The ventricles have thick muscular walls whereas the auricles have thin walls. Why do you think thick muscular walls are necessary in the ventricles and not in the auricles?
Important Questions on Transportation of Materials in Plants and Animals
A researcher in Chennai wants to study how much carbohydrate is burnt up in the body in a long-distance race. She measured the body weights of athletes before and after a 2 km race. She found to her surprise that each athlete lost 1 kg or more. The athletes could not have burnt 1 kg carbohydrates in their bodies in a 2 km race, she thought.
Answer these questions.
What do you think the reduction in body weight was due to?
A researcher in Chennai wants to study how much carbohydrate is burnt up in the body in a long-distance race. She measured the body weights of athletes before and after a 2 km race. She found to her surprise that each athlete lost 1 kg or more. The athletes could not have burnt 1 kg carbohydrates in their bodies in a 2 km race, she thought.
Do you think she had designed the experiment properly?
Complete the following table showing safe and unsafe donors for each blood group.
| BLOOD GROUP OF RECEIVER | SAFE DONORS | UNSAFE DONORS |
| A | A and O | B and AB |
| B | B and O | A and AB |
| AB |
