The wood in a matchstick is made of cellulose, a polymer of glucose molecules. When you light the matchstick, heat and light are given off, indicating that an exothermic reaction is occurring.
There are two types of reactions:
1. Exothermic reactions: In these reactions, the reactants combine to form product and heat is liberated. Example, burning of fuel.
2.Endothermic reactions: In these reactions, the reactants combine to form product and heat gets absorbed from the surroundings. Example, photosynthesis in plants where the energy of the Sun gets absorbed.
<span> COMPLETE DOMINANCE:
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<span>Mendel concluded that some alleles are dominant and others are recessive. When one dominant allele is present, it's enough to make the recessive allele unexpressed (this is what happens in heterozygous individuals). In other words, it 'hides' or masks the recessive allele.
CO-DOMINANCE:
-a condition in which both alleles are dominant.
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There are alleles that have the capacity of dominating at the same time, and when an organism is heterozygotic, both alleles are expressed.
For example, a white chicken(WW) crossed with a black chicken (BB): 100% of the offspring being WB. With this genotype, they have black feathers and white feathers.
It's not a blend of colors, but a case where both are expressing.
INCOMPLETE DOMINANCE:
-a condition with none of the alleles is dominant or recessive, so the traits blend in the phenotype.
Some alleles are not completely dominant, and when that's the case the phenotype of a heterozygous organism will be a mix between the phenotypes of its homozygous parents.
For example:
plant 1: RR -red
plant 2: rr- white
By crossing this plants we will obtain 100% of the offspring with a color mix: pink.(genotype: Rr)
Red and white are not completely dominating so it results in a blend of colors.
SEX LINKED TRAITS
Sex chromosomes contain genes that determine the sex of a person. Two X chromosomes result in a female and one X plus a Y result in a male.
In those chromosomes, there are genes specific for each gender, and in those chromosomes, there are genes that code for certain traits- the sex-linked traits.
These traits will be inherited according to the sex chromosomes they receive from their parents.
In today's society, the theory of Darwin - the theory of evolution, which states that all organisms have evolved from simple organisms to more and more complex organisms all the way to us, is favoured and viewed as something that seems to be true, at least when considering all the available evidence.
