Validity refers to whether a study measures or examines what it claims to measure or examine. when looking at experiments it is possible to evaluate the validity of the procedure of a study.
internal validity dictates how an experimental design is structured and encompasses all of the steps of the scientific research method.
even if your results are great, sloppy and inconsistent design will compromise your integrity in the eyes of the scientific community. internal validity and reliability are at the core of any experimental design. external validity is the process of examining the results and questioning whether there are any other possible causal relationships.

can you determine which instances reflect a valid experiment or conclusion? check only those that are valid.

a biology class is conducting an experiment to determine how soil ph affects the germination of pine seedlings. 30 pine seeds are placed in pots of soil with varying ph levels: 4.5, 6.5, 7.0, 7.5, 8.5, and 9.0. pot size, water, and light exposure were constant for all pots.

a marine biologist is examining the effects of oil pollution on a population of seagulls (larus canus). he is particularly interested in determining whether oil pollution reduces the number of eggs that may be hatched in each seagull nest. during one breeding season, he has counted the number of eggs present in 16 seagull nests and recorded the distance from each nest to a nearby oil refinery.

after months of grueling research drinking many, many colas, karl has come to the conclusion that brand a cola tastes better than brand b cola.

jeanette was conducting an experiment to determine if plants grow better when exposed to rap music. she bought two identical plants and exposed one to rap music for two weeks while the other grew without music. from the data, jeanette determined that plants do not grow better with rap music.

robert is instructed in a lab experiment to first record the ambient temperature of the room. to do this, he holds the thermometer under a bright light to accurately read it. he then reads and records the data as 33°c.

Question 1(multiple choice worth 3 points) (06.04 lc) which of the following is true about repetition in an experiment? it involves setting up of a hypothesis. it involves multiple trials. it involves data analysis. it involves peer review. question 2(multiple choice worth 3 points) (06.03 mc) the trait for flower color in a plant has red and white alleles. the red color is the dominant trait. what is the phenotypic ratio for a cross between plants with red (rr) flowers and white (rr) flowers? 4 red : 0 white 3 red : 1 white 2 red : 2 white 0 red : 4 white question 3(multiple choice worth 3 points) (06.01 mc) the following table describes some biotechnological processes. biotechnological processes process description 1 producing offspring that have identical dna as one parent 2 crossing a high-yielding fruit variety with a high-vitamin variety which biotechnological processes are described in the table? both processes describe cloning. both processes describe genetic engineering. process 1 describes cloning and process 2 describes artificial selection. process 1 describes artificial selection and process 2 describes cloning. question 4(multiple choice worth 3 points) (05.04 mc) which of the following adaptations best polar bears walk on snow? furry feet slippery feet small feet white-colored feet question 5(multiple choice worth 3 points) (06.01 hc) a team of scientists altered the dna of e. coli bacteria. the bacteria thus developed had the ability to generate insulin exactly identical to the human insulin molecule. what could be the likely impact of this biotechnology on the individual and the society? the medical costs for insulin-dependent patients would rise. large-scale insulin could be produced in relatively lesser time. the price of insulin available from sources other than bacteria may fall. the patients who take insulin may become infected with e. coli bacteria. question 6(multiple choice worth 3 points) (06.03 lc) which of the following is used to represent a recessive trait in a punnett square? an uppercase letter a lowercase letter a shaded square a shaded circle question 7(multiple choice worth 3 points) (06.03 mc) cystic fibrosis is a recessive gene disorder. the pedigree chart for a family known to have cystic fibrosis is shown below. a half shaded circle is shown connected by a straight line to an unshaded square. underneath the half shaded circle are the letters aa which represent the genotype for the first parent. underneath the second parent the letters, aa, appear representing the genotype for the other parent. below this is another row of circles and squares. this 2nd row represents the offspring. starting from the left a half shaded circle is shown connected to an unshaded square, followed by an unshaded square, and then an unshaded circle. each of the circles and squares, offspring, are connected by a horizontal straight line that connects to the parent group above. the genotype is written under each of the offspring in order from left to right; aa, aa, aa, aa. what percentage of the offspring have observable disease? 0% 25% 50% 75% question 8(multiple choice worth 3 points) (06.03 lc) which of the following is an example of a homozygous recessive allele? rr rr rr rw question 9(multiple choice worth 3 points) (06.03 mc) the pod color in pea plant can be yellow or green. a pea plant with yellow pods (yy) is crossbred with another pea plant with green pods (yy). what is the probability of offspring with green pods? 0% 25% 50% 75% question 10(multiple choice worth 3 points) (06.02 mc) a pea plant has white flowers. it has a genotype pp. which of the following about the gene of flower color in the pea plant is true? the allele for white flowers is dominant in the pea plant. the allele for white flowers is recessive in the pea plant. the plant received both dominant alleles from both the parents. the plant received a dominant and a recessive allele from each parent. the characteristics of certain cell divisions are described in the following table. cell division characteristics characteristic description 1 forms diploid cells 2 creates sex cells, or gametes which type(s) of cell division do the two characteristics represent? both characteristics represent meiosis. both characteristics represent mitosis. characteristic 1 represents meiosis and characteristic 2 represents mitosis. characteristic 1 represents mitosis and characteristic 2 represents meiosis.

Based on the data in your tables, did the light-colored moths have a higher or lower survival rate after the industrial revolution?

Match the reproductive structures based on their function and the system to which they belong. egg ovary sperm vas deferens vagina fallopian tube testis urethra