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
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.
Therefore, the Correct Answer is D.
More Questions on TEAS 7 Science
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Q #1: What is the final structure through which urine must travel to empty out of the body?
A. Bladder
B. Kidney
C. Ureter
D. Urethra
Answer Explanation
The primary organ of the urinary system is the kidney. Blood from the heart flows through the kidneys via the renal artery. As blood drains from the kidney, it exits through a series of veins, the most prominent of which is the renal vein. When urine is produced, it does not drain through the tubes through which blood flows. Rather, urine flows through two ureters before emptying into the urinary bladder.
The following steps outline how the urinary system works:
- Kidney filters and excretes wastes from blood, producing urine.
- Urine flows down the ureters.
- Urine empties into the bladder and is temporarily stored.
- Bladder, when filled, empties urine out of the body via the urethra.
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Q #2: What raw inorganic material would an autotroph most likely use to create chemical energy for growth?
A. carbon dioxide
B. minerals in soil
C. decaying matter
D. sugar molecules
Answer Explanation
Autotrophs are organisms that use basic raw materials in nature, like the sun, to make energy-rich biomolecules. Minerals are naturally inorganic.
Autotrophs are organisms that make energy-rich biomolecules from raw material in nature. They do this by using basic energy sources such the sun. This explains why most autotrophs rely on photosynthesis to transform sunlight into usable food that can produce energy necessary for life. Plants and certain species of bacteria are autotrophs.
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Q #3: A spoonful of sugar is added to a hot cup of tea. All the sugar dissolves. How can the resulting solution be described?
A. Saturated and homogeneous
B. Saturated and heterogeneous
C. Unsaturated and homogeneous
D. Unsaturated and heterogeneous
Answer Explanation
Because more solute could be added and dissolve, the solution has not yet reached its limit and is considered unsaturated. Because all the solute dissolves, the particles in the mixture are evenly distributed as a homogenous mixture.
- A mixture is when elements and compounds are physically, but not chemically, combined.
- A homogeneous mixture is when substances mix evenly and it is impossible to see individual components. A heterogeneous mixture is when the substances mix unevenly and it is possible to see individual components.
- A solution is a type of homogeneous mixture that is formed when a solute dissolves in a solvent.
- The concentration of a solution is the amount of a substance in a given amount of solution. An unsaturated solution has the ability to dissolve more solute and a saturated solution has already reached the limit of solute it can dissolve.
