Biology Progress Check: Microscopes and Cells

Progress Check 1

• Simple microscope described as a microscope with a single biconvex lens
• Concave mirror was used to direct light onto the object, as per Hooke's microscope.
• Maximum magnification of a compound microscope typically reaches 2000 times.
• The maximum magnification of an electron microscope normally reaches 200,000 times.

Progress Check 2

• Bacteria and Amoeba listed as examples of one-celled organisms.
• Nerve cells identified as the longest cells in animals.
• White blood cells have an amoeboid shape.
• A large surface area to volume ratio in cells facilitates easier diffusion of nutrients, metabolic wastes, and respiratory gases.

Progress Check 3

• Many chemical reactions occur within the cytoplasm, aided by enzymes.
• Nucleoplasm is where a network of chromatin fibres is found.
• Cellulose is the major component of cell walls.
• An organ is larger and visible to the naked eye, while an organelle is microscopic. Plants have plastids, whereas animal cells do not.

Question 4 (page 3)

• Cell wall is a component made of cellulose.
• Endoplasmic Reticulum is an irregular network of tubular double membranes.
• A clear space with water or other substances within the cell is termed a vacuole.
• Chromosomes are visible only during cell division.
• Prokaryotic cells have smaller ribosomes than eukaryotic.
• Eukaryotic cells have mitochondria.
• Amoeba is a eukaryotic organism, not prokaryotic.
• Bacteria do not have a nuclear membrane.

Question 5 (page 3)

• The cell organelles involved in secretion of enzymes are Golgi complexes and Dictyosomes.
• Solar energy is trapped by chloroplasts.
• Synthesis of proteins occurs in ribosomes.
• Intracellular digestion occurs in lysosomes.
• The production of ATP occurs in mitochondria.

Question 7 (page 7)

• The Golgi apparatus is involved in the formation of the acrosome within a sperm.

Question 8 (page 7)

• The nucleolus takes part in protein synthesis within the cell nucleus.

Question 9 (page 7)

• Anthocyanin is a pigment which is not found in plastids.

Question 10 (page 7)

• Tubules within Golgi Complexes are referred to as cisternae.

Progress Check 4 (page 4-5)

• Repair - Contractility of the cell
• Cooling of the body - Gland cells releasing sweat
• Movement - Contractility of the cell
• Protection from disease - Cells destroying germs
• The nucleus is the key to a cell's life.
• Cells, like organisms, have a lifespan and undergo death; red blood cells last approximately 120 days.
• Waste substances are expelled from a cell similar to an organism expelling waste.

Progress Check 5 (page 5)

• Cells need food for various processes. Glucose is converted to ATP for energy by respiration.
• Cellular life begins with a single cell.
• Both plant and animal cells contain a cell membrane.

Question 8 (page 11)

• Petals of a sunflower contain chromoplasts; ripe tomatoes have anthocyanin; green mangoes have chlorophyll; and potato cells lack any specific pigment.

Question 1 (Short Answer) (page 11)

• Cell organelles have a specialized structure and function.
• Cell inclusions include substances such as nutrients or pigments.
• Cytosol is the liquid interior of a cell where components are dispersed.
• Cell sap exists within the vacuoles.
• Cytoplasm encompasses the cytosol and cell organelles.

Question 2 (page 12)

• Animal cells do not have cell walls.
• Cell walls are made from cellulose.
• Centrosomes are present in animal cells.
• Plant cells have large vacuoles.
• The protoplasm surrounds the nucleus.
• Genes reside within chromosomes.
• Anthocyanins are pigments dissolved in cell sap.

Question 3 (page 12)

• A human cell contains 23 chromosome pairs.

Question 4 (page 12)

• Deoxyribonucleic acid (DNA) constitutes genes.

Question 6 (page 12)

• Lysosomes are membrane sacs that release 40 different digestive enzymes.
• Microtubules surround centrioles, located near the nucleus.
• Cell membranes are thin, flexible, living membranes that selectively permeabilise the cells.
• Certain cells, like certain insects' cells, have over 1000 chromosomes.
• Genes are hereditary units.
• A plastid that stores starch is a leucoplast.

Question 7 (page 12)

• The full forms of the abbreviations: DNA, RNA, ATP (Deoxyribonucleic acid, Ribonucleic acid, Adenosine triphosphate).

Question 2(page 13-14)

• Protoplasm is the total living matter of a cell. Its parts are the nucleus and the cytoplasm.
• Cytoplasm is a mixture of insoluble and soluble cell components.
• A cell's nucleus houses a nucleolus, which is round and spherical, while the nucleus is dense and has thread-like chromatin fibers.
• A centrosome has two centrioles, from which spindle fibers develop during cell division. Chromosomes hold genes—inherited traits from parents.
• Cell walls, nonliving and rigid, are contrasted to cell membranes, the cell's flexible outer structure.

Question 2(page 15)

• Plant cell walls are made of cellulose.
• Plant cells have centrosomes absent, but plastids are usually present.

Question 2 (page 15/16)

• Prokaryotes have a rudimentary nucleus, and lack other cell organelles other than ribosomes; they have smaller ribosomes compared to eukaryotes. Examples include blue-green algae. Eukaryotes have a well-formed nucleus and other organelles; they have larger ribosomes. Examples include humans.

Question 3 (page 15-16)

• Functions of Plasma membrane, Ribosome, Lysosomes, Mitochondria, and Golgi apparatus are elucidated within the text.

Question 4 (page 17)

• The differences between a living cell and a brick are analysed in the text, which includes details on non-rigid structure, cellulose content and function, and permeability of the living cell.

Question 5 (page 17)

• Six features shared by plant and animal cells are detailed in the text.

Question 1 (page 18)

• Identify plant and animal cells based on their morphology and component analysis.
• Identify common organelles (within both plant and animal cells) or specialized ones (present only in plant or animal cells).