Locus is a fixed position on a chromosome, which is occupied by a single or more genes. Heterozygous organisms contain different alleles for an allelic pair. Hence, a diploid organism, which is heterozygous at four loci, will have four different contrasting characters at four different loci. For exaRead more
Locus is a fixed position on a chromosome, which is occupied by a single or more genes. Heterozygous organisms contain different alleles for an allelic pair. Hence, a diploid organism, which is heterozygous at four loci, will have four different contrasting characters at four different loci.
For example, if an organism is heterozygous at four loci with four characters, say Aa, Bb, Cc, Dd, then during meiosis, it will segregate to form 8 separate gametes.
If the genes are not linked, then the diploid organism will produce 16 different gametes. However, if the genes are linked, the gametes will reduce their number as the genes might be linked and the linked genes will be inherited together during the process of meiosis.
(a) Dominance and Recessive:- Dominance:- 1. A dominant factor or allele expresses itself in the presence or absence of a recessive trait. 2. For example, tall plant, round seed, violet flower, etc. are dominant characters in a pea plant. Recessive:- 1. A recessive trait is able to express itself onRead more
(a) Dominance and Recessive:-
Dominance:-
1. A dominant factor or allele expresses itself in the presence or absence of a recessive trait.
2. For example, tall plant, round seed, violet flower, etc. are dominant characters in a pea plant.
Recessive:-
1. A recessive trait is able to express itself only in the absence of a dominant trait.
2. For example, dwarf plant, wrinkled seed, white flower, etc. are recessive traits in a pea plant.
(b) Homozygous and Heterozygous:-
Homozygous-
1. It contains two similar alleles for a particular trait.
2. Genotype for homozygous possess either dominant or recessive, but never both the alleles. For example, RR or rr
3. It produces only one type of gamete.
Heterozygous:-
1. It contains two different alleles for a particular trait.
2. Genotype for heterozygous possess both dominant and recessive alleles. For example, Rr
3. It produces two different kinds of gametes.
(c) Monohybrid and Dihybrid:-
Monohybrid:-
1. Monohybrid involves cross between parents, which differs in only one pair of contrasting characters.
2. For example, the cross between tall and dwarf pea plant is a monohybrid cross.
Dihybrid:-
1. Dihybrid involves cross between parents, which differs in two pairs of contrasting characters.
2. For example, the cross between pea plants having yellow wrinkled seed with those having green round seeds is a dihybrid cross.
Mendel selected pea plants to carry out his study on the inheritance of characters from parents to offspring. He selected a pea plant because of the following features. 1. Peas have many visible contrasting characters such as tall/dwarf plants, round/wrinkled seeds, green/yellow pod, purple/white flRead more
Mendel selected pea plants to carry out his study on the inheritance of characters from parents to offspring.
He selected a pea plant because of the following features.
1. Peas have many visible contrasting characters such as tall/dwarf plants, round/wrinkled seeds, green/yellow pod, purple/white flowers, etc.
2. Peas have bisexual flowers and therefore undergo self-pollination easily. Thus, pea plants produce offsprings with same traits generation after generation.
3. In pea plants, cross pollination can be easily achieved by emasculation in which the stamen of the flower is removed without affecting the pistil.
4. Pea plants have a short life span and produce many seeds in one generation.
A diploid organism is heterozygous for 4 loci, how many types of gametes can be produced?
Locus is a fixed position on a chromosome, which is occupied by a single or more genes. Heterozygous organisms contain different alleles for an allelic pair. Hence, a diploid organism, which is heterozygous at four loci, will have four different contrasting characters at four different loci. For exaRead more
Locus is a fixed position on a chromosome, which is occupied by a single or more genes. Heterozygous organisms contain different alleles for an allelic pair. Hence, a diploid organism, which is heterozygous at four loci, will have four different contrasting characters at four different loci.
For example, if an organism is heterozygous at four loci with four characters, say Aa, Bb, Cc, Dd, then during meiosis, it will segregate to form 8 separate gametes.
If the genes are not linked, then the diploid organism will produce 16 different gametes. However, if the genes are linked, the gametes will reduce their number as the genes might be linked and the linked genes will be inherited together during the process of meiosis.
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-12/biology/chapter-5/
Differentiate between the following: (a) Dominance and Recessive (b) Homozygous and Heterozygous (c) Monohybrid and Dihybrid.
(a) Dominance and Recessive:- Dominance:- 1. A dominant factor or allele expresses itself in the presence or absence of a recessive trait. 2. For example, tall plant, round seed, violet flower, etc. are dominant characters in a pea plant. Recessive:- 1. A recessive trait is able to express itself onRead more
(a) Dominance and Recessive:-
Dominance:-
1. A dominant factor or allele expresses itself in the presence or absence of a recessive trait.
2. For example, tall plant, round seed, violet flower, etc. are dominant characters in a pea plant.
Recessive:-
1. A recessive trait is able to express itself only in the absence of a dominant trait.
2. For example, dwarf plant, wrinkled seed, white flower, etc. are recessive traits in a pea plant.
(b) Homozygous and Heterozygous:-
Homozygous-
1. It contains two similar alleles for a particular trait.
2. Genotype for homozygous possess either dominant or recessive, but never both the alleles. For example, RR or rr
3. It produces only one type of gamete.
Heterozygous:-
1. It contains two different alleles for a particular trait.
2. Genotype for heterozygous possess both dominant and recessive alleles. For example, Rr
3. It produces two different kinds of gametes.
(c) Monohybrid and Dihybrid:-
Monohybrid:-
1. Monohybrid involves cross between parents, which differs in only one pair of contrasting characters.
2. For example, the cross between tall and dwarf pea plant is a monohybrid cross.
Dihybrid:-
1. Dihybrid involves cross between parents, which differs in two pairs of contrasting characters.
2. For example, the cross between pea plants having yellow wrinkled seed with those having green round seeds is a dihybrid cross.
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-12/biology/chapter-5/
Mention the advantages of selecting pea plant for experiment by Mendel.
Mendel selected pea plants to carry out his study on the inheritance of characters from parents to offspring. He selected a pea plant because of the following features. 1. Peas have many visible contrasting characters such as tall/dwarf plants, round/wrinkled seeds, green/yellow pod, purple/white flRead more
Mendel selected pea plants to carry out his study on the inheritance of characters from parents to offspring.
He selected a pea plant because of the following features.
1. Peas have many visible contrasting characters such as tall/dwarf plants, round/wrinkled seeds, green/yellow pod, purple/white flowers, etc.
2. Peas have bisexual flowers and therefore undergo self-pollination easily. Thus, pea plants produce offsprings with same traits generation after generation.
3. In pea plants, cross pollination can be easily achieved by emasculation in which the stamen of the flower is removed without affecting the pistil.
4. Pea plants have a short life span and produce many seeds in one generation.
For more answers visit to website:
See lesshttps://www.tiwariacademy.com/ncert-solutions/class-12/biology/chapter-5/