If you were to sample garden pea plants in Mendel’s garden, which of the following statements would hold?
Round seeds were more abundant than wrinkled seeds.
Wrinkled seeds were more abundant than round seeds.
Both round and wrinkled seeds were equally abundant.
Answer depends on the time of day when sampling is done.
(1)
Dominant allele can express even in the presence of a recessive allele. Hence dominant phenotype is more common. Round seeds are dominant over wrinkled seeds; hence would be more abundant.
In peas, a pure tall (TT) is crossed with a pure short plant (tt). The ratio of pure tall plants to pure short plants in generation is:
1:3
3:1
1:1
2:1
(3)
In the generation, the ratio of pure tall plants to pure short plants will be 1:1. The other two plants that are produced will be tall as well, but will not be pure.
Two pea plants one with round green seeds (RRyy) and another with wrinkled yellow (rrYY) seeds produce progeny that have round yellow (RrYy) seeds. When plants are self-pollinated, the progeny will have a new combination of characters. Choose the new combinations from the following:
(i) Round, yellow
(ii) Round, green
(iii) Wrinkled, yellow
(iv) Wrinkled, green
(i) and (ii)
(i) and (iv)
(ii) and (iii)
(i) and (iii)
(2)
The new combination in progeny will be round yellow and wrinkled green. The phenotypic ratio obtained in a dihybrid cross is 9:3:3:1.
The phenotypic ratio will be – Round Yellow: Round green: Wrinkled yellow: Wrinkled green = 9:3:3:1
In humans, the sex Chromosomes comprises one pair of the total of 23 pairs of chromosomes. The other 22 pairs of chromosome are called:
Autosomes
Chromosomes
Meiosis
All of these
(1)
In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Twenty-two of these pairs, called autosomes, look the same in both males and females. The 23rd pair, the sex chromosomes, differ between males and females. Females have two copies of the X chromosome, while males have one X and one Y chromosome.
The number of pairs of sex chromosomes in the zygote of humans is:
1
2
3
4
(1)
In the human zygote, the number of pairs of autosomes and sex chromosomes is the same as in an adult human. A human adult possesses 23 pairs of chromosomes, 22 of which are autosomes and 1 of which is a sex chromosome.
In human males all the chromosomes are paired perfectly except one. These unpaired chromosomes are:
(i) Large chromosome
(ii) Small chromosome
(iii) Y-chromosome
(iv) X-chromosome
(i), (ii)
(iii) only
(iii), (iv)
(ii), (iv)
(3)
In human males, one pair called as the sex chromosomes are unpaired. Here, one is a normal sized X chromosome while the other is a short Y chromosome. Women have a perfect pair of sex chromosomes, both called as X. Whereas in males the X and Y chromosomes are not paired well.
Which chromosomes do not play any role in the determination of the sex of an individual?
Autosomes
Metacentric chromosomes
Acrocentric chromosomes
None of the above
(1)
Autosomes do not play any role in the determination of the sex of an individual since they are alike in both the males and the females and are 22 in pairs.
The two versions of a trait which are brought in by the male and female gametes are situated on:
Copies of the same chromosome
Two different chromosomes
Sex chromosomes
Any chromosomes
(1)
On different copies of the same chromosome, different alleles are present. One chromosome is inherited from the father via the male gamete, while the other chromosome is inherited from the mother via the female gamete. After fertilisation, a zygote with 23 pairs of chromosomes is created, with alleles for a trait present on the homologous pair.
Humans have two different sex chromosomes, X and Y. Based on Mendel’s laws, a male offspring will inherit which combination of chromosomes?
Both the X chromosomes from one of its parents
Both the Y chromosomes from one of its parents
Combination of X chromosomes from either of its parents
Combination of X and Y chromosome from either of its parents
(4)
The X and Y chromosomes are found in humans and most other mammals. Males have both X and Y chromosomes in their cells, whereas females have two X chromosomes. X chromosomes are found in all egg cells, while X or Y chromosomes are found in sperm cells.
Which of the following can be inherited from parents to offspring?
Swimming technique
Big nose
Sculpted body
All of the above
(2)
Big nose is an inherited trait which can be passed from parents to offspring.
