Genetics

To solve the problem, we need to identify the cause of Trichomoniasis.

1. Understanding Trichomoniasis:
Trichomoniasis is a sexually transmitted infection (STI) caused by a protozoan parasite called *Trichomonas vaginalis*. It is not caused by bacteria, fungi, or viruses.

2. Analyzing the Options:
Let's evaluate each option to determine the correct cause:

• Bacteria: Trichomoniasis is not caused by bacteria, so this option is incorrect.
• Fungus: Trichomoniasis is not caused by a fungus, so this option is also incorrect.
• Protozoan: The correct cause of Trichomoniasis is *Trichomonas vaginalis*, a protozoan parasite. This is the correct answer.
• Virus: Trichomoniasis is not caused by a virus, so this option is incorrect.

3. Conclusion:
Trichomoniasis is caused by a protozoan parasite.

Final Answer:
The correct answer is (C) Protozoan.

Step 1: Understanding Blood Group Inheritance.
The AB parent can contribute either an A or a B allele, while the AA parent can only contribute an A allele. Therefore, the possible blood groups for the children are either A (from AA or AB parent contributing an A allele) or AB (from AB parent contributing a B allele while the other parent contributes an A allele).
Step 2: Analyzing the Incorrect Options.
Given the parents' genotypes, the children cannot have blood group B or O. Blood group B would require a B allele from the AB parent and a B or O allele from the other parent, which is not possible as the other parent is homozygous A (AA). Similarly, blood group O is impossible as it would require both parents to contribute an O allele, which neither has.

Step 1: In Grasshoppers, the XX-XO type of sex determination is found. In this system, females have two X chromosomes (XX), and males have only one X chromosome (XO). The presence or absence of the second X chromosome determines the sex of the offspring.
Step 2: In Drosophila (fruit flies), the XX-XY sex determination system is used, not ZZ-ZO. In this system, females have two X chromosomes (XX), and males have one X chromosome (XY). The sex of the offspring is determined by the presence of the X and Y chromosomes.
Step 3: In Birds, the ZZ-ZW type of sex determination is found. In this system, males have two Z chromosomes (ZZ), and females have one Z and one W chromosome (ZW). The female's W chromosome determines the sex of the offspring.
Step 4: In Humans, the XX-XY type of sex determination is present. This system is similar to Drosophila in that females have two X chromosomes (XX), and males have one X and one Y chromosome (XY).
Conclusion: The incorrect pair is (2) ZZ-ZO type — Drosophila. Drosophila uses the XX-XY sex determination system.

Step 1: Holandric genes are genes that are located on the Y-chromosome. These genes are passed down from father to son, as males inherit the Y-chromosome from their fathers.
Step 2: The Y-chromosome carries genes responsible for male sex determination and spermatogenesis. These genes are responsible for traits that are exclusively inherited from father to son, and they are not found on other chromosomes, such as somatic chromosomes, X chromosomes, or chromosome 21.
Step 3: Somatic chromosomes (Option 1) are the non-sex chromosomes (autosomes) that contain most of the genes for an individual’s traits but do not carry holandric genes.
Step 4: X-chromosome (Option 2) carries many genes involved in various functions and traits, but holandric genes are not located on the X-chromosome.
Step 5: Chromosome 21 (Option 4) is one of the autosomal chromosomes and is not related to holandric genes.
Conclusion: Holandric genes are located on the Y-chromosome, making Option (3) the correct answer.

To solve this problem, we need to identify the incorrect statements regarding blood groups based on the options provided.

1. Understanding the Statements:
Let's evaluate each statement:

• Statement I: "The mother with Rh- blood group develops passive immunity on administering IgM antibodies." - This statement is incorrect. Rh- mothers are at risk of Rh incompatibility with their Rh+ fetus, and passive immunity would not be conferred through IgM antibodies. Instead, IgG antibodies are involved in Rh incompatibility, not IgM. This makes the statement incorrect.
• Statement II: "Isoagglutinogens are sugar polymers bound to fatty acids on the RBC membrane." - This statement is correct. Isoagglutinogens are specific antigens (like A and B antigens) found on the surface of red blood cells (RBCs), which are made up of sugar polymers bound to lipid molecules.
• Statement III: "The alleles for Rh factor are located on three different loci on chromosome pair 9." - This statement is incorrect. The alleles for the Rh factor (like Rh+ and Rh-) are located at a single locus on chromosome 9, not three different loci. Therefore, this statement is incorrect.
• Statement IV: "The expression of ABO blood types in man is by three alleles of a single gene." - This statement is correct. The ABO blood group system is determined by three alleles (A, B, and O) of a single gene located on chromosome 9.

2. Conclusion:
Based on the analysis, the incorrect statements are Statements I and III.

Final Answer:
The correct answer is Option C: I, III.

Evaluating each genetic condition. Klinefelter's syndrome is correctly described as 47, XXY, involving an extra X chromosome in males.
Turner's syndrome should be 45, X, not 45, XY. This syndrome is characterized by the presence of a single X chromosome and the absence of the second sex chromosome, not an XY configuration.
Down syndrome is accurately described as having an extra 21st chromosome, leading to a total of 47 chromosomes.
Edward syndrome is also correctly identified with an extra 18th chromosome, resulting in 47 chromosomes.

To solve the problem, we need to identify the correct statements regarding the Human Genome Project.

1. Analyzing the Statements:

Statement I: "The method of DNA sequencing was developed by Jeffreys." This statement is incorrect. DNA sequencing, as we know it today, was primarily developed by Frederick Sanger, not Jeffreys.

Statement II: "Identification of genes that express as RNA is referred to as Expressed Sequence Annotation." This statement is correct. The process involves identifying genes that are actively transcribed into RNA and annotating their sequences.

Statement III: "About 1.4 million locations where single base DNA differences occur in humans." This statement is correct. The Human Genome Project identified many single nucleotide polymorphisms (SNPs) that occur across human genomes.

Statement IV: "Y-chromosome has 231 genes." This statement is correct. The Y-chromosome is known to contain around 231 functional genes.

2. Analyzing the Correct Combination:
The correct statements are III and IV.

Final Answer:
The correct option is (C) III, IV.