biology for grade 7

. The diploid zygote develops into an embryo which remains enclosed within the ovule. The ovule then transforms itself into a seed. The seed remains attached to the megasporophyll and is not enclosed by a fruit. The ripe and dry seeds are shed. Under suitable conditions the seeds germinate and deve..

. The diploid zygote develops into an embryo which remains enclosed within the ovule. The ovule then transforms itself into a seed. The seed remains attached to the megasporophyll and is not enclosed by a fruit. The ripe and dry seeds are shed. Under suitable conditions the seeds germinate and deve..

(7%) - includes hormones, enzymes, globulin antibodies, albumin and fibrinogen. (Blood plasma without fibrinogen and other clotting factors is called Serum and is a yellow watery fluid..

Accumulation of wastes due to its improper disposal is a major problem in our country. The recent Surat plague epidemic is an indication. Population in India has been growing at the rate of 1.7%. With this increase, there has also been an increase in the amount of wastes being produ..

The average size of bacterial cell ranges from 1 mm to 10 mm in length and about 0.7 mm to 1.5 mm in width. The largest bacterium is Beggiatoa mirabilis. It is a few centimeters long and about 30-40 m in diamete..

Systematic work on identifying and naming the many species has been in progress for the last 250 -300 years. But the known and described number of species of all organisms on the earth is between 1.7 and 1.8 million which is just about 15% of the total number existing. New species are bei..

This phase involves the contraction of the 2 auricles, pushing the blood into the respective ventricles. There is no back flow of blood due to the presence of the bicuspid and the tricuspid valves. The atrial systole takes 0.1 second. This is followed by the atrial diastole when both the auricles r..

It is the copulation chamber in females. It is about 7.5 cm long and extends backward in front of the rectum from the cervix. The vaginal opening is situated in the vestibule between the labia minora and the vulva. In the virgin state, a thin membranous diaphragm - the hymen is present at..

Flora refers to plant species and fauna refers to animal species. The term biota includes both plant as well as the domesticated and wild species of animals. Our country has a rich diversity of flora and fauna. There are over 45,000 plant species and 81,251 animal species. It represents about..

The plant body or thallus of blue green algae ranges from unicellular to multicellular, branched forms. There are no flagella but some members exhibit a movement caused by gliding. fig. 8.7 - Types of Cyanobacte..