Human Health and Diseases — BIOLOGY STD 12 Science — Question

Normally one embryo develops in one seed but when an orange seed is squeezed many embryos of different shapes and sizes are seen. Mention how it has happened.

Differentiate between immigration and emigration.

Construct a grazing food chain and a detritus food chain using the following, with five links in each:
Earthworm, bird, snake, vulture, grass, grasshopper, frog, decaying plant matter.

Name four micronutrients whose deficiencies affect the health of the people.

What are the events taking place in the ovary and uterus during follicular phase of the menstrual cycle?

Mention the factors that regulate the rate of function of the entire pond.

The doctor could hear the heartbeats in a foetus. How many days of gestation period must have passed?

The cell division involved in gamete formation is not of the same type in different organisms. Justify.

How is evaluation and testing of the new variety carried out?

Describe the role of lymph nodes in providing immunity.