Biology CUET UG 26-05-2023 Shift 3 Paper

Earthworms, sponges, tapeworms, and leeches possess both male and female reproductive organs in the same individual and are classic hermaphrodites (monoecious / bisexual). Cockroach is a dioecious (unisexual) species having distinct male and female individuals.

Matching of reproductive botanical terms:

• Polyembryony: Occurrence of more than one embryo in a seed, characteristically found in citrus varieties like Orange (A-III).
• Parthenocarpy: Development of fruits without fertilization, as in seedless Banana (B-IV).
• False fruit: Fruits where thalamus contributes to fruit formation, such as Apple and strawberry (C-I).
• Embryo sac: Represents the 7-celled, 8-nucleate female gametophyte of angiosperms (D-II).

In flowering plants, embryo development (embryogeny) follows a conserved progression:

• Syngamy leads to the formation of the diploid zygote.
• The zygote divides to form the proembryo and subsequently the (D) Globular embryo.
• The globular stage transitions into the (A) Heart-shaped embryo.
• Further differentiation leads to the (B) Typical mature dicot embryo with two cotyledons, plumule, and radicle.

Placenta also acts as an endocrine tissue and produces several hormones like human chorionic gonadotropin (hCG), human placental lactogen (hPL), estrogens, progestogens, and relaxin.

Luteinising hormone (LH) is secreted by the anterior pituitary gland, not by the placenta.