Bank of Biology Class 1️⃣2️⃣

Bank of Biology Class 1️⃣2️⃣

5/21/2025, 6:03:56 AM

1️⃣2️⃣ Assertion A: The first stage of gametophyte in the life cycle of moss is protonema stage. Reason R: Protonema develops directly from spores produced in capsule.

Bank of Biology Class 1️⃣2️⃣

5/21/2025, 6:03:28 AM

*Q:11 Correct Answer* ✅ *(3) A is true but R is false* > *Explanation:* In bryophytes (like mosses and liverworts), the gametophyte is the dominant, green, and photosynthetic phase of the life cycle. The sporophyte, however, is not free-living; it is dependent on the gametophyte for nutrition and support, as it remains attached to it throughout its life.

Bank of Biology Class 1️⃣2️⃣

5/23/2025, 5:50:54 AM

*Q:13 Correct Answer* ✅ *(4) A is false but R is true* > *Explanation:* In pteridophytes (e.g., ferns), the sporophyte is the dominant and long-lived phase of the life cycle, not the gametophyte. However, pteridophytes do exhibit alternation of generations, where both the sporophyte and gametophyte are independent, although the gametophyte is small and short-lived. So, Assertion is false but the Reason is true.

Bank of Biology Class 1️⃣2️⃣

5/22/2025, 4:12:43 AM

*Q:12 Correct Answer* ✅ *(1) Both A and R are true and R is the correct explanation of A* > *Explanation:* In mosses, the protonema is the first stage of the gametophyte generation — it is a filamentous, green structure that resembles algae. It develops directly from spores that are released from the capsule of the sporophyte. This stage eventually gives rise to the leafy gametophyte through buds.

Bank of Biology Class 1️⃣2️⃣

5/20/2025, 5:28:28 AM

*Q:10 Correct Answer* ✅ *(1) Both A and R are true and R is the correct explanation of A* > *Explanation:* Red algae (Rhodophyta) are commonly found in deeper parts of the ocean because they possess phycoerythrin pigment which efficiently absorb blue-green wavelengths of light. These wavelengths penetrate deeper into water, allowing red algae to perform photosynthesis even at considerable depths.

Bank of Biology Class 1️⃣2️⃣

5/22/2025, 4:13:14 AM

1️⃣3️⃣ Assertion (A): In pteridophytes, the gametophyte is the dominant and long-lived phase of the life cycle. Reason (R): Pteridophytes exhibit alternation of generations with independent gametophyte and sporophyte phases.

Bank of Biology Class 1️⃣2️⃣

5/23/2025, 1:36:20 PM

*Q:14 Correct Answer* ✅ *(3) A is true but R is false* > *Explanation:* In gymnosperms, pollen grains are indeed released from the microsporangium and transported by air currents to reach the ovule. However, the Reason is false because while air helps in pollination, a pollen tube is formed in gymnosperms after the pollen reaches the ovule. The pollen tube delivers the male gametes to the archegonia for fertilization.

Bank of Biology Class 1️⃣2️⃣

5/23/2025, 5:55:13 AM

1️⃣4️⃣ Assertion: In gymnosperms, the pollen grains are released from the microsporangium and carried by air currents. Reason: Air currents carry pollen grains to the mouth of the archegonia where male gametes are discharged and pollen tube is not formed.

Bank of Biology Class 1️⃣2️⃣

5/20/2025, 5:29:05 AM

1️⃣1️⃣ Assertion (A): In bryophytes, the gametophyte is the dominant and photosynthetic phase of the life cycle. Reason (R): The sporophyte of bryophytes is free-living and independent of the gametophyte.

Bank of Biology Class 1️⃣2️⃣

5/18/2025, 2:44:02 PM

1️⃣0️⃣ Assertion (A): Red algae can live in deep marine waters. Reason (R): Red algae possess phycoerythrin pigments, which can absorb blue-green light that penetrates deeper into the ocean.