Which of the following is supported by the cell theory?
A. Cells are alive and recognized as the building blocks for life.
B. Scientists can identify and differentiate cells by using a microscope
C. Cells are produced from existing cells using meiosis instead of mitosis.
D. Living things are composed of a single cell that remains undifferentiated
After scientists were able to view cells under the microscope they formulated the cell theory. One part of this theory concluded that all cells are alive. They also represent the basic unit of life.
All living things are made of cells. Cells are the smallest structural units and basic building blocks of living things. Cells contain everything necessary to keep living things alive. Varying in size and shape, cells carry out specialized functions. This theory, or in-depth explanation, about cells consists of three parts:
- All living things are composed of one or more cells.
- Cells are alive and represent the basic unit of life.
- All cells are produced from pre-existing cells.
Therefore, the Correct Answer is A.
More Questions on TEAS 7 Science
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Q #1: What type of bond forms between nitrogen and oxygen, and why?
A. Ionic, because electrons are shared
B. Covalent, because electrons are shared
C. Ionic, because electrons are transferred
D. Covalent, because electrons are transferred
Answer Explanation
Nitrogen and oxygen are both nonmetals, which means they will share electrons in a covalent bond. For example, two oxygen atoms form a double bond, in which two pairs of electrons (four electrons total) are shared. Similarly, two nitrogen atoms form a molecule with a triple bond, in which three pairs of electrons (six electrons total) are shared.
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Q #2: A student notices a pattern of stripes on five tigers. Each of the five tigers has the same stripe pattern. Using his inductive reasoning, what does he logically assume based on this information?
A. The pattern continues to change over time.
B. Natural adaptations cause this pattern to occur
C. Each offspring will have the same stripe pattern
D. Ancestors of the tigers have different stripe patterns
Answer Explanation
Inductive reasoning involves making specific observations and using them to make broad statements. The student observes that all of the tigers have the same stripe pattern. He can use this observation to make the broad statement that all the tigers’ offspring will have the same stripe pattern.
Inductive reasoning involves drawing a general conclusion from specific observations. This form of reasoning is referred to as the “from the bottom up” approach. Information gathered from specific observations can be used to make a general conclusion about the topic under investigation. In other words, conclusions are based on observed patterns in data.
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Q #3: Which statement best represents Mendel’s experiments with garden peas?
A. As a result, Mendel developed several theories that have since been disproved.
B. Mendel realized he was on an incorrect track, which led him to other experimental media
C. As a result, Mendel developed foundational conclusions that are still valued and followed today.
D. Mendel collaborated with others interested in genetics to develop heredity guidelines we still use today
Answer Explanation
Mendel developed theories of genetics that scientists around the world use today.
From experiments with garden peas, Mendel developed a simple set of rules that accurately predicted patterns of heredity. He discovered that plants either self-pollinate or cross-pollinate, when the pollen from one plant fertilizes the pistil of another plant. He also discovered that traits are either dominant or recessive. Dominant traits are expressed, and recessive traits are hidden.
Mendel’s Theory of Heredity
To explain his results, Mendel proposed a theory that has become the foundation of the science of genetics. The theory has five elements:
- Parents do not transmit traits directly to their offspring. Rather, they pass on units of information called genes.
- For each trait, an individual has two factors: one from each parent. If the two factors have the same information, the individual is homozygous for that trait. If the two factors are different, the individual is heterozygous for that trait. Each copy of a factor, or gene, is called an allele.
- The alleles determine the physical appearance, or phenotype. The set of alleles an individual has is its genotype.
- An individual receives one allele from each parent.
- The presence of an allele does not guarantee that the trait will be expressed.
