Question 1

You are asked to pipette 150 µL of a solution. Which micropipette should you use to ensure the most accurate measurement?

Accepted Answer

A P200 micropipette

Question 2

You need to prepare 100 mL of a 1 M NaCl solution using solid NaCl. Which of the following is the correct sequence of steps?

Accepted Answer

Weigh out the required mass of NaCl, add it to a beaker, add water to reach 100 mL, and mix until dissolved.

Question 3

You are performing a serial dilution with a dilution factor of 1:10 for each step, starting with 1 M HCl. After three serial dilutions, what is the final concentration?

Accepted Answer

$$1 	imes 10$$^{-3}$$ M

Question 4

A solution shows high conductivity when tested with a conductivity meter. What does this indicate about the solute?

Accepted Answer

The solute forms ionic bonds with water and dissociates into ions.

Question 5

A food sample turns blue-black when iodine is added. What does this indicate?

Accepted Answer

The presence of starch in the sample.

Question 6

In an experiment testing the effect of fertilizer on plant growth, which is the dependent variable?

Accepted Answer

Plant growth (e.g., height or biomass)

Question 7

A scatter plot shows that as enzyme concentration increases, reaction rate also increases. What type of correlation is this?

Accepted Answer

Positive correlation

Question 8

Given an absorption spectrum, how do you identify the wavelength of maximum absorbance ($$\lambda_{max}$$)?

Accepted Answer

Find the wavelength where the absorbance value is highest.

Question 9

According to Beer’s Law, what is the relationship between concentration and absorbance?

Accepted Answer

$$A = \varepsilon c l$$

Question 10

A bacterium’s enzyme has an optimal temperature of 70°C. What can you infer about the bacterium’s environment?

Accepted Answer

The bacterium likely lives in a hot environment, such as a hot spring.

Question 11

You are using a microscope with a 10x ocular lens and a 40x objective lens. What is the total magnification?

Accepted Answer

$$10 	imes 40 = 400$$

Question 12

Which of the following is the correct procedure for using oil immersion on a microscope?

Accepted Answer

Place a drop of oil on the slide and use only the 100x objective lens.

Question 13

A plant cell is placed in an unknown NaCl solution. The cell shrinks compared to an isotonic control. What is the tonicity of the unknown solution?

Accepted Answer

Hypertonic

Question 14

A gel electrophoresis image shows two DNA bands for a sample. The individual’s genotype is most likely:

Accepted Answer

HbAHbS (heterozygous for sickle cell)

Question 15

A blood sample agglutinates in anti-A and anti-Rh wells but not in anti-B. What is the blood type?

Accepted Answer

A+

Question 16

Which color of light is least absorbed by chlorophyll during photosynthesis?

Accepted Answer

Green

Question 17

You observe a slide under the microscope and see cells with a prominent nucleus, rectangular shape, and cell wall. Which tissue are you most likely viewing?

Accepted Answer

Onion root tip cells

Question 18

In a photosynthesis experiment, O$$_2$$ production increases in the presence of light. Which process is primarily responsible for this change?

Accepted Answer

Photosynthesis

Question 19

A marine organism adapted to acidic conditions is exposed to a neutral pH. What is the most likely outcome?

Accepted Answer

It may experience stress or reduced function due to the change in pH.

BIOL-141 Final Lab Exam Study Guide: Key Laboratory Skills and Concepts

Study Guide - Practice Questions

Study Guide - Flashcards