Heredity-1 Flashcards
what does inheritance provide
Inheritance from the previous generation provides both a common basic body design, and subtle changes in it, for the next generation.The second generation will have differences
that they inherit from the first generation, as well as
newly created differences .
how is variation in asexual reproduction
If one bacterium divides, and then the
resultant two bacteria divide again, the four individual
bacteria generated would be very similar. There would
be only very minor differences between them, generated
due to small inaccuracies in DNA copying. However, if
sexual reproduction is involved, even greater diversity
will be generated, as we will see when we discuss the
rules of inheritance
Do all these variations in a species have equal
chances of surviving in the environment in which they
find themselves?
Depending on the
nature of variations, different individuals would have different kinds of advantages. Bacteria that can withstand heat will survive
better in a heat wave
define variation
The presence of difference in morphological, physiological and other traits among organisms of the same species is called variation.
Why do all variations do not provide a species with an equal chance of survival?
i) I may lead to the death of an organism
Some variations that arise as a result of abnormal change to a crucial gene may lead to the death of an organism.
ii) only some variations provide evolutionary benefits
Variations are random. Only a few types of variation can provide survival advantages to an organism or species. Some variations may be unfit for a type of environment.
Why is it that only a few of the many variations generated in a species get passed on through generations?
Only some variations provide survival advantages.
Variations are random. Depending on the environment, only some variations provide survival advantages to an organism.
Some variations are deadly.
Some variations arise as a result of abnormal changes to crucial genes. This might cause the death of the organism.
Some variations decrease the adaptability of organisms to their environment.
Because variations are random, some of them might make an organism unfit for its environment.
How does the creation of variations in a species promote survival?
Variations in a species arise due to errors in the DNA copying. Force of Natural Selection selects the organisms with useful variations in the previaling environment so as to ensure their survival. These individuals with useful variations increase in numbers through differential reproduction in the population.
what is natural selection
Natural selection is the mechanism through which living creature populations adapt and change.
It states that the organisms that are able to survive and reproduce with the changing environmental conditions are selected by nature while the ones that cannot survive are eliminated.
define mutation
sudden changes in the genetic form of an organism which re passed on to the next generation are called mutations. they cause variations in organims
what is the significance of variation
some variations may act as a preadaptation to the harsh environmental conditions. Ex: heat wave may kill most bacteria except a few which may survive with a preadaption to tolerate high temps
-raw material for evolution
-useful variation provide survival advantages to organism in the prevailing environment.
