Major organs begin to develop during which part of human gestation?
fertilization
first trimester
second trimester
third trimester

first trimester

Explanation:

During the first trimester, the baby's major organs begin to develop. This happens specifically in the second month of pregnancy.

The second month of pregnancy (first trimester) is especially critical for the baby's development. Any problem with drugs, viruses, or environmental factors such as pesticides can cause birth defects.

Baby's development is very rapid during the second month and by the end of this month, all major organ and systems including brain, lungs, liver, and stomach will have begun to develop. The first bone cells appear. The eyelids form and grow, but are closed immediately and the ears are formed. The ankles, big toe, wrists, toes, and sexual organ develop.

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.

straight or amphibians are homeothermic to thermal