Question 1

A researcher is testing whether a new fertilizer increases plant growth. She sets up two groups: one receives the fertilizer, the other does not. She measures plant height after 4 weeks. Which of the following best describes the null hypothesis for this experiment?

Accepted Answer

There will be no difference in plant height between the two groups.

Question 2

In the famous giraffe study, researchers observed that male giraffes with longer necks were more likely to win fights for mates. What type of study is this, and why?

Accepted Answer

Observational, because the researchers recorded natural behaviors without manipulation.

Question 3

Which of the following is NOT an essential element of a well-designed scientific experiment?

Accepted Answer

Confirmation bias

Question 4

A graph shows the effect of temperature on enzyme activity. The x-axis is labeled 'Temperature (°C)' and the y-axis is labeled 'Enzyme Activity (units/min)'. What type of variable is temperature in this experiment?

Accepted Answer

Independent variable

Question 5

A cross between two pea plants, one with genotype $$YY ($$yellow seeds) and one with genotype $$yy ($$green seeds), produces all $$Yy$$ offspring in the F1 generation. If two F1 plants are crossed, what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

3 yellow : 1 green

Question 6

Which principle explains why alleles for different traits are inherited independently of each other, as observed by Mendel in dihybrid crosses?

Accepted Answer

Principle of Independent Assortment

Question 7

In a cross between $$RrYy$$ and $$rryy$$ pea plants (where $$R = $$round, $$r = $$wrinkled, $$Y = $$yellow, $$y = $$green), what proportion of the offspring will have wrinkled, green seeds?

Accepted Answer

$$\displaystyle \frac{1}{4}$$

Question 8

Which of the following best describes the process of meiosis and its role in generating genetic variation?

Accepted Answer

Meiosis reduces chromosome number by half and introduces variation through crossing over and independent assortment.

Question 9

A mutation occurs in a gene that codes for an enzyme. According to the Central Dogma, which sequence correctly describes the flow of genetic information from this mutated gene to the altered phenotype?

Accepted Answer

DNA $$\rightarrow$$ mRNA $$\rightarrow$$ protein

Question 10

Which of the following best explains why siblings from the same parents can look different from each other?

Accepted Answer

Meiosis creates unique combinations of alleles through independent assortment and crossing over.

Question 11

Which of the following is NOT a component of a DNA nucleotide?

Accepted Answer

A ribose sugar

Question 12

If a diploid organism has a total of 12 chromosomes in its somatic cells, how many chromosomes will its gametes have after meiosis?

Accepted Answer

6

Question 13

A scientist wants to test the effect of a drug on bacterial growth. She sets up 10 petri dishes with bacteria, adds the drug to 5 dishes, and leaves 5 as controls. She measures bacterial colonies after 24 hours. Which aspect of experimental design is she demonstrating by using 10 dishes?

Accepted Answer

Replication

Question 14

Which of the following best describes the structure of double-stranded DNA?

Accepted Answer

Two antiparallel strands held together by hydrogen bonds between complementary bases

Question 15

A woman with genotype $$Aa$$ for a gene marries a man with genotype $$aa. $$What is the probability that their child will be homozygous recessive?

Accepted Answer

$$\displaystyle \frac{1}{2}$$

Question 16

Which of the following scenarios would most likely result in a statistically significant difference between two groups in a scientific study?

Accepted Answer

The means of the groups are far apart and the sample size is large.

Question 17

Which process during meiosis is primarily responsible for the Principle of Segregation?

Accepted Answer

Separation of homologous chromosomes during meiosis I

Question 18

A mutation changes a single base in a DNA sequence from $$A to$$ $$T. $$What is the most likely consequence at the protein level?

Accepted Answer

A possible change in one amino acid in the protein

Question 19

Which of the following best describes the relationship between genotype and phenotype?

Accepted Answer

Genotype determines the sequence of mRNA, which is translated into protein, resulting in phenotype.

Question 20

Which of the following statements about the Central Dogma is correct?

Accepted Answer

Information flows from DNA to RNA to protein.

BIO 150 Exam 1 Study Guide: Scientific Method, Mendelian Genetics, Meiosis, and DNA Structure

Study Guide - Practice Questions

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