Science [1 Mark Questions]

Zygote is the first diploid structure. It undergoes mitotic divisions to form embryonal cells. Embryonal cells further divide by mitosis to form the adult. Mitosis maintains the same chromosome number in the daughter cells.

Planaria exhibits regeneration. If its body is cut into two vertical halves, each piece of the body of Planaria grows into a complete individual.

Pollination is transfer of pollen from one flower to the stigma of same/ other flower of same or another plant. It takes place after gamete formation. Only after arrival of pollen grains on stigma and entry of pollen tube (carrying the male gametes) into ovary, male gamete can fuse with female gamete (ovum). Ovum is present in ovule and ovule is present in ovary.
Therefore, the zygote is present inside the ovule.

A true copy of anything is called a clone. In case of asexual reproduction, genes are contributed by a single parent. Due to this, offsprings produced by asexual reproduction are clones of their parent.

Yeast is a fungus and needs a supply of energy for its living and growth. Sugar supplies this energy. (Your body also gets much of its energy from sugar and other carbohydrates.) Water does not provide required nutrition. Yeast can use oxygen to release the energy from sugar.

Growth of Bread Mould requires both water and nutrients. Dry slice of bread contains nutrients but no water. Therefore, Bread Mould does not grow over it. Moist slice possesses both water and nutrients. Hence, Bread Mould grows over it.

Unicellular organisms reproduce by asexual reproduction which is simple division of parent cell into two daughter cells. Now, these two daughter cells grow into mature organism. Hence, cell division can be considered as mode of reproduction in single celled organisms. Eg: Amoeba.