IGCSE Biology Paper-5: Specimen Questions with Answers 29 - 31 of 62
Question 29
Describe in Detail Subjective▾
Starch is a type of carbohydrate present in many of our food Items. Carbohydrates are energy-yielding components of food.
Here three types of food material are given. Identify the presence of carbohydrate
EditExplanation
- To identify the presence of carbohydrate in food material first place the all materials in separate and clean petri plate.
- Drop out iodine solution to each item (2 - 3 drops) .
- When we observe all three petri plates
- Blue-black colour appears on bread slice and potato slice, whereas, chickpea seeds do not show any change in colour.
- It shows Bread and potato contain starch which gives blue-black in color on addition of iodine solution.
- Chickpea seeds do not contain starch and thus do not show any change in color.
Passage
An infestation of body lice occurs when a certain type of lice invade the body and clothing. Lice are parasitic organism that feed on human blood and can infest the head, body, and pubic area.
Question 30 (1 of 3 Based on Passage)
Explanation
- intense itching (pruritus)
- allergic reaction to body
- red bumps on the skin
- thickened or darkened skin mainly near the waist , if the lice have been there for a long time
Question 31 (2 of 3 Based on Passage)
Write in Short Short Answer▾
Name the class of arthropods to which this animal belongs with reason.
EditExplanation
Human lice fall under the phylum Arthropod because of the following features:
- Triploblastic embryo, which means embryos, have three different types of tissues, the endoderm, mesoderm and ectoderm
- Segmented bodies.
- Exoskeleton composed of chitin, providing support and protection.
It belongs from the class Insect