Answer:
Variation, in biology, any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences (genotypic variation) or by the effect of environmental factors on the expression of the genetic potentials (phenotypic variation). Variation may be shown in physical appearance, metabolism, fertility, mode of reproduction, behaviour, learning and mental ability, and other obvious or measurable characters.
chromosomes or by differences in the genes carried by the chromosomes. Eye colour, body form, and disease resistance are genotypic variations. Individuals with multiple sets of chromosomes are called polyploid; many common plants have two or more times the normal number of chromosomes, and new species may arise by this type of variation. A variation cannot be identified as genotypic by observation of the organism; breeding experiments must be performed under controlled environmental conditions to determine whether or not the alteration is inheritable.
Genotypic variations are caused by differences in number or structure of Environmentally caused variations may result from one factor or the combined effects of several factors, such as climate, food supply, and actions of other organisms. Phenotypic variations also include stages in an organism’s life cycle and seasonal variations in an individual. These variations do not involve any hereditary alteration and in general are not transmitted to future generations; consequently, they are not significant in the process of evolution.
Explanation:
Brainliest please?
Similarities
Both plant and animal cells have eukaryotic origins
Both have common organelles like the nucleus, mitochondria and ribosomes
Both are surrounded by a cell membrane
differences
plant cells have a regular defined shape while animal cells have an irregular shape
plant cells have a cell wall while animal cells lack a cell wall
plant cells have a chloroplast for photosynthesis while animal cells do not have a chloroplast
A true
<span> Before agriculture was developed people mostly were nomadic in nature. They moved from place to place in search of food. Some of them were groups of hunter gatherers as well. When agriculture started people also started to settle down in groups. This led to the development of civilization and in modern day cities and towns. The first agricultural practices were started beside the river banks due to the reason that the soil was very fertile and water for irrigation was also easily available. </span>
