Topic 1 Biology Review

How do you calculate mitotic index?

(Cells in mitosis/Total # of cells) Times 100

The electron micrograph shows a thin section through a plant mesophyll cell. What is the magnification of the image? Image size: 3 cm (0.03 m) Actual size: 10 micrometers (10 times 10^-6 m)

3000

Animal cells often secrete glycoproteins as extracellular components. What is a role of these glycoproteins? * A. Adhesion B. Additional energy reserve C. Membrane fluidity D. Water uptake

A

Dialysis membrane was set up to model digestion and absorption in the small intestine. What is a limitation of this model? A. There can be no active transport. B. Maltose will pass through the membrane. C. Lipase should be present with protein. D. The membrane is not permeable to starch.

A

The image shows an electron micrograph of part of a cell. Which features do the two structures labelled X (Chloroplast) and Y (Nucleus) have in common? A. They are surrounded by a double membrane. B. They contain 70S ribosomes. C. They contain naked DNA. D. They are only found in leaf cells.

A

What evidence from the image of Paramecium indicates whether the organism is a prokaryote or a eukaryote? * A. Compartments in the cell indicate that it is a eukaryote. B. No nucleus indicates that the cell is a prokaryote. C. Lack of a cell wall indicates that the cell is a eukaryote. D. It is a unicellular organism, so it must be a prokaryote.

A

What feature of both striated muscle and aseptate fungal hyphae is different from typical cell structure? A. They have multiple nuclei within a structural unit. B. They have a cell wall that is not made of cellulose. C. They have plasmids. D. They have an absence of cholesterol in the plasma membrane.

A

What is osmosis? * A. The movement of water through a membrane from a low to a high solute concentration B. The movement of solutes through a membrane from a high to a low water concentration C. The movement of water through a membrane from a high to a low solute concentration D. The movement of solutes through a membrane from a low to a high water concentration

A

What is an integral (intrinsic) protein and where is it located?

A protein that is permanently inside that the plasma membrane; It allows specific molecules to pass through it during active diffusion

How does mitosis produce two genetically identical nuclei? * A. By separation of homologous chromosomes B. By separation of sister chromatids C. By division of the cytoplasm into two equal cells D. By division of the nuclear membrane into two equal parts

B

How does potassium move across the membrane of a neuron during repolarization? * A. Simple diffusion B. Facilitated diffusion C. Endocytosis D. Active transport

B

Pasteur carried out a series of experiments that provided strong evidence against a widely supported theory. What was this theory? * A. Endosymbiosis B. Spontaneous generation C. Conservative replication of DNA D. Evolution

B

What is a role of cholesterol in animal cells? * A. It increases body fat. B. It controls membrane fluidity. C. It lines the inner wall of capillaries. D. It is a constituent of bile

B

What phase of mitosis is the cell in the picture in? A. Prophase B. Metaphase C. Anaphase D. Telophase

B

Which molecule regulates the fluidity of cell membranes? * A. Phospholipid B. Cholesterol C. Glycoprotein D. Peripheral protein

B

Which process(es) occur(s) by osmosis? I. Uptake of water by cells in the wall of the intestine II. Loss of water from a plant cell in a hypertonic environment III. Evaporation of water from sweat on the skin surface * A. I only B. I and II only C. II and III only D. I, II and III

B

Which statement provides evidence for endosymbiosis? * A. Early prokaryotes contributed to a large increase in oxygen in the atmosphere. B. Eukaryotic mitochondria and chloroplasts have their own circular DNA. C. Only eukaryotic mitochondria have their own circular DNA. D. Experiments by Miller and Urey produced simple organic molecules in abiotic conditions.

B

Which structures are found only in prokaryotic cells? * A. Ribosomes B. Pili C. Cell walls D. Flagella

B

By which process do potassium ions move through potassium channels in axons? * A. Active transport B. Exocytosis C. Facilitated diffusion D. Simple diffusion

C

From the diagram pictured, which part of the membrane structure does the molecule below form? A. Integral protein B. Carbohydrates C. Phospholipid D. Glycoprotein

C

The cell membrane model proposed by Davson-Danielli was a phospholipid bilayer sandwiched between two layers of globular protein. Which evidence led to the acceptance of the Singer-Nicolson model? * A. The orientation of the hydrophilic phospholipid heads towards the proteins B. The formation of a hydrophobic region on the surface of the membrane C. The placement of integral and peripheral proteins in the membrane D. The interactions due to amphipathic properties of phospholipids

C

The concentrations of cyclins rise and fall in cells at certain times. What times are these? * A. Day and night B. Seasons of the year C. Stages of mitosis and interphase D. Developmental stages in the life cycle

C

What did the experiments done by Louis Pasteur suggest? A. Mold evolved by endosymbiosis. B. Oxygen is required for anaerobic respiration. C. Cells can only be formed by division of pre-existing cells. D. Nutrients are a requirement for mold growth.

C

What part of the plasma membrane is fluid, allowing the movement of proteins in accordance with the fluid mosaic model? A. Glycoprotein B. Peripheral proteins C. Phospholipids (Hydrophobic tail, hydrophilic head) D. Integral proteins

C

What phase of mitosis is this cell in? A. Prophase B. Metaphase C. Anaphase D. Telophase

C

The salt concentration inside an animal cell is 1.8 %. The salt concentration in the surrounding medium becomes 5 %. What will be the likely response? * A. The cell will gain water from the medium. B. The cell will lose salt to the medium. C. The cell will remain unchanged. D. The cell will shrink from loss of water.

D

What is evidence for the endosymbiotic theory? * A. RNA can catalyse metabolic reactions. B. Meteorites contain organic molecules. C. Amino acids can be synthesized from inorganic compounds. D. Mitochondria possess their own DNA

D

When during the cell cycle does DNA replication take place? A. Mitosis B. Interphase C. G1 Phase D. S phase

D

Why is there a higher concentration of Potassium ions inside a cell and a higher concentration of Sodium ions outside a cell? A. Potassium ions diffuse in and sodium ions diffuse out. B. Sodium ions diffuse in and potassium ions diffuse out. C. Active transport pumps sodium ions in and potassium ions out. D. Active transport pumps sodium ions out and potassium ions in

D

What happens to the cell surface area to volume ratio with increasing cell diameter?

The cell surface to volume ratio exponentially decreases as cell diameter increases

Which characteristic of stem cells makes them useful for treating Stargardt's disease?

They can differentiate into retinal cells.

What happens in asexual reproduction?

a single individual passes all of its genes to its offspring