Page 105 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

v Some organisms such as algae have filamentous body that can break into fragments. Each

fragment then develops into a new individual. This type of asexual reproduction is called

fragmentation.
v In spore formation, organisms like fungi, produces hundreds of tiny microscopic stuctures

called spores. Each spore is covered with a hard outer covering which burst only when they
get favourable conditions and start germinating to form new organisms.

v Flowers are the reproductive parts of a plant. Stamen is the male reproductive part & pistil
is the female reproductive part in a flower.

v The anther in the stamen contains pollen grains which produce the male gamete. The ovary
in the pistil contains the female gamete (egg).

v A male & a female gamete when fuse to form a zygote, it is known as sexual reproduction.
v Flowers which contain either pistil or stamen are called unisexual flowers. For example,

papaya.

v Flowers which contain both stamens & pistil are called bisexual flowers. For example, rose.
v The transfer of pollen grains from the anther of a stamen to the stigma of a pistil is called

pollination.
v When pollen grains from the anther of a flower are transferred to the stigma of the same

flower or another flower of the same plant, it is called self pollination.
v When the pollens from the anthers of a flower are transferred to the stigma of a flower of

another plant of the same species, it is called cross pollination.

v The process of fusion of the male & female gametes to form the zygote is called fertilisation.
v After fertilisation, the ovary develops into a fruit, the zygote develops into an embryo and

the seeds develop from the ovules.
v The seed contains a young plant in the form of an embryo, which is protected by a seed

covering called a seed coat.
v Plumule from the seed gives rise to the shoot system & radicle gives rise to the root system.

v Fruits can be of two types– flesh & dry.

v The transfer of seeds from the parent plant to different places is called seed dispersal.
v Seeds are dispersed through various agencies, such as wind, water, birds, animals or by

fruits.
v Botanist Schwann suggested that new plants that can grow outside the parent body if

provided an exact external environment, can be recreated.
v Gottlieb Haberlandt made the first attempt to grow new plants using cells from various

parts of the plant. He was a German botanist. His ideas led to important discoveries in the

field of botany and therefore he is regarded as the father of plant tissue culture.

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