Question 26

certain types of atoms break down at a known rate. scientists can measure the amounts of the broken down products present in a sample to calculate its age. what is this technique called?

natural selection

the fossil record

speciation

radiometric dating
2 points
question 27

during which era did plants first appear on land?

cenozoic

mesozoic

paleozoic

precambrian
2 points
question 28

how were multicellular organisms developed on early earth?

eukaryotes began grouping together to develop multicellular organisms

cyanobacteria released oxygen molecules into the air creating new multicellular organisms

prokaryotes combined to form new multicellular organisms

prokaryotes combined with cyanobacteria to develop multicellular organisms

Sand spinifex grass is adapted to growing on sand dunes. it is a rapidly spreading plant and the creeping runners produce new root systems. which of these best explains the benefits of these features? a. it limits water loss through the leaves. b. it provides support by anchoring the plant. c. it protects the plant from predators. d. it allows the plant to tolerate salt. reset submit

The influenza virus cause the flu, but not other diseases. why?

Briefly describe the scenario that was discussed in the behaving brain that demonstrated that the brain can change based on state or mood. which disease could the research involving rats and learning experiments that was discussed in the behaving brain ultimately with? in the behaving brain, what is a common misunderstanding about amnesia that was mentioned? what is the truth about amnesia that's mentioned? what does research discussed in the responsive brain show to be different in men and women's reaction to touch? what was discussed in the responsive brain as being brain-based and a vital part of normal growth and development in young children? in the responsive brain, what do they discuss as a possibility for leading to deficiencies in cognitive impairment as we age? in the responsive brain, what did the research involving african cichlid fish demonstrate? briefly describe the back story and affliction of the author of peter pan. what did you find most interesting about the behaving brain video, and why? what did you find most interesting about the responsive brain video, and w