Solution : The cell theory was proposed by two scientists- Botanist Theodor Schleiden (1838) and zoologist Matthias Schwann (1839). Main postulates of the Cell Theory : i) A cell is the smallest structural unit of all living things. ii) A cell is the unit of function of all living things. iii) All cells arise from …
Who propounded the cell theory? Write cell theory. Read More »
We have learnt how the electrons in an atom are arranged in different shells/orbits. The electrons present in the outermost shell of an atom are known as the valence electrons. From the Bohr-Bury scheme, we also know that the outermost shell of an atom can accommodate a maximum of 8 electrons. It was observed that …
The distribution of electrons into different orbits of an atom was suggested by Bohr and Bury. The following rules are followed for writing the number of electrons in different energy levels or shells: (i) The maximum number of electrons present in a shell is given by the formula 2n2 , where ‘n’ is the orbit …
How are Electrons Distributed in Different Orbits (Shells)? Read More »
A vacuole is a membrane-bound cell organelle. In plant cells, vacuoles are generally small and help sequester waste products. help maintain water balance.
A chloroplast is an organelle within the cells of plants and certain algae that is the site of photosynthesis, which is the process by which energy from the Sun is converted into chemical energy for growth.
Plastids are a organelles found in plant cells. Most prominent are the chloroplasts which carry out essential functions such as photosynthesis, the biosynthesis of fatty acids etc .
There is no nuclear membrane. The cells having nuclear material without nuclear membrane are termed prokaryoticcells. The organisms with these kinds of cells are called prokaryotes (pro : primitive; karyon : nucleus). Examplesare bacteria and blue green algae. The cells, like onion cells and cheek cells having well-organised nucleus witha nuclear membrane are designated as …
The entire content of a living cell is known as protoplasm. It includes the cytoplasm and the nucleus. Protoplasm is called the living substance of the cell.
GeneGene is a unit of inheritance in living organisms. It controls the transfer of a hereditary characteristic from parents to offspring. This means that your parents pass some of their characteristics on to you. If your father has brown eyes, you may also have brown eyes. If your mother has curly hair, you might also …
Gene Chromosome carry genes and help in inheritance or transfer of characters from the parents to the offspring. The chromosomes can be seen only when the cell divides.
