4x 5 = 20
Q3. Answer the following questions:-
1. what are STDs. With examples
2. What are the major steps involved in photosynthesis.
3. Difference between concave and convex lens
4. Draw images formd by convex lenses
5. What are the differences between law of refrection and reflection.
5 x 4 = 20
Q4. Answer the following questions:-
1.. What are the limitations of Law of octave.
2. Draw and lebel the female reproductive system.
3. Expalin the structure of nephron with diagram.
4. Contraceptive method, explain
Answers
Answer:
1) Sexually transmitted diseases (STDs) are infections transmitted from an infected person to an uninfected person through sexual contact. STDs can be caused by bacteria, viruses, or parasites. Examples include gonorrhea, genital herpes, human papillomavirus infection, HIV/AIDS, chlamydia, and syphilis.
2)It is convenient to divide the photosynthetic process in plants into four stages, each occurring in a defined area of the chloroplast: (1) absorption of light, (2) electron transport leading to the reduction of NADP+ to NADPH, (3) generation of ATP, and (4) conversion of CO2 into carbohydrates (carbon fixation).
3)A convex lens is thicker at the centre and thinner at the edges. A concave lens is thicker at the edges and thinner at the centre. Due to the converging rays, it is called a converging lens. Due to the diverging rays, it is called a diverging lens.
5)Reflection is the bouncing back of light when it strikes a smooth surface. Refraction is the bending of light rays when it travels from one medium to another. Generally occurs on shinny surfaces that only allow rebounding of light without permitting penetration through it.