Ch. 1 Biology in the 21st Century

At which stage of scientific thinking are scientists most likely to consider the data and conclusions of other scientists to propose new experiments?

• observing

• testing hypotheses

• analyzing data

• forming hypotheses

A physical environment with different species that interact with one another and with nonliving things is called a(n)

• biosphere

• ecosystem

• habitat

• adaptation

The various parts of Earth's biosphere are connected and

• similar

• nonliving

• diverse

• aquatic

During an experiment, which factors are observed and measured?

• dependent variables

• independent variables

• constants

• hypotheses

The study and manipulation of DNA on a molecular level is known as

• biochemistry

• genomes

• molecular genetics

• evolution

What is the name given for genetic changes in living things over time?

• adaptation

• homeostasis

• evolution

• negative feedback

Scientists use observations and data to form and test

• constants

• hypotheses

• theories

• conclusions

Similar organisms that can reproduce by interbreeding belong to the same

• ecosystem

• environment

• habitat

• species

How have computer models expanded biological research?

• they help scientists design better experiments

• they simulate complex biological systems that cannot be studied directly

• they give scientists the ability to observe molecules directly

• they allow the use of human experimental subjects

Which phrase best describes scientific theories?

• explain few observations

• serve as speculations

• are never proven

• cannot be replaced