March 3, 2015

238 TExES Life Science 7 – 12 Exam

The TExES Life Science 7 – 12 Exam is a certification examination that is designed to determine if an individual has the knowledge necessary to teach biology at the high school level within the Texas public school system. This exam covers some of the areas that are covered by the TExES Science 7 – 12 Exam, but the Life Science 7 -12 Exam covers these topics in more detail as it only focuses on an individual’s knowledge of topics related specifically to biology and to the teaching methods necessary to effectively teach biology at the high school level. This exam may be required, in addition to or instead of the Science 7 – 12 Exam, in order to become a certified high school biology teacher, in the state of Texas depending on the exact type of teaching position the individual is pursuing. The exam consists of 100 multiple-choice questions that are related to the following areas:

  • Scientific Inquiry and Processes (15%)
  • Cell Structure and Processes (20%)
  • Heredity and Evolution of Life (20%)
  • Diversity of Life (20%)
  • Interdependence of Life and Environmental Systems (15%)
  • Science Learning, Instruction and Assessment (10%)

The exam-taker will have five hours to complete the exam and the exam will be scored on a scale of 100 – 300 with 240 set as the minimum score considered as passing for the exam. The registration fee for the Life Science 7 – 12 Exam is $131 and the exam is administered in a computer-based format. However, there are usually other exams and fees that are required in addition to this exam in order to become certified as an entry-level high school biology teacher within the state of Texas.

238 TExES Life Science 7 – 12 Exam Practice Questions

Sample Study Notes

1. Define the term science.

The American Heritage College Dictionary defines science as “the observation, identification, description, experimental investigation and theoretical explanation of phenomena.” Its Latin root is scientia, which means “knowledge.”

  • NATURAL SCIENCE is concerned with the natural world; SOCIAL SCIENCE studies human behavior. Both are based on empirical evidence, which is observable data that can be verified by other scientists who are working in similar situations under the same conditions.
  • FORMAL SCIENCE is the systematic study of a specific area; it is essential to developing the hypotheses, theories and laws used in other scientific disciplines, i.e. describing how things work (natural science), how people think, and why they do what they do individually and as a society (social sciences). It is based on a priori evidence, which proceeds from a theory or assumption rather than from observable phenomena.
  • APPLIED SCIENCE is using scientific research in any of the natural, social and formal sciences to address human needs.

2. Discuss life science.

Life science (or biology) is the study of living organisms: their structure, function, growth, origin, evolution and distribution. The word biology is Greek: bio means “life”; logos means “speech”; biology literally means, “discussion about life.” It became a separate science in the late nineteenth century, when researchers discovered that all organisms shared basic traits. Biology studies how living things began, divides them into species, and describes what they do and how they relate to each other and the rest of the natural world. There are four unifying principles in biology: cell theory, evolution, genetics, and homeostasis. The disciplines in the life sciences are grouped by the organisms they study: botany studies plants; zoology studies animals; and microbiology studies microorganisms. These groups are further divided into smaller, specialized categories based on the level at which they are studied and the methods used to study them; for example, biochemistry studies the chemistry of life while ecology studies how organisms interrelate in the natural world. Applied fields of the life sciences, such as medicine and genetic research, combine multiple specialized categories.

3. Define scientific method, scientific inquiry, deductive and inductive reasoning.


  • SCIENTIFIC METHOD: a set of procedures used to study natural phenomena. It provides guidelines with which to pose questions, analyze data and reach conclusions. It is used to investigate an event, gain knowledge or correct earlier conclusions about the occurrence and integrate the new information with previously learned data. Researchers pose hypotheses, and design experiments and studies to test them. The process must be objective, documented and shared with other researchers so the results can be verified by replicating the study in similar situations under the same conditions.
  • SCIENTIFIC INQUIRY: used to explore theories and develop explanations for natural phenomena. It has two functions: to provide a description of how something happens and to explain why the process succeeds or fails.
  • DEDUCTIVE REASONING: a process in which a specific conclusion logically follows from a general premise. If the premise is true, the conclusion is true. Deductive reasoning is used in mathematics.
  • INDUCTIVE REASONING: a process in which a universal conclusion is formed from considering an individual example. Inductive reasoning is the methodology of the natural and social sciences.

4. Describe the steps used in the scientific method.

The steps of the scientific method described here are not necessarily used in exactly the same way in all sciences. Sometimes they happen at the same time or in a different order and may be repeated during the course of the study. Whatever order researchers use, the steps should be applied with intelligence, imagination and creativity. The following sequence is the one used most of the time.
1. A question is asked about a natural phenomenon. It should be stated in specific language to focus the inquiry.
2. The subject is thoroughly researched. Previous test results are studied. It is important to understand what the earlier experiment(s) proved or disproved.
3. With information gleaned from researching the topic, a hypothesis is formed about a cause or effect of the event, or its relationship to other occurrences.
4. An experiment is designed and conducted to test the hypothesis and gather information.
5. The resulting data is analyzed to determine if they support or refute the hypothesis.
It is common for test results to lead to more questions about the subject or a related phenomenon.

5. Define the unifying principles of biology: cell theory, evolution, gene theory, and homeostasis.


  • CELL THEORY: the cell is the basic building block of all living things; it is the smallest unit of life able to function on its own, e.g. bacteria and protozoa. In higher organisms, groups of cells form the organs and tissues. There are two kinds of cells: prokaryotic, which are present only in bacteria; and eukaryotic, which are found in all other life forms. New cells form by dividing from existing cells.
  • EVOLUTION: as a result of natural selection and changes in the gene pool (genetic drift), inherited traits morph from one generation to the next.
  • GENE THEORY: the traits of all living organisms are encoded in their DNA, the chromosome component that carries genetic information. These traits are passed from generation to generation. The physical or biochemical characteristics are capable of adapting to changes in the environment, but the only way these adaptations can be transferred to the genes is through evolution (see above).
  • HOMEOSTASIS: a self-regulating, physiological process that keeps biological systems stable and in proper balance internally, no matter what is happening in the external environment.

6. Explain heredity and its effects on the evolution of life.

Heredity is the transfer of traits and characteristics via DNA (the chromosome component that carries genetic information) from the parent to the offspring. It is seen in all life forms, from the simplest one-cell organism to complex plant and animal species. Offspring resemble the parent but are not identical; there are subtle differences between the generations. “Like produces like”: humans give birth to human babies, dogs have puppies, cows have calves, cats have kittens, and geese have goslings. There are several fundamental concepts involved in the transmission of genes from one generation to the next:

  • HEREDITY EVENTS control the transmission of genetic information to the next generation.
  • DNA is the primary molecule for storage, transmission and expression of characteristics.
  • VARIATIONS IN GENES (DNA sequences on chromosomes) are called alleles, and inheritance patterns can be predicted.
  • MUTATIONS cause alterations in genetic information, which produces variations in people.
  • RANDOM MUTATIONS can be affected by natural selection and genetic drift.
  • Scientific evidence indicates a COMMON ANCESTRY for the origin, development and diversity of all life on earth.

7. Explain Jablonka and Lamb’s inheritance systems.

Jablonka and Lamb believe that along with random genetic mutations, induced and acquired changes also have a role in evolution. Although they present examples of these inheritance systems, each needs more study and observation by other researchers. At this point, the four inheritance concepts outlined by Jablonka and Lamb remain somewhat controversial in the scientific community.

  • THE DNA GENETIC SYSTEM suggests that there are non-random and semi-directed mutations that occur in specific locations in the DNA. These mutations can be caused by the environment and have a greater degree of adaptability than genetic mutations.
  • THE EPIGENETIC INHERITANCE SYSTEM believes characteristics are developed by successive generational differences rather than passed through specific genes.
  • BEHAVIOR is transmitted by example rather than genetics: e.g., food preferences, animals learning how to forage for food, birds learning to sing, mother ducks imprinting their ducklings, tribal traditions observed in chimpanzees and macaques communities.
  • CULTURAL SYMBOLS, especially human language, have evolved and expanded through necessity, for survival and various other factors not easily attributed to genetic transmission.

8. Discuss biodiversity.

Biodiversity (biological diversity) encompasses all living things and the ecosystems they create. It is the Web of Life that has evolved over 3.5 billion years through natural processes and human influences. There are an enormous variety of plants, animals and microorganisms; scientists estimate there may be as many as 100 million species although only about 1.75 million have been identified. Biodiversity includes the chromosomes, genes and DNA of all living species. It also includes earth’s ecosystems in deserts, forests, wetlands, mountains, bodies of water and agricultural areas. To study an ecosystem properly, all living creatures (humans included) that populate the interactive community and share the air, water, and soil must be considered. Life forms and the ecosystems they create produce goods and services that make earth habitable for all living creatures. Some of these goods and services are:

  • Food, fuel, the purification of air and water, and decomposition of waste.
  • Pollination of plants, soil renewal, control of pests and diseases.
  • Shelter and building materials.
  • Culture and beauty.
  • Ability to change.

9. Explain the relationship between living organisms and the environment.

The stability of the environment is predicated on population size, the number and variety of species interacting within the community, and the productivity of the entire ecosystem. The ecosystem can remain fairly stable over long periods of time because of the natural processes at work. For example: the availability of food sources and appropriate shelter for all species, the number of predators and/or parasites in the community, and the occurrence of natural disasters such as fires, floods and droughts. Ecosystems are complex and subject to cyclical fluctuations, such as climate changes and the appearance of new species and disappearance of old ones as a result of mutation, migration, or evolution. Human activities have an enormous influence on the state and stability of the ecosystem, and can alter its equilibrium for better or worse. As the guardians of the earth, it is our responsibility to ensure we respect the other species, protect the various components of the community, and avoid damaging the delicate balance of the ecosystem through misuse of natural resources.

10. Discuss the National Assessment of Educational Progress requirements for assessments in science.

The study of science is divided into three major areas: earth, physical and life sciences. Each of these is sub-divided into specialized fields of study. The U.S. Department of Education established criteria for testing comprehension of science concepts, using recommendations from the National Assessment of Educational Progress. Students are required not only to know facts, but to integrate those facts into previously-learned information by using critical thinking. In other words, students need to be able to apply the facts they learn in class to phenomena found in the real world. The assessments developed by educators, curriculum specialists and the business community emphasize the importance of assessing students’ ability to reason, understand concepts, solve problems, evaluate results, and communicate knowledge of the subject matter. The tests attempt to measure whether students can take cognitive skills learned in science, apply them in other disciplines, and use them outside of school in meaningful ways.