MCQ 11 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Potato tuber is used for the vegetative reproduction of potato plant.
Reason : Potato tuber is an underground stem of the potato plant.
- A
Both $A$ and $R$ are true and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true but $R$ is not the correct explanation of the assertion.
- C
$A$ is true but $R$ is false.
- D
$A$ is false but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true but $R$ is not the correct explanation of the assertion.
Potato tuber is an underground stem of the potato plant. A potato tuber has many buds $($also called eyes$)$ on its body. These buds act as organs for vegetative reproduction. When a potato tuber is implanted in the soil, then the various buds of the potato tuber start growing to from new potato plants.
View full question & answer→MCQ 21 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Multiple fission produces many daughter cells simultaneously.
Reason : Multiple fission occurs during favourable conditions.
- A
Both $A$ and $R$ are true and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true but $R$ is false.
- D
$A$ is false but $R$ is true.
AnswerCorrect option: C. $A$ is true but $R$ is false.
In multiple fission, the parent organism divides into many daughter cells at the same time during unfavourable conditions like deficiency of food or water and extremes of temperature. Production of large number of daughters increases the chances of survival of daughter cells.
View full question & answer→MCQ 31 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : All the sepals together are called corolla.
Reason : The function of sepals is to protect the flower in the bud stage.
- A
Both $A$ and $R$ are true and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true but $R$ is not the correct explanation of the assertion.
- C
$A$ is true but $R$ is false.
- ✓
$A$ is false but $R$ is true.
AnswerCorrect option: D. $A$ is false but $R$ is true.
All the sepals taken together are called calyx.
View full question & answer→MCQ 41 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Internal fertilisation occurs in mammals and birds.
Reason : External fertilisation occurs in reptiles, amphibians and fishes.
- A
Both $A$ and $R$ are true and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true but $R$ is false.
- D
$A$ is false but $R$ is true.
AnswerCorrect option: C. $A$ is true but $R$ is false.
The fertilisation which occurs inside the female body is called internal fertilisation. Reptiles show internal fertilisation.
View full question & answer→MCQ 51 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Sexual reproduction leads to greater variety in population.
Reason : Sexual reproduction plays an important role in the origin of new species.
- A
Both $A$ and $R$ are true and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true but $R$ is not the correct explanation of the assertion.
- C
$A$ is true but $R$ is false.
- D
$A$ is false but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true but $R$ is not the correct explanation of the assertion.
In sexual reproduction the offsprings, although similar to their parents, are not identical to them or to one another. This is because the offsprings receive some genes from the mother and some from the father. Because of the mixing of genes of mother and father in various different combinations, all the offsprings have genetic variations means that a species can adapt more quickly to changes in its environment. This is because there are always likely to be some individuals which are more suited to the changes than others, and these individuals will survive and reproduce themselves.
Sexual reproduction plays an important role in the origin of new species having different characteristics.
View full question & answer→MCQ 61 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Condom protects a person from the sexually transmitted diseases.
Reason : Condom prevents the sperms from meeting the ovum by acting as a barrier.
- A
Both $A$ and $R$ are true and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true but $R$ is not the correct explanation of the assertion.
- C
$A$ is true but $R$ is false.
- D
$A$ is false but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true but $R$ is not the correct explanation of the assertion.
Condoms are used by males. These are rubber or plastic sheaths which are put on penis before copulation. The condom prevents the sperms from meeting the ovum $($or egg$)$ by acting as a barrier between them. The benefit of condom is that it protects a person from syphilis and $\ce{AIDS}.$
View full question & answer→MCQ 71 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Vaginal pills contain spermicides.
Reason : Spermicides kill the sperms.
- A
Both $A$ and $R$ are true and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true but $R$ is not the correct explanation of the assertion.
- C
$A$ is true but $R$ is false.
- D
$A$ is false but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true but $R$ is not the correct explanation of the assertion.
Vaginal pills are the chemical methods of birth control. The vaginal pills contain the chemicals called spermicides, which kill the sperms.
View full question & answer→MCQ 81 Mark
In each of the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as :
Assertion : $\text{DNA}$ acts as the information source.
Reason : It helps in making different proteins and cellular machinery of the cell.
- ✓
If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
- B
If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
- C
If assertion is true, but Reason is false.
- D
If assertion is false, but Reason is true.
AnswerCorrect option: A. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
The major function of $\text{DNA}$ is to encode the sequence of amino acid residues in proteins, using the genetic code. To read the genetic code, cells make a copy of a stretch of $\text{DNA}$ in the nucleic acid $\text{RNA}.$
View full question & answer→MCQ 91 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Spore formation is found in unicellular organisms only.
Reason : Rhizopus and Mucor reproduce by spore formation method.
- A
Both $A$ and $R$ are true and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true but $R$ is not the correct explanation of the assertion.
- C
$A$ is true but $R$ is false.
- ✓
$A$ is false but $R$ is true.
AnswerCorrect option: D. $A$ is false but $R$ is true.
The spore formation method of asexual reproduction occurs in both unicellular and multicellular organisms. E.g., Bacteria, Fungi, Ferns and Mosses reproduce by spore formation method.
View full question & answer→MCQ 101 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below:
Assertion : The testes are present outside the abdominal cavity of the body.
Reason : Sperm formation requires a lower temperature than the normal body temperature.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
The testes of a man lie in the small muscular pouch called scrotum outside the abdominal cavity. Being outside the abdominal cavity, the temperature of scrotum is about $2-3^\circ C$ lower than the normal body temperature. It is because the sperm formation requires a lower temperature than the normal body temperature. So, the testes provide an optimal temperature for formation of sperms.
View full question & answer→MCQ 111 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Regeneration is getting a full organism back from its body parts.
Reason : Hydra and Planaria show regeneration.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
Regeneration is the process which involves repair of damaged cells/ tissue or replacement or redevelopment of broken body part or reconstruction of whole body from a small body fragment. The simple animals like Hydra and Pianaria show regeneration. It means if Hydra or Pianaria somehow get cut into a number of pieces, then each body piece can grow into a complete organism.
View full question & answer→MCQ 121 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Fusion of gametes gives rise to a single cell called zygote.
Reason : Zygote is a fertilised ovum.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
The fusion of a sperm with an ovum to form a zygote during sexual reproduction is called fertilisation. The zygote is fertilised ovum or fertilised egg. The zygote grows and develops to form a new baby.
View full question & answer→MCQ 131 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Ovaries are the primary reproductive organs in a woman.
Reason : The function of ovaries is to make mature female sex cells and female sex hormones.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
Ovaries are small sized, almond $-$ shaped, abdominal in position. These are the primary sex organs of female. Ovaries forms ova by oogenesis from germ cells of ovary and secrete female hormones estrogen and progesterone.
View full question & answer→MCQ 141 Mark
Directions : In the following questions, the Assertions $(A)$ and Reason $(s)\ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion $(A) : $ Spores are unicellular bodies.
Reason $(R) : $ The parent body simply breaks up into smaller pieces on maturation.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 151 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Self $-$ pollination occurs when the pollen grains from the anther of a flower are transferred to the stigma of same flower or another flower on the same plant.
Reason : Insects and wind help in autogamy.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: C. $A$ is true, but $R$ is false.
Insects help in cross $-$ pollination. When an insect sits on the flower of a plant for sucking nectar then the pollen grains from anther of the flower stick to its body and when this insect sits on another flower of similar plant, pollen grains sticking to its body are transferred to the stigma of another flower. In this way, the insect transfers the pollen grains from the anther of flower in one plant to the stigma of flower in another plant and causes cross $-$ pollination. The blowing wind also carries pollen grains from one flower to another flower and helps in cross pollination.
View full question & answer→MCQ 161 Mark
In each of the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as :
Assertion : $\text{AIDS}$ is an incurable and a fatal bacterial infection.
Reason : It suppresses the immune system of the body.
- A
If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
- B
If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
- C
If assertion is true, but Reason is false.
- ✓
If assertion is false, but Reason is true.
AnswerCorrect option: D. If assertion is false, but Reason is true.
Suppressed Immune System: The immune system can be weakened or suppressed by certain cancers, $\text{UV}$ radiation, special drugs for organ transplants, and the human immunodeficiency virus $\text{(HIV)}$ that causes $\text{AIDS}$. When the immune system is not functioning properly, we are at risk to develop cancer as well as infections.
View full question & answer→MCQ 171 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Seeds are matured ovules.
Reason : The part of seed which contains stored food for baby plant is called cotyledon.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
Ovule is gradually converted into a seed. A seed is the reproductive unit of a plant. The seed contains a baby plant $($or embryo$)$ and food for the baby plant. The part of baby plant in seed which develops into shoot with leaves is called plumule and the part which develops into root is called radicle. The part of seed which contains stored food for the baby plant is called cotyledon.
View full question & answer→MCQ 181 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Stock is the lower part of a plant having the roots.
Reason : In grafting, the stock is placed over the scion.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: C. $A$ is true, but $R$ is false.
Grafting is a method in which the cut stems of two different plants $($one with roots and other without roots$)$ are joined together in such a way that the two stems join and grow as a single plant. Stock is the lower part of a plant $($or tree$)$ having the roots. Scion is the upper part of a plant which may have leaves on it $($but no roots$).$
View full question & answer→MCQ 191 Mark
In each of the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as :
Assertion : Menstruation is the regular discharge of blood from the thick uterine lining.
Reason : Menstruation occurs when egg is fertilized by sperm.
- A
If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
- B
If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
- ✓
If assertion is true, but Reason is false.
- D
If assertion is false, but Reason is true.
AnswerCorrect option: C. If assertion is true, but Reason is false.
The most common cause of discharge after your period is old blood that's still being expelled from theuterine lining. This can occur within a few days after your normal flow has already stopped, and tends to be brownish in color.
If the egg is fertilized by a sperm as it travels down the fallopian tube, then pregnancy occurs. The fertilized egg attaches to the lining of the uterus. The placenta then develops. If the egg does not become fertilized, the lining of the uterus $($endometrium$)$ is shed during menstruation.
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