2704341
| Question | Answer |
| What is produced when yeast cells break down sugar in the absence of oxygen? | Ethanol and carbon dioxide |
| What is the anaerobic respiration of yeast often called? | Fermentation |
| Adaptations of fat cells? | Can expand as they fill with fat They have few mitochondria as they need little energy Small amount of cytoplasm, large amounts of fat |
| Adaptations of cone cells? | Outer segment contains a visual pigment, which changes chemically in coloured light. Middle segment is packed with mitochondria, which releases energy needed to reform visual pigment. (Helps you continually see in colour) Synapses connect to optic nerve. |
| Adaptations of root hair cells? | Root hairs increase SA so more water and mineral ions can be absorbed from the soil. Large permanent vacuole speeds up movement of water. |
| Adaptations of sperm cells? | Long tail whips from side to side to help sperm move toward the egg. Middle section full of mitochondria, provides energy for cell to work. Acromosome stores digestive enzymes for breaking down outer layers of egg. Large nucleus contains genetic info to be passed on. |
| What is diffusion? | The net movement of particles from a region of high concentration to a region of low concentration. |
| Factors that affect diffusion | Steepness of the concentration gradient Temperature (makes particles move faster) How high the SA/Volume ratio is. How short the diffusion distance is. |
| What is a tissue? | A group of cells, e.g. muscular tissue. |
| What is an organ? | Contains +1 tissue working together, e.g. <3 |
| What is an organ system? | Several organs all involved in performing a function. |
| What do muscular tissues do? | Contract to bring about movement. |
| What do glandular tissues do? | Contain secretory cells that can produce substances such as enzymes and hormones. |
| What do epithelial tissues do? | Cover the outside of your body and your internal organs. |
| What do epidermal tissues do? | Cover surfaces and protect them. |
| What do mesophyll tissues do? | Contain lots of chloroplasts and can carry out photosynthesis. |
| What do xylem and phloem tissues do? | Carry water and mineral ions around the plant. |
| Leaf adaptations | Broad, giving them a big SA for light to fall on. Contain chlorophyll in chloroplasts to absorb light energy. Air spaces that allow diffusion. Veins bring plenty of water to the cells of the leaves. |
| How do plants use glucose? | 1. For respiration. 2. Convert into insoluble starch for storage. 3. Combine with mineral ions in soil to make amino acids. 4. Build up fats + oils to use as an energy store + make cells stronger. 5. Produce fats, proteins and cellulose to be used in cells or cell walls. |
| Why do plants need amino acids? | To build up into proteins to be used in the cells. |
| How do plants make amino acids?? | Combining sugars with nitrate ions and other mineral ions from the soil. |
| Advantage of hydroponics? | Plants are grown in water with a perfect balance of mineral ions instead of soil, so nothing slows down their growth. |
| What 5 factors affect living organisms? | Nutrients Temperature Amount of light Availability of water Availability of oxygen and carbon dioxide |
| What physical factors can you measure by counting along a transect? | Light levels Soil pH |
| Function of a nucleus | Controls all activities in a cell. Contains genes on chromosomes. Carry instructions for making new cells/organisms. |
| Function of a cell membrane | Controls passage of substances into and out of a cell. |
| Mitochondria | Structures in cytoplasm where oxygen is used and energy is released in respiration. |
| Function of cytoplasm | Liquid gel where most chemical reactions needed for life take place. |
| Function of ribosomes | Where protein synthesis takes place. All proteins needed for cell are made here from amino acids. |
| Along with all the features an animal cell has, what do all plant and algal cells have? | A cellulose cell wall which strengthens the cell and gives it support. |
| Along with all the features an animal cell has, what do many plant cells also have? | Chloroplasts - contain chlorophyll, which absorbs light energy to make food by photosynthesis. Permanent vacuole - Filled with cell sap to keep cells rigid to support the plant. |
| What adaptation speeds up diffusion? | Folding up the membrane of a cell or the tissue lining an organ to increase the SA. |
| What happens in the small intestine? | Amylase breaks down starch into sugars Soluble food molecules are absorbed into your blood and get transported in the bloodstream. |
| What happens in the gut? | The muscular walls squeeze undigested food onwards into large intestine. Mixes food with digestive juices. |
| What happens in the large intestine? | Water is absorbed from undigested food into your blood. |
| What are plant organs? | Leaves, stems and roots. |
| Parts of a bacterial cell | Cell membrane Slime capsule Cell Wall Plasmids - Small circular bits of DNA that carry extra genetic information. Flagella - Long protein strands that lash about so bacteria can move around. Genetic material - found free in cytoplasm - unusual. Cytoplasm |
| Parts of a yeast cell | Nucleus Cell wall Cell membrane Cytoplasm |
| What can proteins act as? | Structural components such as muscles and tendons Hormones such as insulin Antibodies, which destroy pathogens. Catalysts in the form of enzymes. |
| What is a protein? | Protein molecules are made up of long chains of amino acids. |
| What are enzymes? | large protein molecules |
| What are enzymes involved in? | 1. Building large molecules from lots of smaller ones (e.g. proteins from amino acids) 2. Changing one molecule --> another (e.g. glucose into fructose) 3. BREAKING DOWN LARGE MOLECULES into smaller ones (e.g. insoluble food molecules --> small soluble molecules like glucose) |
| How do enzymes work? | The long chains of amino acids fold to produce a molecule with a specific shape that allows substrates to fit into the enzyme protein. |
| Effect of pH on enzyme action | Change in pH affects the forces that hold the folded chains in place, so changes shape in molecule. Active site is lost. |
| Why do foods need to be digested? | So they can form smaller, soluble molecules that can be absorbed and used by your cells. |
| Digesting carbohydrates | What breaks it down? Amylase Where is amylase produced? Mouth, small intestine, pancreas. Where is it broken down? Mouth and small intestine. What is it broken down into? Sugars |
| Digesting proteins | What breaks it down? Protease Where is protease produced? Stomach, pancreas and small intestine Where is it broken down? Stomach and small intestine What is it broken down into? Amino acids |
| Digesting fats | What breaks it down? Lipase Where is lipase made? Pancreas and small intestine Where is it broken down? Small intestine What is it broken down into? Fatty acids and glycerol |
| Reasons for respiration | 1. Build up large molecules from smaller ones to make new cell material e.g. sugars, nitrates, other nutrients built up into amino acids into proteins. 2. So muscles can contract - so animals can move. 3. Keep bodies at a constant temperature. |
| The effect of exercise on your body | 1. Heart rate increases and arteries supplying blood to your muscles widen. Increases supply of oxygen + glucose to muscles. 2. Increases rate of CO2 and lactic acid being removed from body. 3. Breathing rate increases, more oxygen brought into your body and picked up by red blood cells. 4. |
| What is anaerobic respiration? | Respiration without oxygen. Glucose is incompletely broken down to form lactic acid. |
| What is the oxygen debt? | The amount of oxygen needed to break down the lactic acid to CO2 and water. |
| Why does sexual reproduction lead to new varieties of plant? | Gametes join. Mixing of DNA. One copy of each gene comes from each parent. |
| What is a cell? | The basic building block of a living organism. |
| What is a nucleus? | The part of the cell that contains genetic info. |
| What is a chromosome? | A thread-like structure holding genes. |
| What is DNA? | Chemical from which all chromosomes are made. |
| What is a gene? | A short section of DNA controlling a characteristic. |
| What is an allele? | A different version of the same gene. |
| What is a dominant allele? | Can be inherited even when other genes are present. |
| What is a recessive allele? | Won't be inherited if other allele is present. |
| What is mitosis needed for? | Growth, repair, replacement and asexual reproduction. |
| Arguments for using stem cells | Offers 1 of the best chances of finding treatments for conditions. Generally uses spare embryos from infertility treatments that would be destroyed anyway. Embryos created from adult stem cells would never become babies. Could use stem cells from umbilical cord blood of newborn babies. |
| Arguments against using stem cells. | May cause further problems e.g. development of cancers. Unethical - embryos can't give permission to be used in experiments/treatments. |
| Who was Mendel? | Carried out breeding experiments using peas. First person to suggest separately inherited factors (now called genes). Found that characteristics were inherited in clear+predictable patterns. |
| Why weren't Mendel's theories accepted? | No-one knew about genes or chromosomes, hadn't seen them through a microscope yet. Insufficient evidence. |
| What is DNA made up of? | Combos of 4 different chemical bases grouped into 3s. Each group of 3 bases codes for a particular amino acid. Order of bases controls order of amino acids so controls which protein is made. |
| Homozygous | An individual with 2 identical alleles for a particular characteristic e.g. DD, dd |
| Heterozygous | An individual with different alleles for a characteristic e,g, Dd |
| Genotype | Describes genetic makeup of an individual regarding a particular characteristic e,g, Dd, dd |
| Phenotype | Describes physical appearance of an individual regarding a particular characteristic e,g, dimples, no dimples. |
| What is polydactyly? Dominant or recessive? | Born with extra fingers or toes. Caused by dominant allele so can be inherited from only 1 parent. |
| What is Cystic Fibrosis? Dominant or Recessive? | Organs become clogged up by thick, sticky mucus which stops them from working properly. Reproductive system's affected - infertile. Caused by recessive allele. |
| Arguments for screening embryos | Gives parents a choice on whether or not to keep the baby. Reduces number of people with CF in population. Cures 'disfigurement' (polydactyly) Reduces health care costs |
| Arguments against screening embrys | Not worth it - polydactyly isn't life-threatening. Could cause miscarriage/damage embryo. |
| Way that fossils can be formed: Hard parts | Bits that don't decay easily (bones, teeth, claws, shells) form fossils. |
| Ways that fossils can be formed: Lack of decay | Conditions needed aren't present e.g. 1. Little/no oxygen present 2. Bacteria that causes decay killed off by poisonous gases. 3. Temperature's too low so organisms are preserved in ice. |
| Ways that fossils can be formed: Replacement | Harder parts of animal/plant replaced by other minerals over a long period of time. |
| Ways that fossils can be formed: Trace fossils | Fossil footprints, burrows, rootlet traces and droppings are formed. |
| Why oh why is the fossil record incomplete? | 1. Early life forms were soft-bodied so left little fossil trace. 2. Most dead organisms didn't become fossilised because right conditions for fossil formation were rare. 3. Geological activity destroyed many fossils. |
| causes of extinction | Changes to environment New predators that wipe out unsuspecting prey that don't have adaptations to avoid them. New diseases. |
| How a new species arrives | Populations separated geographically. In isolated population, alleles are selected that increase successful breeding in the new environment. Speciation Natural selection affects them differently. |
| How do fossils provide evidence for the theory of evolution? | They show that things have changed over time. Fossils have similar features to present-day species. |
| Definition of extinct | All members of a species have died out. |
| What is a species? | A group of organisms that can breed together successfully. |
| Why does the stomach produce hydrochloric acid? | 1. Enzymes of the stomach work best in acidic conditions. 2. It kills most of the bacteria that you take in with your food. |
| What does bile do? | 1. Stored in gall bladder until it's needed. 2. Neutralises acid from the stomach on the food that's come into the small intestine from the stomach. 3. Emuslifies fats, creating much bigger SA for lipase enzymes to work on. |
| How are red blood cells adapted to their function? | 1. No nucleus - more space to carry oxygen to cells. 2. Thin outer membrane - so oxygen can diffuse through easily. 3. Special shape gives it a larger surface area so it can carry more oxygen. |
| Sampling Along a Transect | 1. Take tape measure/marked rope or string 2. Place quadrat 3. Record the presence of each plant type. 4. Place quadrat at next point (regular intervals) 5. Repeat 3 or more times. |
Want to create your own Flashcards for free with GoConqr? Learn more.