Question

Questions of Class-9
chapter:-1 ( The fundamental unit of life: Cell )​
subject :- Biology​

Answer 1

Explanation:

Question = why are blue green algae and bacteria are called true cells

Answer = Bacteria are prokaryotic org.anisms that are not considered as true cells because of the following reasons: 1) Bacteria do not have a true nucleus. The DNA in bacteria rather is arranged in single circular strand in its cytoplasm. 2)the organelles in the blue algae also lack membrane unlike other cells.

Questions = what is the unit of measurement is used to measure a cell what is a largest and smallest living cell.

Answer = The unit of measuring the size of a cell is microns.

1 micron= 0.000001 meters or 0.001 millimeters). The largest cell in the hum.an bo.dy is the egg cell. They are spherical in shape. It's measure is about 0.1 millimeters in diameter.

Questions = why do cells have different shapes.

Answer = Cells have different shapes because they do different things. ... The shapes of cells have evolved to help them carry out their specific function in the bod.y, so lo.oking at a cell's sh.ape can give clues about what it does. Neurons are cells in the brain and nervous system.

Answer 2

Explanation:

1. Bacteria are prokaryotic organisms that are not considered as true cells because of the following reasons: 1) Bacteria do not have a true nucleus. The DNA in bacteria rather is arranged in single circular strand in its cytoplasm. 2)the organelles in the blue algae also lack membrane unlike other cells.
2. Micrometre is unit of measurement to measure a cell , The smallest cell is Mycoplasma (PPLO-Pleuro pneumonia like organims). It is about 10 micrometer in size. The largest cells is an egg cell of ostrich.
3. Cells have different shapes because they do different things. Each cell type has its own role to play in helping our bodies to work properly, and their shapes help them carry out these roles effectively. The following cell types all have unusual shapes that are important for their function
4. A cell consists of three parts: the cell membrane, the nucleus, and, between the two, the cytoplasm. Within the cytoplasm lie intricate arrangements of fine fibers and hundreds or even thousands of miniscule but distinct structures called organelles.
5. Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy, and carry out specialized functions