reproduction (image)

Human ovaries are a pair of almond shaped structures about 3cm long, 1.5cm wide lying one on either side of the vertebral column in the abdominal cavity. Each ovary is attached to the dorsal abdominal wall by a mesentery called mesovariu..

The chromosomes line up at the equator of the cell forming a single metaphase plate (as in mitosis). fig. 17.8 - Stages of Meiosis-..

It is the division of cytoplasm. It occurs in animal cells by the appearance of a furrow in the middle of the cell. The furrow deepens and divides the cell into two. Two daughter cells are formed. fig. 17.4 - Differences between Mitosis in Plant and Animal ce..

The process of joining together parts of two different plants of closely related varieties in such a manner that they live as one plant is called grafting. This is usually practiced among dicotyledonous plants, especially fruit trees. Of the 2 plants, one is rooted in the soil and is known as the s..

Roots of some plants develop new plants either by directly producing shoots or producing buds. Shoots are produced by roots of woody plants like Dalbergia, Murraya etc. Adventitious buds are formed on the roots of plants like sweet potato, dahlia, asparagus, tapioca, etc. These buds detach from the..

Reproduction occurs by vegetative propagation, asexual and sexual reproduction. Vegetative propagation through artificial method can be done by cuttings, layering and grafting. Pollination refers to the transference of pollen grains from the anther of a flower to the stigma of t..

At about the age of 10 to 13 years, the ovaries of females are stimulated by the follicle stimulating hormone (FSH) of the pituitary. This is called the onset of puberty and is accompanied by release of hormones oestrogen and progesterone. These hormones control the production of ova or eggs and ap..

Pistil is the female reproductive unit, and is made up of a basal swollen part called the ovary, astalk called the style and a terminal receptive disc called the stigma. The ovule begins its development as a minute protuberance on the placenta and forms a thick mass of cells termed as the..

External fertilisation takes place in animals like the fish and frog where the eggs are released from the body of the females into the water outside. Frog, Ovulation, Accumulation of Eggs in Uterus, Spawning and External fertilisation These eggs are then fertilised by the sperms produced by the mal..

The sperm generally comes in contact with the ovum at the animal pole. A number of sperms surround the ovum, but only one of them fuses with the egg. Fertilisation of the egg with only one sperm is known as monospermy. Fertilisation occurs in the ampulla of the oviduc..