Botany and Plant Science

Correct Answer: have parallel venation

The essential parts of a flower are the androecium (male reproductive whorl - stamens) and gynoecium (female reproductive whorl - carpels). These are called 'essential' because they are directly involved in sexual reproduction - stamens produce and release pollen, while carpels contain ovules that develop into seeds after fertilization. The calyx (sepals) and corolla (petals) are 'accessory' or 'non-essential' parts that protect the reproductive organs and attract pollinators, but flowers can still complete sexual reproduction without them (as in grasses and some wind-pollinated species).

The reproductive parts of a flower are stamens (male) and carpels (female). Stamens (collectively called androecium) produce pollen grains containing male gametes, while carpels (collectively called gynoecium) contain ovules with female gametes. These structures are directly involved in sexual reproduction - pollination, fertilization, and seed formation. Sepals and petals (which make up calyx and corolla) are non-reproductive, accessory parts that protect the bud and attract pollinators respectively. Flowers can exist without sepals and petals (as in grasses), but cannot function in sexual reproduction without stamens and/or carpels.

Papaya (Carica papaya) is unisexual, meaning individual plants bear either male or female flowers separately (dioecious species). Papaya plants can be male (staminate flowers only), female (pistillate flowers only), or bisexual (hermaphrodite) depending on genetic and environmental factors. In contrast, hibiscus, mustard, and rose are bisexual (perfect flowers) - each flower contains both stamens and carpels. Unisexual flowers are an adaptation to promote cross-pollination and prevent self-pollination, increasing genetic diversity in offspring. The presence of separate male and female plants is called dioecy.

Stamen is the male reproductive part of a flower, consisting of anther (which produces pollen) and filament. Carpel (or pistil) is the female reproductive part containing ovary. Sepals and petals are accessory/sterile parts that protect and attract pollinators respectively, but are not directly involved in reproduction.

After fertilization, the ovary develops into the fruit while the ovules become seeds. This is a fundamental concept in plant biology - fruit is essentially the ripened ovary. Sepals, stamens, and carpels do not develop into fruit; carpels contain the ovary but the ovary itself is what transforms.

Pneumatophores are called breathing roots.

Scalariform conjugation requires association of two different filaments lined side by side, either partially or throughout their length. Zygospores are present either near the centre or lateral filaments if 3 filaments are conjugating by scalariform conjugation.

In red algae, male sex organ is spermatangium and female sex organs are carpogonium with trichogyne.

Rhizoids are unicellular and arise in gametophytes. They do not have any vascular bundles. However, roots are multicellular and arise in sporophytes.They possess vascular bundles for transport.

Root hairs are extension of epidermal cells.

Casparian strip is composed of a wax like substance called suberin, which blocks water and solute movement through the endodermis.

Biotin, thiamine and co-enzyme A are sulphur-containing vitamins.

Mistletoe is a partial stem parasite. It depends upon the host stem just for water and minerals.