Test: Genetics - 2 - Class 10 MCQ

Each dihybrid plant produces 4 gamete types of equal frequency. In the offspring F2 showed 4 different phenotypes : the round and yellow traits did not stay linked to each other. 

Explanation:

• Most likely explanation for tallness being more widespread among pea plants is that tallness is dominant over dwarfness.
• This means that even if a pea plant inherits the dwarf allele from one parent, it can still exhibit the tall phenotype if it inherits the tall allele from the other parent.

Explanation:

• The fact that all plants in the F1 generation were red confirms that the white color is a recessive character.
• This means that for a plant to have a white color, it must have two copies of the recessive allele (rr).
• Therefore, the correct answer is A: Recessive character.

Explanation:

• Here are the possible combinations of genes for their first child:
• The child can inherit the straight hair gene from both parents (SS). In this case, the child will have straight hair.
• The child can inherit the straight hair gene from the mother and the curly hair gene from the father (SC). In this case, the child will have straight hair, as the dominant straight hair gene overrides the recessive curly hair gene.
• The child can inherit the curly hair gene from both parents (CC). In this case, the child will have curly hair.
• Therefore, out of the three possible combinations of genes, two result in the child having straight hair and one results in the child having curly hair.

Conclusion:
The chance that their first child will have curly hair is one in two (1/2) or 50%.

In conclusion, Mendel's success in discovering the principles of inheritance can be attributed to his systematic approach, the traits he chose to study, the absence of genetic linkage, and the use of pure-breeding plants. These factors allowed him to make accurate observations, establish patterns of inheritance, and formulate the fundamental laws of genetics.

Explanation:

• Mendel's interest and passion for studying pea plants played a crucial role in his success.
• Pea plants possess several advantages for genetic research, such as their short generation time, large number of offspring, and easily observable traits.
• Mendel's fondness for pea plants motivated him to conduct numerous experiments and meticulously analyze the results, leading to his groundbreaking discoveries in genetics.
• Therefore, among the given options, the factor that most significantly contributed to Mendel's success was his decision to consider only one character at a time (option D).

The genotype of an organism is the chemical composition of its DNA, which gives rise to the phenotype, or observable traits of an organism. A genotype consists of all the nucleic acids present in a DNA molecule that code for a particular trait

Diploid organisms, for example, humans, have paired homologous chromosomes in their somatic cells, and these contain two copies of each gene.

An organism in which the two copies of the gene are identical — that is, have the same allele — is called homozygous for that gene.

When an individual is having both the alleles of a contrasting character, it is said to be HETEROZYGOUS .

In F2 -3 tall : 1 dwarf This is the law of segregation. 1 Homozygous tall 1 Homozygous dwarf 2 Heterozygous tall.

All red flowered plants; according to Mendel's law of dominance. 

Almost everyone has around a 50% chance of having a boy and a 50% chance of having a girl. What we can say is that dad's sperm determines whether a baby will be a boy or a girl. About half of his sperm will make a boy and half a girl. The sex of the baby depends on which sperm gets to the egg first.

The human sex chromosomes are a typical pair of allosomes. These chromosomes determine the sex of an individual when reproducing. Allosomes are also referred to as sex chromosomes or idiosomes

The Barr body, also sometimes called the sex chromatin, is the inactive X chromosome in female somatic cells. Human females have two X chromosomes, while males have one X and one Y. In all of the female somatic cells, which don’t take part in sexual reproduction, one of the X chromosomes is active.