Speciation

Question 1

Explain about continuous variation

Answer 1

-has no distinct categories and show continuous range of trait characteristics
-Ex:body weight,height of human
-it is a quantitative,can be measured from one extreme to another
-can be affected by enviroment
-affected by polygene
-show normal distribution curve

Question 2

Explain about discontinuous variation

Answer 2

-has discrete values and shows non continuous range of characteristics
-Discontinuous variation occurs when a characteristic is either present or absent and there is no intermediate
-ex-blood group,rolling tounge,colour of flower
-cannot be measured and graded from one extreme to another
-controlled by one gene
-not affected by enviroment
-show discrete distribution

Question 3

Explain the importance of variation

Answer 3

-variation provide adaptations for the organisms to survive in everchanging enviroment
-variation provides raw material for the process of natural selection
-the population with little varation has less chance of surviving in a changing enviroment.
-variation enables a population to survive in a wide range

Question 4

what is variation

Answer 4

it is the diffences between organisms of the same species

Question 5

what is natural selection

Answer 5

Natural selection is the process by which certain traits or characteristics become more or less common in a population over generations.

Question 6

Explain the key principles in natural selection

Answer 6

-Variation: Every population of organisms contains individuals that vary in their traits. For example, in a population of beetles, some may be green, while others are brown.

-Heritability: Traits that give an organism an advantage (such as better camouflage, speed, or resistance to disease) can be passed down to the next generation through genes.

-Differential Reproduction: Not all individuals in a population are equally successful at surviving and reproducing. Organisms with traits better suited to their environment are more likely to survive longer, find food, escape predators, and reproduce.

-Time: Over long periods, these small advantages accumulate, and the population changes. Traits that improve an organism’s fitness become more common, while those that reduce fitness become rare or disappear.

Question 7

what are the main types of natural selectrion

Answer 7

-stabilising selection
-disruptive selection
-directional selection
-sexual selection
-polymorphism