Which best describe fetus development? a.) the heart beats and is heard during the first trimester. b.) the heart beats and is heard during the second trimester. c.) the heart beats during the first trimester, but is heard in the second trimester. d.) the heart beats during the second trimester, and is heard in the third trimester.

The correct answer is:

A fetal heartbeat may prime be identified by a vaginal ultrasound as new as 5 1/2 to 6 weeks following gestation. That’s during a fetal pole, the first obvious sign of a developing embryo, can seldom be observed.

explanation:

the fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus eohippus.

flooding wildfire landslides climate change the factors listed have an immediate effect on the animal populations found in any habitat. the four factors would lead to a death. b emigration. eliminate c immigration. d mutations.