Day 134: CBSE Class 10 Science

5 questions (8 parts). Try each one first, then open its answer.

Question 1
Electricity. Asked once: 2025 (same type asked 3 times)
25 (b) $2\,\Omega$
Question 2 (case study, 4 parts)
Heredity. Asked once: 2023 (same type asked 3 times)
All human chromosomes are not paired. Most human chromosomes have a maternal and a paternal copy, and we have 22 such pairs. But one pair called the sex chromosomes, is odd in not always being a perfect pair. Women have a perfect pair of sex chromosomes. But men have a mismatched pair in which one is normal sized while the other is a short one.
38 (a) $In humans, how many chromosomes are present in a Zygote and in each gamete ?$
38 (b) $A few reptiles rely entirely on environmental cues for sex determination. Comment.$
38 (c) $“The sex of a child is a matter of chance and none of the parents are considered to be responsible for it.” Justify it through flow chart only.$
38 (c) OR $Why do all the gametes formed in human females have an X chromosome ?$
Question 3
How do Organisms Reproduce?. Asked once: 2024 (same type asked 3 times)
30 $Explain the events that take place once a sperm reaches the oviduct till it becomes a foetus. Write the role of placenta in pregnancy.$
Question 4
Life Processes. Asked once: 2023 (same type asked 3 times)
23 $Give the name of the enzyme present in the fluid in our mouth cavity. State the gland which produces it. What would happen to the digestion process if this gland stops secreting this enzyme ?$
Question 5
Light — Reflection and Refraction. Asked once: 2024 (same type asked 3 times)
25 $Define power of a lens. Find power of a lens whose focal length is 50 cm.$

Question 1

Question 2 (case study, 4 parts)

Question 3

Question 4

Question 5