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- How many chromosomes are present in male and female grasshopper?
Ans: The numbers of chromosomes in male are 23. It has 11 pairs and one X chromosome. So, it is XO. The female has 24 chromosomes. It has 12 pairs of autosomes and one pair of sex chromosome XX.
- What is difference between homogametic and heterogametic animals?
Ans: The gametes which produce only type of gametes are called homogametic. They produce gametes all having X chromosome. The animals which produce two types of gametes i.e. X and Y are called heterogametic. Sex Linked Inheritance Test Questions
- What is XO-XX type of sex determination? In which animals is it found?
Ans: The animals in which male is XO with single X chromosome and female is XX with two X chromosomes show XO-XX type sex determination, for example grasshopper and Protenor bug.
- What are nullo gametes?
Ans: A gamete without any sex chromosome is called nullo gamete.
- Who does determine sex in grasshopper?
Ans: Sex of the offspring depends on the kind of sperm that fertilizes the egg. If an X-carrying sperm fertilizes the egg, an XX female offspring is produced. If the nullo sperm fertilizes the egg, an XO male offspring is produced.
- What is XY-XX type of sex determination? In which animals is it found?
Ans: The animals in which male is XY with single XY chromosomes and female is XX with two X chromosomes show XY-XX type sex determination, for example man and drosophila.
- Who does determine sex in man?
Ans: The type of sperm determines sex of the offspring. If an X carrying sperm fertilizes the egg, the zygote will be XX. Thus, a female offspring is produced. If a Y— carrying sperm fertilizes the egg. the zygote will be XY. Sex Linked Inheritance Test Questions
- What is ZZ – WZ type of sex determination? In which animals is it found?
Ans: The animals in which male is ZZ with single two X chromosomes and female is ZW with XY chromosomes show ZZ-WZ type sex determination. It is found in birds and moths.
- Who does determine sex in birds?
Ans: In bird’s kind of egg determines the sex of the offspring. When an X — carrying egg is fertilized by the sperm, a male offspring is produced. When a Y — carrying egg is fertilized by the sperm a female offspring is produced.
- What is compound sex?
Ans: Some species maintain different kinds of many X or Y or both XY chromosomes. These chromosomes act together as a single sex-determining group. It is compound sex determination.
- What does happen if Y chromosome is missing in man and drosophila?
Ans: In man, Y chromosome has SRY genes. It absence produces female. In drosophila, missing of Y chromosome does not create any problem. The male without Y remains male in drosophila.
- What is basic difference of sex determination in man and drosophila?
Ans: The Y chromosomes of man have SRY gene. Male can be produced with these genes. The autosomes do not play any role in sex determination. Drosophila has an X chromosome—autosome balance system.
- What are dioecious plants? Give examples?
Ans: The plants in which male and female reproductive parts present on separate plant are called dioecious species like Ginkgo are dioecious. Sex Linked Inheritance Test Questions
- What was peculiarity of the F2 cross of T.H. Morgan on drosophila?
Ans: There was peculiarity result of F2 of cross of T.H. Morgan on drosophila?
- What were the hypothesis of T.H. Morgan about strange results of drosophila eye color in F2?
Ans: The gene for eye color is located on X chromosome. The alleles for eye color are present only on X chromosome. There is no corresponding allele for this trait on Y chromosome. Sex Linked Inheritance Test Questions
- What is reciprocal cross?
Ans: A cross in which the sexes of the organisms are reversed as compared to original cross is called reciprocal cross.
- What type of specific pattern is followed by sex linked inheritance?
Ans: These specific patterns are: A son inherits his X chromosome only from his mother. A daughter gets an X chromosome from each parent. An X – linked trait passes in a crisscross fashion. A son inherits only Y chromosome from father.
- What is the significance of discovery of sex linkage by T.H. Morgan?
Ans: Morgan’s discovery of sex-linked inheritance has a great importance. It greatly helped in the understanding of genes and chromosome. T.H. Morgan was awarded a Nobel Prize for this discovery.
- What are Y-linked genes? Give example?
Ans: The genes present on the Y chromosomes are called Y- linked genes and their traits are called Y-linked traits. Its example is SRY gene.
- What are opsins? What is their function?
Ans: Each type of cone cell has specific light absorbing proteins called opsins.
- What is dichromate?
Ans: A dichromatic can perceive two primary colors. But it is unable to see the third color. The opsins of this color are missing due to mutations.
- What types of mutations are present in dichromate vision?
Ans: There can be three of in it: protanopia is a red blindness. Deuteranopia is green blindness. Tritanopia is blue blindness.
- Why do some people detect altered relative shades of red and green? Give their types?
Ans: Some people see altered relative shades of these colors. They have abnormal opsins. But these opsins are still partially functional. Such people are: protanomalous for red color. Deuteranomalous for green color. Sex Linked Inheritance Test Questions
- What is monochromacy?
Ans: A monochromat can perceive only one color. Monochromacy is true color-blindness.
- Give the genetic basis of true color blindness?
Ans: Blue cone monochromacy is an X – linked recessive trait. In this case, both red and green cone cells are absent. Therefore, it is also called red – green color-blindness. It also forms zigzag pattern like other sex linked recessive trait.