12STEM2509 SSGBIO1 Midterm Long Quiz

In a biology lab, Grace is preparing to observe a slide under the microscope. She needs to adjust the part of the microscope that controls the angle and amount of light reaching the specimen. Which part should she adjust?

• Stage

• Condenser and diaphragm

• Nosepiece

• Illuminator

Answer explanation

The condenser and diaphragm work together to control the angle and amount of light that illuminates the specimen, enhancing visibility and contrast. The stage holds the specimen, while the nosepiece and illuminator serve different functions.

Henry is using a microscope in his biology lab. If the ocular lens has a magnification of 10× and he sets the objective lens to high power at 40×, what is the total magnification he will achieve?

• 40×

• 100×

• 400×

• 1000×

Answer explanation

Total magnification is calculated by multiplying the ocular lens magnification (10×) by the objective lens magnification (40×). Thus, 10× × 40× = 400×, making 400× the correct answer.

During a biology lab, David is trying to observe a specimen under a microscope at high magnification. He learns that certain techniques can improve resolution by reducing refraction. What technique should he use?

• Heat fixation

• Staining

• Oil immersion

• Iris diaphragm

Answer explanation

Oil immersion improves resolution by using a special oil that has a refractive index similar to glass, reducing light refraction at high magnification. This allows for clearer and more detailed images compared to other methods.

In a small laboratory, Harper, a curious scientist, is fascinated by the microscopic world. One day, while using a microscope, he discovers tiny organisms swimming in a drop of water. He recalls the work of Anton van Leeuwenhoek, who is known for:

• Coining the term "cell"

• Observing bacteria and protozoa

• Proposing cells come from pre-existing cells

• Discovering chromosomes

Answer explanation

Anton van Leeuwenhoek is renowned for his pioneering work in microscopy, which allowed him to observe bacteria and protozoa for the first time, significantly advancing our understanding of microbiology.

In a biology class, Mia is explaining the differences between prokaryotic and eukaryotic cells. She asks her classmates, "Which structure is present in prokaryotes but not in eukaryotes?"

• Ribosome (70S)

• Nucleus

• Mitochondria

• Endoplasmic reticulum

Answer explanation

Ribosomes in prokaryotes are 70S, while eukaryotes have 80S ribosomes. Prokaryotes lack membrane-bound organelles like a nucleus, mitochondria, and endoplasmic reticulum, making 70S ribosomes a unique feature of prokaryotic cells.

In a bustling factory, workers on the assembly line are responsible for creating various products. Some workers are stationed at a section of the line that focuses on packaging and shipping finished goods. These workers are mainly involved in:

• Lipid synthesis

• DNA replication

• Protein secretion

• Cell wall construction

Answer explanation

Ribosomes bound to the rough ER primarily synthesize proteins that are secreted from the cell. This process is crucial for producing enzymes and hormones that are released into the bloodstream or other tissues.

In a bustling city, there is a power plant known for its efficiency in generating electricity, which is essential for the city's operations. This power plant is often referred to as the "powerhouse of the city". Which facility in the city is responsible for generating this vital energy?

• Waste Management Facility

• Water Treatment Plant

• Power Plant

• Recycling Center

Answer explanation

The mitochondrion is known as the "powerhouse of the cell" because it is responsible for producing ATP, the main energy currency of the cell, through cellular respiration.

During a science fair, Mia is demonstrating how cells divide. She explains that the structure responsible for pulling the chromosomes apart during mitosis is similar to a construction crew using specific tools to build a structure. Which cytoskeletal element forms the mitotic spindle?

• Microfilaments

• Microtubules

• Intermediate filaments

• Actin filaments

Answer explanation

Microtubules are the cytoskeletal elements that form the mitotic spindle, which is essential for separating chromosomes during cell division. Microfilaments and intermediate filaments serve different functions in the cell.

In a busy laboratory, Abigail is responsible for managing various chemical reactions. One day, she notices that some of the chemicals are producing hydrogen peroxide as a byproduct. To ensure safety and maintain a clean workspace, she needs to identify which organelle in the cell is primarily responsible for detoxifying hydrogen peroxide.

• Break down glucose

• Digest proteins

• Detoxify hydrogen peroxide

• Store calcium

Answer explanation

Peroxisomes primarily function to detoxify hydrogen peroxide, a harmful byproduct of cellular metabolism, by converting it into water and oxygen. This makes 'Detoxify hydrogen peroxide' the correct answer.

During a crucial moment in a science lab, Charlotte is overseeing a team of researchers who are preparing to separate chromosomes for analysis. She needs to ensure that all chromosomes are properly attached to the spindle fibers before they proceed with the separation. Which checkpoint should Charlotte focus on to confirm this?

• G1/S checkpoint

• G2/M checkpoint

• Spindle assembly checkpoint

• Apoptosis checkpoint

Answer explanation

The spindle assembly checkpoint ensures that all chromosomes are correctly attached to spindle fibers before they are separated during cell division, preventing errors in chromosome distribution.