A Level Biology Q&A Mastery Package

ch 2 A substance that cannot be broken down into other substances by ordinary chemical procedures is a(n) ________. element Which of the following is a trace element required by most living organisms? magnesium The innermost electron shell of an atom can hold up to _______ electrons. 2 Whic...

How is a community different from an ecosystem? A community consists of all of the interacting populations in an ecosystem. An ecosystem includes the non-living components that affect life as well as all of the interacting populations in a given area. Explain why methicillin resistant Staphloco...

Hydrogen Most organic compounds contain carbon and _______ C-C bonds are as strong as C-O bonds why is life based on carbon compounds It can form a variety of carbon skeletons and host functional groups Why is carbon so important in biology Both can carbon form polar or nonpolar bonds The majo...

Animals that migrate great distances would obtain the greatest energetic benefit of storing chemical energy as _____. fats The "essential nutrients" for proper human nutrition include _____. calcium, sodium, potassium, and other minerals Which pair correctly associates a physiological proces...

Interphase Nucleoli are present during _____. Telophase Cytokinesis often, but not always, accompanies _____. Prophase Chromosomes become visible during _____. Anaphase Centromeres divide and sister chromatids become full-fledged chromosomes during _____. Prometaphase Spindle fibers attach to ...

Describe how you would use a biochemical test to show that a solution contained a nonreducing sugar, such as sucrose. [3] ,first reducing sugars test; boil with dilute HCl acid then Neutralise with NaHCǑ, add benedict and heat to 95 degrees C brick red ppt forms if reducing sugar is present D...

What are the three ways a pathogen can damage hosts cells? 1) rupturing them to release nutrients inside them 2) breaking down nutrients inside the cell for their own use. This starves and eventually kills the cell. 3) replicating inside the cells and bursting them when they're released What...

What is RNA? ribonucleic acid MRNA and TRNA Single stranded Shorter AU CG What are biological molecules? molecules made and used by living organisms eg. Lipids, carbs, DNA, AT, water, inorganic ions What are the functions of carbohydrates? -energy source (respiration) -energy store (starch ...

Large molecules often contain carbon. Why? they can readily form bonds with other carbon atoms. This forms a 'backbone'. Other atoms can then attach. Describe benedicts test for reducing sugars add equal volumes of the sugar sample and benedicts reagent. Heat the mixture in a water bath for ...

Transcription helix unzips by DNA polymerase Strands separate, acts as template Free RNA nucleotides attach to completmentary base Phosphate bonds form Pre-MRNA detaches Splicing=removes introns-non coding Translation Ribosome attaches to start condon TRNA with complementary anticodon pairs ...

Why do specimens need to be thin when observing them under a light microscope? to allow light to pass through Identify and explain the starch test add iodine dissolved in potassium iodide solution to the sample - positive test = blue-black - negative test = orange-brown Why is the structure ...

How do biological molecules provide evidence for evolution? They all have similar molecules and use the same amino acids and DNA. What are monomers of carbohydrates called? Monosaccharides. Beta Glucose Alpha glucose Glucose formula C₆H₁₂O₆ Name of the bond between monosaccharides? ...

Abiotic components Components of an ecosystem that are non living Abiotic factors Non living components of an ecosystem that effect other living organisms Acetycholine Chemical that acts as a transmitter that diffuses across synaptic cleft Acetycholinesterase Enzyme in synaptic cleft that break...

Describe and explain the steps in the light dependent reaction of photosynthesis 1. Photoionisation: light reaches chlorophyll in psii, which is absorbed by an electron, which becomes excited and moves to a higher energy level. 2. The electron passes to a carrier protein in the thylakoid membra...

Define variation Differences that exist between individuals In what ways can variation be caused? It can be caused by genetic factors, such as alleles from mutations. It can also be caused by the environment, such as climate. Most variation is caused by a combination of genetic factors and envi...

What are monomers? Monomers are *small units* which are the components of larger molecules. What are polymers? Polymers are molecules made from *many monomers* joined together. What are examples of monomers? *Monosaccharides, amino acids* and *nucleotides* What are examples of polymers? *Po...

Monomers Small basic molecular units Examples of monomers monosaccharides, amino acids and nucleotides Polymers Large complex molecules composed of long chains of monomers joined together Examples of polymers Carbohydrates, proteins and nucleic acids What type of sugar is glucose? Hexose How ...

What is a light microscope used for? Observing living and dead specimens What are the pros and cons of a light microscope? Pros: Cheap, portable, easy to use, can study living specimens. Cons: Limited magnification, poor resolution. What is a laser scanning confocal microscope used for? Creating...

What does it mean when ecosystems are described as dynamic? they are constantly changing What is succession? the process by which ecosystems can change over time Where does primary succession take place? an area of land that has been newly formed or exposed meaning there is no soil or organic ...

What is the purpose of respiration ? To release energy from glucose To produce ATP What is the general equation for aerobic respiration ? 6O2 + C6H1206 --> 6H2O + 6CO2 + energy What do plants need energy for ? (name 5) 1. Photosynthesis 2. Active transport of minerals via roots 3. DNA repl...

Structure of Nucleus. 1. Nuclear envelope: double membrane surrounding nucleus, outer membrane continuous with the (R)ER of the cell. 2. Nuclear pores: allow the passage of larger molecules, such as mRNA, out of the nucleus. 3. Nucleoplasm: granular, jelly-like material making up the bulk of t...

Explain why the data in the table above are described as processed results. (1) Calculations made from the raw data Describe how you would use a 1.0 mol dm−3 solution of sucrose to produce 30 cm3 of a 0.15 mol dm−3 solution of sucrose (2) *Use ratios 0.15 : 0.85 Add 4.5 cm3 of (1.0 mol d...

What affects the amount of material that is exchanged in an organism? size and metabolic rate- higher metabolic rate= more materials exchanged Name 4 things that need to be exchanged between an organism and their environment. - respiratory gases - nutrients - excretory products - heat How d...

What is a mutation? A change in the DNA sequence What are the 6 types of mutation? (Things that happen with bases) Substitution Deletion Addition Duplication Inversion Translocation What is a hereditary mutation? When a gameate containing a mutation for a type of cancer or genetic disorder...

Why are Microorganisms able to perform exchange via their surface? • have a large surface area to volume ratio • have a short diffusion distance • have low demand How do Microorganisms Obtain Nutrients & Remove Waste? • by exchange via their surface • nutrients (e.g. glucose, oxyge...

What is photosynthesis? Occurs ONLY in plants. The plant makes glucose from light, carbon dioxide and water What is the equation for photosynthesis? 6CO2 + 6H2O -> C6H12O6 + 6O2 How is energy stored in plants? In the glucose until plants release it by respiration What is a metabolic pathway?...

Define monomer The smaller units from which larger molecules are made (via condensation reactions). List examples of monomers Monosaccharides Amino acids Nucleotides Define polymer Molecules made from large number of monomers joined together (via condensation reactions). Define Condensation...

What is a stimulus? A change in the environment of an organism What is a tactic response? Directional movement in response to a stimulus What is a kinetic response? Non directional random movement in response to a stimulus What is a positive and negative taxis? Positive taxis- organism moves to...

Tissue a group of specialised cells Organ made of different tissues Organ system different organs working together What is an Animal Cell made of? 1. Organelles (nucleus, endoplasmic reticulum, golgi body, lysosomes, mitochondria, ribosomes) - all have membrane except the ribosomes 2. Cytopl...