Which of the following statements best distingueshes hypothesis from theories in science?a. Theories are hypotheses that have been proved. b. Hypothesees are guesses; theories are correct answers. c. Hypotheses usually are relatively narrow in scope; theories have broad explanatory power. d. Theories are proved true; hypotheses are often contradicted by experimental results.
Answer: c. Hypotheses usually are relatively narrow in scope; theories have broad explanatory power.
In scientific decipline, the hypothesis is a tentative statement which is produced by the method of prediction and assumption based on direct observation of the natural phenomena or event. It can be tested by using the experimental methodology.
Theory is a explaination for the cause of natural event or phenomena. This is based on the evidences obtained after experimental trials. A hypothesis can be used for generation of theory. A theory is more explanatory approach because of the details and evidences than hypothesis. Hence, c is the correct option.
The michaelis constant (km) is analogous to _______ that an enzyme has for its substrate. if the km drops then the enzyme has (gained / lost) affinity and if the km increases then the enzyme has (gained / gained) affinity.
The Michaelis menten constant (Km)
Is analogous to the affinity or the compatibility the particular enzyme has for its given substrate.
If the km drops, then the enzyme has reduced or lost affinity and likewise an increase in the affinity or gain is based on an increase in the value for km.
When viewing a specimen through a light microscope, scientists use ________ to distinguish the individual components of cells.a beam of electrons radioactive isotopes special stains high temperatures
When viewing a specimen through a light microscope, scientists use special stains to distinguish the individual components of cells.
Microscope cell staining -
Microscope cell staining is a method that is used to for the better visualization of the cells and the parts of the cell , when are studied under microscope .
Stains are basically a type of biological tissues .
By the use of different type of stains , a nucleus of the cell or the cell wall of the cell are viewed easily , cells are sometimes stained in order to highlight metabolic process and can be used to find the difference between a dead or a live cell .
Some type of stains are specific for living cells , but some stains can work both for living as well as the non living cells .
An adolescent growth spurt occurs only in boys. a. True b. False
The correct answer is B. False
In development, a growth spurt refers to a period of time in which individuals experience rapid growth or development. In the case of an adolescent growth spurt, this is a natural process that occurs to all individuals including boys and girls during puberty. This takes place because during adolescence the hormone levels change and this leads to rapid growth as well as development or maturation of bones, muscle and the sexual or reproductive system. According to this, it is false an adolescent growth spurt occurs only in boys because this is a natural process that occurs on both girls and boys.
The answer is false Both adolescence males and females have growth spurts
you have selected the following prediction to test: Previously thinned forests will have higher tree survival than adjacent forests that were not thinned. Now you need to define the key variables that you will use to test this prediction. For the following variables, sort them as independent variables, dependent variables, or variables that should be controlled (held constant)1. thinning or no thinning before the fire elevation of the site 2. dominant tree species 3. tree survival rate after the fire A. Independent variableB. Dependent variable C. Controlled variable
A. Independent variable 2. dominant tree species
B. Dependent variable 3. tree survival rate after the fire
C. Controlled variable 1. thinning or no thinning before the fire elevation of the site
A. An independent variable doesn't undergo changes during the experiment because it is not conditioned by other variables in the experiment. In this example, dominant tree species represent a variable that is independent of the experiment itself.
B. A dependent variable is those that you need to measure and depends on the other factors in the experiment. In this example, tree survival is dependent on the factors that affect the results (i.e. humidity in the trees, presence of resinous material in the trees that are non-combustible, etc.)
C. A controlled variable is those that we use to observe an expected outcome in the experiment and therefore it is used to compare with the test group. In this case, thinning or no thinning are used as positive and negative controls, respectively, because they enable their comparison with the test group in the experiment.
7. Wha9. Marfan syndrome is an inherited condition that affects the connective tissue, resulting in unusually long bones and spinal curvature, as well as vision, cardiac, and respiratory problems. The syndrome tends to become increasingly severe over time. The following pedigree shows inheritance of Marfan syndrome in a multigenerational famil (5)y. 8. Wh 5 9. Tra Th the III Be us wi a) How is this syndrome inherited (dominant, recessive or sex-linked)? 2 b) Can you determine individual 114's genotype? Explain. b. с c) Individual III and I12 are considering having another child. What is the probability that this child will have Marfan syndrome? Explain using a Punnett square.
The correct answers are :
a) syndrome Could be autosomal recessive or dominant
b) If it is autosomal recessive - no,
and if it is autosomal dominant - yes, (II-4) - Aa
c) probability of the another child :
Autosomal recessive: Aa x aa 50%
Autosomal dominant: aa x Aa 50%
a) Marfan syndrome could be inherited by the autosomal recessive or dominant pattern on the basis of following characters according the pedigree gives:
- transmitted by anyone regardless of sex male or female
- characters should not skip generations
- A cross between affected person and an normal person should produce approximately half of the affected offspring.
b) Assuming that autosomal dominant than there is two possibilities :
1) in case of I 2 genotype is heterozygous which means it is Aa which will produce Aa Aa aa and aa with crossing with aa as per pedigree however it is incorrect according the offspring given in II.
2) If I 2 is AA- then offspring will be Aa, Aa, Aa and Aa. which is correct according the pedigree.
thus, the answer is - Aa
c) the punnet square as per question is :
II2 - Aa × II1 - aa
a Aa aa
a Aa aa
similar with autosomal recessive
thus, the correct answer is 2 out of 4 that is 50%