Answer:
After C14, Uranium238 is most widely used mineral in geological or archaeological dating.
Explanation:
U238 is generally used to date the rock materials, to know the age. As we know the half-life of U238, it is easy to identify the age of the materials containing uranium 238. It can be called as absolute dating method as it determines the exact age of the uranium contained material. It is a type of radiometric dating.
Answer:
1. Character
2. Trait
3. Monohybrid cross
4. Alleles
5. Dominant allele
6. Recessive allele
7. Phenotype
8. Genotype
Explanation:
1. Character is an inherited feature passed through genes that varies in individual e.g flower colour
2. A trait is the variant form of a character e.g red and blue flower colour are variant forms of the flower colour character.
3. Monohybrid cross is a cross between two parents differing in only one character.
4. Allele is an alternate form of a gene e.g A and a alleles for gene A
5. Dominant allele is one of the allelic pair that expresses itself by masking the expression of the other allele in a heterozygous state.
6. A recessive allele is the allele that is masked or not expressed in a gene. It is covered up by the presence of the dominant allele.
7. Phenotype is the physical and visible trait of an organism e.g Tallness, colour
8. Genotype is the genetic constituent of an organism e.g AA, Aa etc.
Answer:
The chemical basis of Chargaff"s rule is the bonding properties of the DNA bases.
Explanation:
According to the Chargaff"s rule in a DNA molecule the total number of purine bases are equal with the total number of pyrimidine bases that means
Adenine +Guanine=Thymine +Cytosine
In simple words the rule is based on the 1:1 ratio of both purine and pyrimidine bases.
Options for the question have not been provided. They are as follows:
(1) DNA in muscle cells
(2) base sequences in liver cells
(3) genes in an egg cell
(4) number of chromosomes in a fetal bone cell
Answer:
(3) genes in an egg cell
Explanation:
Evolution is the change in characteristics of a species which it develops over the time. These changes can be a result of natural selection, genetic drift, founder effect etc. They are passed from one generation to another hence the alleles for them get fixed in the population.
For evolution to occur, change should take place in germ cells. Germ cells are the one which fuse to form the organisms of next generation. If there is a change in their genes, it would also appear in next generation, unlike changes in genes of somatic cells. Since egg cell is a germ cell it is the correct answer.
