Zoology: Solved Previous Year Question Paper for NCERT/ CBSE  Class 12th Zoology Paper code (HSEIIRKO– 13) 

 (Long Answer Type Questions) 

Question: Define Spermatogenesis.With the help of a graphic sketch explain the processes involved in spermatogenesis. 

Ans: The process by which sperm cells are produced in male testes from spermatogonial stem cells is known as spermatogenesis. For mature sperm to be produced, this process necessitates several intricate processes, including mitosis, meiosis, and differentiation.

The graphic sketch of spermatogenesis is shown below:

1. In the seminiferous tubules of the testes, stem cells divide to create two daughter cells during mitosis, and these daughter cells eventually develop into spermatogonia.

2. The primary spermatocytes go through meiosis I and divide to form two haploid secondary spermatocytes.

3. The second meiosis, which produces four haploid spermatids, occurs on the secondary spermatocytes.

4. The spermatids then go through spermiogenesis, which is a process of differentiation in which they lose their cytoplasm and grow flagella to form mature sperm.

5. The fully developed sperm are now free to fertilise an egg and are released into the epididymis tube.                                

Question: What are Chromosomal Disorders? How can you differentiate Klinefelter Syndrome and Turner Syndrome?

Ans: A change in the structure or quantity of chromosomes can result in chromosomal diseases. The genetic code for a living thing is stored in chromosomes, which are large strands of DNA. Disabilities of the body and mind can result from changes in the number or structure of chromosomes. Chromosome diseases like Down syndrome, Klinefelter syndrome, Turner syndrome, and Cri-du-chat syndrome are examples.

A second copy of the X chromosome is the cause of the genetic condition Klinefelter Syndrome, which affects boys. Small testes, a tall build, and potential learning issues are its defining traits. A missing or partial X chromosome is the only genetic condition that causes Turner Syndrome, which only affects females. It can result in infertility and is distinguished by its small stature and webbed neck.

Question: Describe in brief the evolution of Man.

Ans: Around 7 million years ago, chimpanzees, bonobos, and humans all descended from a single common ancestor. Over the following several million years, early hominids (or “human-like” species”) developed in Africa and started to disperse outside of the continent. Around 1.9 million years ago, Homo erectus appeared, and 800,000 years ago, Homo sapiens appeared. Homo sapiens started moving out of Africa and into other parts of the world about 200,000 years ago. With a roughly 200,000-year history, modern Homo sapiens have achieved significant strides in technology, culture, and communication. (Short Answer Type Questions) 

Question: Write a brief note on Amniocentesis. 

Ans: A medical procedure called amniocentesis is performed to identify genetic abnormalities in the foetuses. It entails putting a needle into the amniotic sac of a pregnant woman and removing part of the amniotic fluid. The fluid, which contains foetal cells, is examined for chromosomal flaws or genetic diseases. Amniocentesis is normally carried out between 15 and 20 weeks of gestation but may be done at any time beyond that. The chance of miscarriage is very low and the operation is regarded as being extremely safe.

Question: What is DNA Finger Printing? Write down its uses. 

Ans: Forensic scientists use the process of DNA fingerprinting to locate a person using their distinctive DNA profile. It entails separating and examining a person’s DNA from a sample of cells taken from bodily fluids, hair, or other tissue. DNA fingerprinting can be used to establish a person’s identification, prove a person’s biological connections to other people, and find out if a person has a genetic condition. Additionally, it can be utilised to crack open cold cases and apprehend perpetrators. It is also applied to paternity investigations and the identification of disaster or mass grave victims.

Question: Write down the symptoms of Malaria. 

Ans: 1. High fever 2. Chills 3. Sweating 4. Headaches 5. Vomiting 6. Nausea 7. Muscle aches 8. Fatigue 9. Anaemia 10. Diarrhoea 11. Cough 12. Loss of appetite 13. Jaundice 14. Blood in urine 15. Seizures

Question: What do you mean by Parturition? 

Ans: The process of childbirth, when a baby is delivered from the mother’s uterus, is known medically as parturition.

Question: What do you understand by Alcohol abuse?

Ans: Alcohol abuse is the excessive use of alcoholic beverages to the point where it affects relationships, jobs, school, physical and mental health, or other facets of daily life. Additionally, dangerous actions like drinking and driving can be taken while under the influence of alcohol. Abusing alcohol over an extended period can result in physical, emotional, and even addictive dependence.

Question: What are Biosafety issues? 

Ans: The steps taken to assure the safe use, handling, and disposal of biological materials are referred to as biosafety issues. These concerns include the safe handling of genetically modified organisms, the containment of potentially infectious agents in laboratory settings, and adequate biological waste disposal. It also entails safeguarding the environment, lab workers, and other people from potentially dangerous chemicals.

 Objective Type Questions/M.C.Q. 

(i) Treponema pallidium is a : 

(a) Bacterial agent 

(b) Viral agent 

(C) Protozoal agent 

(d) Fungal agent (Choose the correct

Answer: (a) Bacterial agent 

Question: (ii) Expand the term PKU. 

Ans: Phenylketonuria (PKU)

Question:  (iii) Ramapithecus was the link between man and other primates. 

 (Say yes/no)

Ans: Yes

Question: (iv) The process by which a person overcomes drinking is known as ……

Ans: Alcohol recovery or sobriety.

Question: (v) Those who specialize in viruses and deal with how they infect are 


(Whether True/False) 

Ans: False

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