The thread-like structures on which sporangia develop are called hyphae. Their scientific name is sporangiophore.

Asexual reproduction in penicillium takes place by conidia or conidiospores which are developed on conidiospores. When food is plentiful, hydra reproduce asexually by producing buds in the body wall, which grow to be miniature adults and simply break away when they are mature. Gemmules are internal buds found in sponges that are the result of asexual reproduction in response to a hostile environment. In chlamydomonas, asexual reproduction goes through zoospores, palmella stage, alpanospores and hypnospores.

Disease-free plants can be produced by tissue culture. In this technique, we can take few healthy cells and selectively multiply them to form new plants under sterile and aseptic conditions. But, in grafting or layering or cutting, the chances of having diseased plants are there because the cells cannot be selectively chosen in these and at any time, the pathogens may attack them.

Vegetative propagation in bryophyllum occurs through leaves. 

Buds grow on the parent body and gradually form a new individual. Hence, (3), i.e. budding, is correct. In fission and regeneration, new individuals separate out and there is no parent organism. In spore formation, spores develop on the parent body but they form new individuals after they fall on suitable substratum away from the parent body.

Vegetative propagation means formation of new plants from vegetative parts.

Penicillium reproduces with the help of non-motile spores called conidia.

The process of formation of seeds without fertilisation is known as apomixis.

Statement (a) is correct. A single parent is involved. Statement (b) is wrong. It does not involve formation and fusion of gametes. Statement (c) is wrong. It involves only mitotic divisions. Statement (d) is correct. All individuals produced are genetically identical, i.e. clone.

Spore formation is a common mode of reproduction in fungi, like bread moulds, i.e. rhizopus. Leishmania and paramecium reproduce by binary fission, while planaria forms new individuals by regeneration method.

We know that apple, pear and peach have seeds. It is only banana that is seedless and has lost the capacity to produce seeds. In case of apple, the ability to produce seeds is there but they may not be viable.