Answer

Correct option: A.
Both assertion and reason are true, and reason is the correct explanation of assertion.
Innate immunity is non$-$specific type of defence, that is accomplished by providing different types of barriers to the entry of the foreign agents into our body. Mucus coating of the epithelium lining in the respiratory, gastrointestinal and urogenital tracts traps microbes and prevents their entry in our body.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Assertion (A) & Reason (B) MCQ" from Human Health and Disease→Human Health and Disease — all question types→BIOLOGY STD 12 Science question papers→Maharashtra Board STD 12 Science question papers→Maharashtra Board question paper generator→

Similar questions

Two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Azolla is used as a biofertiliser in rice fields.
Reason: Azolla shows the presence of $N_2 -$ fixing bacteria in its leaf cavities.
→
For question two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Mimicry is the resemblance of one organism to another.
Reason: Mimicry may be protective or aggressive.
→
Two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Rhizobium forms nodules on the roots of legume plants.
Reason: Rhizobium fixes atmospheric nitrogen into organic forms which is used by the plant as nutrients.
→
For question two statements are given $-$ one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion : Many endemic species are seen to flourish in sacred forests.
Reason : Sacred forests are undisturbed forest patches and biodiversity rich areas.
→
Two statements are given $-$ one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion : Soil inhabiting bacterium Agrobacterium tumefaciens is called a natural plant genetic engineer.
Reason : Agrobacterium tumefaciens produce crown galls in several dicot plants.
→
Some multinational companies patent biological sample of other country without permission is called as :
→
For question two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Hybrids are generally superior than their parents.
Reason: All the dominant traits are present in the hybrid.
→
Read the following and answer any four questions from $(i)$ to $(v)$ given below:
In angiosperms, the pollen grains are being transferred from the anther to the stigma and is termed pollination. This phenomenon was first discovered by Camerarius $(1694)$ in the end of seventeenth century. Pollen grains are immobile. They cannot reach the stigma by themselves. An external agent is required for this. The pollination is mainly of two types$-$self pollination and cross pollination. The diagram given below shows two plants of the same species showing different types of pollination.
  1. What is transferred between the plants in the process indicated by arrow $P?$
  1. Ova.
  2. Pollen.
  3. Nutrients.
  4. Seeds.
  1. Which of the following statements is correct regarding processes $P, Q$ and $R?$
  1. Processes $P, Q$ and $R$ introduce genetic variability in the offspring of sexually reproducing plants $X$ and $Y.$
  2. Wind serves as agent for process $Q$ if plants $X$ and $Y$ belong to Genus Salvia.
  3. Flowers of plants $X$ and $Y$ need to produce odour and nectar for completion of processes $P$ and $Q$ if they are entomophilous.
  4. If plants $X$ and $Y$ belong to Genus Cannabis, then their flowers need to produce sticky and heavy pollens in very small amount for accomplishment of process $Q.$
  1. Identify the processes $P, Q$ and $R.$
S. No $P$ $Q$ $R$
$(a)$
Geitonogamy
Xenogamy
Autogamy
$(b)$
Allogamy
Chasmogamy
Cleistogamy
$(c)$
Autogamy
Geitonogamy
Xenogamy
$(d)$
Geitonogamy
Allogamy
Autogamy
  1. In Catliarantl1us, the growth of style brings the stigma in contact of ripe anthers present on the mouth of corolla tube. This is an example of:
  1. Homogamy.
  2. Cleistogamy.
  3. Geitonogamy.
  4. Xenogamy.
  1. Which of the given processes represents a type of pollination that would result in greater adaptability of the particular species to potential environmental changes?
  1. $P.$
  2. $Q.$
  3. $R.$
  4. All of these.
→
For question, two statements are given-one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes$ (a), (b), (c)$ and $(d)$ as given below.
Assertion : Brown sugar is morphine-derivative
Reason: Morphine is the principal opium alkaloid.
→
For two statements are given$-$one labelled Assertion and the other labelled Reason. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion: Cross pollination is the only means of pollination in unisexual flowers.
Reason: Self$-$sterility is the only way to prevent self$-$pollination in bisexual flowers.
→