Vardaan Learning Institute

Ans: (d) Anther of one flower to Stigma of another flower (same one)
For fertilization to occur, pollination must happen within the same species.

Ans: (c) Vas deferens
Vas deferens is part of the male reproductive system (sperm duct).

Ans: (d) Pollen grains
Anther produces pollen grains (male gametophytes).

Ans: (b) Condoms
Barrier methods like condoms prevent fluid exchange, thus protecting against STDs.

Ans: (b) Leaf
Bryophyllum reproduces via buds produced in the notches along the leaf margin.

Ans: (b) Uterus
The fertilized egg (zygote) gets implanted in the lining of the uterus.

Ans: (b) Binary fission
During favourable conditions, Amoeba divides into two daughter cells (Binary fission).

Ans: (b) Rhizopus
Rhizopus (Bread Mould) reproduces by forming spores in sporangia.

Ans: (b) Yeast
Yeast reproduces asexually by budding.

Ans: (a) Fragmentation
Spirogyra breaks up into smaller fragments upon maturation, each growing into a new individual.

Ans: (b) Both A and R are true but R is not the correct explanation of A.
Spores are unicellular. They grow into new plants. Both statements are true but R doesn't explain why they are unicellular.

Ans: (a) Both A and R are true and R is the correct explanation of A.
Sperm formation needs a lower temperature than body temp, so testes are located outside in the scrotum.

Ans: (a) Both A and R are true and R is the correct explanation of A.
Fusion of gametes from two different parents combines DNA from two sources, leading to greater variation.

Ans: (b) Both A and R are true but R is not the correct explanation of A.
A is true (plants that lost seed capacity). R is true (faster growth). But R is another advantage, not the explanation for A.

Fragmentation: Organism breaks into pieces, each grows into new individual (e.g., Spirogyra). Occurs in multicelluar organisms with simple body organization.
Regeneration: Ability to repair injured parts or grow a whole organism from a cut part (e.g., Planaria). Carried out by specialized cells.

(i) DNA contains hereditary information. Copying ensures that daughter cells receive the same genetic blueprint for similar body design.
(ii) Variations help a species survive in changing environmental niches (e.g., temperature resistance). Individual may die, but species survives.

(i) Placenta is a disc-like tissue connecting embryo to mother's uterine wall. It provides glucose and oxygen to embryo and removes waste ($CO_2$, urea) from embryo to mother's blood.
(ii) Menstruation: The thick uterine lining breaks down and is discharged along with blood and mucus.

Methods: Mechanical barriers (Condom), Chemical (Pills), IUCD (Copper-T), Surgical (Vasectomy/Tubectomy).
Effect: Helps in family planning (spacing children), prevents unwanted pregnancies, improves mother's health, and barrier methods prevent STDs. Small family leads to better economic prosperity.

Changes: 1. Breast enlargement and darkening of nipple skin. 2. Onset of menstruation (Menarche). 3. Growth of hair in armpits and genital region. 4. Deposition of fat in thighs and hips.

AIDS: Acquired Immuno Deficiency Syndrome. Caused by HIV (Human Immunodeficiency Virus).
Transmission: 1. Sexual contact with infected person. 2. Blood transfusion from infected person.

(i) (Diagram required: Stamen (Anther, Filament), Carpel (Stigma, Style, Ovary), Petals, Sepals).
(ii) Self-pollination: Pollen transfer within same flower or same plant.
Cross-pollination: Pollen transfer to a flower on a different plant of same species (requires agents like wind/insects).

(i) (Diagram required).
(ii) (a) Fertilized: Zygote forms, implants in uterus, placenta develops, pregnancy follows.
(b) Not Fertilized: Uterine lining sheds (Menstruation) after about 14 days of ovulation (Cycle is 28 days).

(i) Male: Pollen grain (generates male germ cells). Female: Egg cell (Ovum).
(ii) Syngamy is the fusion of one male gamete with the female gamete (egg) to form Zygote.
(iii) Double Fertilization: One male gamete fuses with egg (Syngamy) $\rightarrow$ Zygote. Second male gamete fuses with two polar nuclei $\rightarrow$ Endosperm (Triploid). Two fusions occur, hence double fertilization.

(i) 9 months (280 days).
(ii) Testosterone.
(iii) Waste substances generated by the embryo are removed by transferring them into the mother's blood through the placenta (diffusion).