Give scientific reasons:
(1) In sexual mode of reproduction greater diversities are generated.
(2) Phenotypic and genotypic ratios are different.
(3) In human beings the gametes from the male parent decides the sex of the baby.
(4) Paleontological evidence suggests that invertebrates came into existence before the vertebrates.
Give scientific reasons:
(1) In sexual mode of reproduction greater diversities are generated.
(2) Phenotypic and genotypic ratios are different.
(3) In human beings the gametes from the male parent decides the sex of the baby.
(4) Paleontological evidence suggests that invertebrates came into existence before the vertebrates.
(1) In sexual reproduction, two individuals having different variations combine their DNA to give rise to a new individual. Therefore, sexual reproduction allows more variations, whereas in asexual reproduction, chance variations can only occur when the copying of DNA is not accurate.
Additionally, asexual reproduction allows very less variations because if there are more variations, then the resultant DNA will not be able to survive inside the inherited cellular apparatus.
However, in sexual reproduction, more variations are allowed and the resultant DNA is also able to survive, thus making the variations viable.
(2) Genotype is the genetic constitution of an organism, which includes all genes that are inherited from both the parents. For example TT, Tt, and tt are different genotypes of an organism with reference to their tallness. The ratio of different genotypes produced after a cross is called as genotypic ratio.
Phenotype is the observable trait or characteristic of an organism, which is the result of genotype. For example, tallness (TT) and shortness (tt) are phenotypes resulting from different genotypes. The ratio of different phenotypes produced after a cross is called as phenotypic ratio. Thus phenotypic ratios are always different from the genotypic ratio.
(3) In human beings, the females have two X chromosomes and the males have one X and one Y chromosome. Therefore, the females are XX and the males are XY.
The gametes receive half of the chromosomes. The male gametes have 22 autosomes and either X or Y sex chromosome.
Type of male gametes: 22+X OR 22+ Y.
However, since the females have XX sex chromosomes, their gametes can only have X sex chromosome.
Type of female gamete: 22+X
Thus, the mother provides only X chromosomes. The sex of the baby is determined by the type of male gamete (X or Y) that fuses with the X chromosome of the female.
(4) When land was excavated, paleontological evidence i.e., fossils were obtained from the deep layers of the Earth. The systematic study of these fossils proved that they belonged to invertebrates. The layers present above them had fossils resembling to reptiles, birds, amphibians. This suggests that invertebrates came into existence before vertebrates.
(1) In sexual reproduction, two individuals having different variations combine their DNA to give rise to a new individual. Therefore, sexual reproduction allows more variations, whereas in asexual reproduction, chance variations can only occur when the copying of DNA is not accurate.
Additionally, asexual reproduction allows very less variations because if there are more variations, then the resultant DNA will not be able to survive inside the inherited cellular apparatus.
However, in sexual reproduction, more variations are allowed and the resultant DNA is also able to survive, thus making the variations viable.
(2) Genotype is the genetic constitution of an organism, which includes all genes that are inherited from both the parents. For example TT, Tt, and tt are different genotypes of an organism with reference to their tallness. The ratio of different genotypes produced after a cross is called as genotypic ratio.
Phenotype is the observable trait or characteristic of an organism, which is the result of genotype. For example, tallness (TT) and shortness (tt) are phenotypes resulting from different genotypes. The ratio of different phenotypes produced after a cross is called as phenotypic ratio. Thus phenotypic ratios are always different from the genotypic ratio.
(3) In human beings, the females have two X chromosomes and the males have one X and one Y chromosome. Therefore, the females are XX and the males are XY.
The gametes receive half of the chromosomes. The male gametes have 22 autosomes and either X or Y sex chromosome.
Type of male gametes: 22+X OR 22+ Y.
However, since the females have XX sex chromosomes, their gametes can only have X sex chromosome.
Type of female gamete: 22+X
Thus, the mother provides only X chromosomes. The sex of the baby is determined by the type of male gamete (X or Y) that fuses with the X chromosome of the female.
(4) When land was excavated, paleontological evidence i.e., fossils were obtained from the deep layers of the Earth. The systematic study of these fossils proved that they belonged to invertebrates. The layers present above them had fossils resembling to reptiles, birds, amphibians. This suggests that invertebrates came into existence before vertebrates.
