Q1. A particular pea plant produces only violet flowers.
(a) Is it homozygous for the trait or heterozygous?
(b) How would you ensure its genotype? Explain with the help of crosses?
Q2. Give reasons for the following:
(a) What will be the effect on the rate of photosynthesis in both C3 and C4 plants if the concentration of carbon dioxide is continuously increased?
(b) Can photosynthesis occur under high pressure sodium lights?
(c) Why photorespiration is considered to be wasteful process for plants?
Q3. (a) What complications arise at the replicating fork because of DNA- dependant DNA polymerase catalyzed polymerization?
(b) How is this complication resolved?
Q4. (a) Plant hybridization procedures often result in introduction of undesirable genes along with desirable ones. How can this problem be overcome?
(b) How is the PCR technology helpful in the early diagnosis of diseases?
Q5. A man of B - blood group marries a woman of AB blood group. Which type of progeny would indicate that the man is heterozygous?
Q6. How do catalytic converters, used in vehicles, help in reducing the pollution levels? State a precaution which needs to be observed while using catalytic converters.
Q7. (a) How does frameshift mutation prove that our genetic code is triplet?
(b) During transcription, both strands of DNA are not copied. Why?
Q8. How does aneuploidy results in the occurrence of chromosomal disorders?
Explain with the help of examples.
Q9. (a) ATGGTAATCTAA
The given sequence represents a piece of DNA that constitutes a functional gene before a certain mutation. After mutation the changed sequence is as follows.
ATGGGTAATCTAA
The mutation caused the formation of a new polypeptide
(i) Name the type of mutation that has occurred is the sequence.
(ii) Name a disease that is caused by the occurrence of a similar kind of mutation.(b) In tomato plants, the gene for purple stem (P) is dominant over the gene for green stem (p) and the gene for red fruits (R) is dominant over the gene for yellow fruits (r). If two plants heterozygous for both the traits are crossed, what proportion of the offspring are expected to have
(i) Green stem and yellow fruits
(ii) Purple stem with yellow fruits
(iii) Green stem and red fruits
(iv) Purple stem and red fruits
Q10. If a drop of each of the following alternatives is placed at the four corners of a slide. Which one of the following cannot be expected to coagulate?
A. Blood from pulmonary vein B. Blood from aorta
C. Blood plasma D. Blood serum
Q11. What is the value of RQ when palmitic acid (C16H32O2 ) is converted into sucrose, carbon dioxide and water in the presence of oxygen in the endosperm tissue of germinating seeds?
A. 0.36 B. 0.69
C. 0.70 D. 0.90
Q12. Which of the following events is not observed during the depolarisation of the nerve fibre?
A. The potassium ions leave the fibre at a faster rate than sodium ions
B. The permeability of the membrane toward sodium ions increases
C. The sodium ions move inside the membrane
D. The nerve fibre becomes positively charged
Q13. Which of the following in vitro assisted reproductive technology should be recommended by a doctor to a female who cannot produce ovum but can provide suitable environment for fertilization and development of embryo?
A. ZIFT B. GIFT
C. ICSI D. IUT
Q14. In a population of 1000 individuals, 360 belong to genotype AA, 480 to Aa and the remaining 160 to aa. Based on this data, the frequency of allele A in the population is:
A. 0.4 B. 0.5
C. 0.6 D. 0.7
Q15. Lesch-Nyhan syndrome is an x- linked recessive disorder that cause neurological damage in human beings. A survey of 500 males from a population revealed that 20 were effected with this disorder. What is the frequancy of the normal allele in the population?
A. 9.6 B. 0.8
C. 0.096 D. 96