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60 Cards in this Set
- Front
- Back
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What is in animal cells? |
Nucleus - genetic material Cytoplasm - chemical reactions occur here Cell membrane - controls what goes in + out Mitochondria - respiration Ribosome - protein synthesis |
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What is in plant cells? |
Cell wall - supports + strengthens Permanent vacuole - filled w/ cell sap Chloroplasts - Absorb light, photosynthesis |
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What is in yeast and bacteria? |
Yeast - single celled, has a nucleus, cytoplasm, cell membrane and cell wall. Bacteria - single celled, has cell membrane, cell wall and genetic material. |
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What is diffusion? |
Spreading out of particles from an area of high to an area of low concentration Happens in solutions + gases Bigger concentration difference = faster diffusion rate |
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What happens in cell membranes with diffusion? |
Dissolved solutions can move in + out of cells by diffusion. Only small molecules can diffuse (oxygen, glucose, amino acids, water) Big molecules don't (starch + protein) |
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What are the adaptations of palisade leaf cells? |
Chloroplasts at top of cell, tall = larger surface area at the side, thin = more into a leaf |
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What are the adaptations of guard cells? |
Open + close stomata in leaf, plant has lots of water = cells fill with water + stomata open, plant has little water = stomata close. Thin outer walles + thick inner walls. Light sensitive (close at night) |
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What are the adaptations of red blood cells? |
Concave = bigger surface area, lots of haemoglobin, no nucleus (more room) |
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What are the adaptations of the gametes? |
Egg cell - Has good reserves Sperm - long tail, streamline head, lots of mitochondria, enzymes in head to digest egg cell |
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What is differentiation? |
Cells become specialised, during development of multicellular organism. For tissues, then organs then organ systems. |
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What is a tissue? |
Group of similar cells which perform a function. Muscular - contracts Glandular - Makes + secretes enzymes + hormones Epithelial - covers parts of the body |
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What is an organ? |
Groups of different tissues that work together to perform a function, the stomach has: Muscular tissue: churn up food, glandular: makes digestive juices, epithelial: covers stomach |
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What is an organ system? |
Group of organs working to perform a function (digestive system) Glands - Make digestive juices, stomach + small intestine - digest food Liver - Makes bile, small intestine - absorbs food, large intestine - absorbs water |
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What are the organs and tissues in plant cells? |
Organs - Stems, roots, leaves Tissues - Mesophyll (photosynthesis) Xylem + phloem (transport water, mineral + vitamins) Epidermal (covers plant) |
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What is the photosynthesis equation? |
Carbon dioxide + water -(sunlight)-> glucose + oxygen |
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What are the limiting factors of photosynthesis? |
Light - Moving lamp, measure light intensity CO2 - Dissolve amounts of sodium hydrogencarbonate Temperature - Control with water bath |
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What is the limiting factors experiment? |
Pondweed in tube + measure amount of oxygen given off |
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What are the ways you can control things in a greenhouse? |
Temperature - Heater, shades, ventilation Light - Artificial lights CO2 - Paraffin heater Stops pests, disease, you can add fertiliser` |
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What is glucose used for? |
Respiration (growth) Cell walls (converted into cellulose) Proteins (combine w/ nitrate ions to make amino acids) Store in seeds (turn into lipids) Store as starch (insoluble, stored in roots, stems + leaves |
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What is distribution? |
Where the organism is found (part of a habitat) Affected by, temperature, availability of water, oxygen, CO2, nutrients, light Measure 2 different areas and compare, or how distribution changes across area |
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What is the method for using a quadrat? |
Place on ground randomly, count organisms, repeat, work out mean, and compare, |
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How do you work out population size? |
(Average organisms/m^2)*total area |
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What is the method for using a transect line? |
Mark out line, collect data (counting organisms) |
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What is reliability? What is validity? |
Make them repeatable and reproducible (take a large sample size) Reliable + answer question (control all variables), use random samples |
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What are enzymes? |
Speed up reactions without raising temperature, they're biological catalysts (aren't used) They're proteins (chains of amino acids folded into unique shapes) Will only catalyse one reaction, a substance will fit its special shape If it gets too hot the bonds break apart, too high/low pH breaks it too |
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What is amylase? Protease? Lipase? |
A - Starch - > Maltose (salivary glands, pancreas, small intestine) P - Protein -> Amino acid (stomach - called pepsin, pancreas, small intestine) L - Lipids -> Glycerol + fatty acids (Pancreas, small intestine) |
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What is bile? |
Neutralises stomach acid making it alkaline (small intestine works too), emulsifies fats - giving larger surface area. Produced in liver, stored in gall bladder, released in small intestine |
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What is the process in the breakdown of food? |
Salivary glands - Amylase Stomach - Pummels food, produces pepsin + HCL (kill bacteria + creates right pH) Liver - Bile is produced Gall bladder - Bile stored Pancreas - Produces protease, amylase + lipase Small intestine - Produces protease, amylase + lipase, food absorbed Large intestine - Excess water absorbed |
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What is respiration? |
Process of releasing energy from glucose |
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What is anaerobic respiration? |
Uses oxygen, most efficient, go on in plants + animals, happens in mitochondria Glucose + Oxygen -> CO2 + H2O + Energy |
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What does respiration do? |
Build up large molecules from smaller ones, allows muscles to contract, keeps body temperature steady in mammals + birds, plants - build sugars, nitrates into amino acids then into proteins |
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What is exercise? |
Muscles use oxygen to release energy from glucose to contract muscles More activity means more glucose and oxygen, more CO2 must be removed - blood must flow faster Increases breathing rate to get more oxygen, increase speed of heart pumps |
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What is glycogen? |
Stored in liver, in vigorous exercise glycogen is converted to glucose for energy. |
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What is anaerobic respiration? |
Not enough oxygen, incomplete breakdown of glucose Glucose -> energy + lactic acid Lactic acid builds up causing muscle fatigue + doesn't release as much energy |
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What is oxygen debt? |
Causes you to breath hard after you stop to get more oxygen. High levels of CO2 + lactic acid are detected in the blood - pulse + breathing rate stay high |
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What do enzymes do in biological detergents? |
Mostly proteases and lipases, will remove food/blood stains. Are more effective at lower temperatures. |
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What do enzymes do in changing foods? |
Baby foods are pre digested with protease Carbohydrases turn starch syrup into sugar syrup Glucose syrup |
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What do enzymes do in industry? |
Advantage - Specific, low temperatures (saves money), work for a long time, biodegradeable Disadvantage - Allergies, conditions (temp + ph) must be controlled, expensive to produce, contamination can affect reaction |
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What is DNA? What are genes? |
Made of chromosomes? Section of DNA, contains instructions to make a protein with amino acids (depending on order) and determines the proteins the cell produces, which determines the type of cell it is. |
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What is DNA fingerprinting? |
Cutting up DNA then separating them. Everyone's fingerprint is unique (except identical twins). Used in forensic science and paternity testing |
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How many chromosomes in a cell? |
2 copies of each chromosome, total of 23 pairs |
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What is mitosis? |
Cell reproduces by splitting into 2 identical offspring. Duplicates DNA, lines up at centre + cell fibres pull them apart, membranes form around each set of chromosomes (these are the nuclei), then cytoplasm divides Used to grow/replace damaged cells, some animals reproduce this way (cells) |
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What are gametes? |
Sex cells, only one set of chromosomes, when 2 gametes join the cell divides by mitosis. |
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What is meiosis? |
Produces gametes in the ovaries and testes Duplicates DNA, first division (chromosome pairs line up then are pulled apart), second division (arms are pulled apart), 4 gametes with a single set of chromosomes |
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What are embryonic stem cells? |
Differentiation of animal cells is lost at an early stage (Plants don't lose this ability). Stem cells are undifferentiated Found in embryo and bone marrow |
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How are stem cells used in medicine? |
Blood diseases with bone marrow transplants (stem cells -> new blood cells) Scientists can extract stem cells from embryos which could replace heart muscle cells (heart disease), insulin producing cells (diabetes), nerve cells (paralysis) |
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Why are people for and against stem cell research?
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Against - Ending potential life, should find other sources For - People can be cured and most embryos are unwanted anyway |
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What are the different chromosomes people can have to determine their sex? |
XX and XY it's a 50 50 chance |
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What do you need to include in a genetic diagram? |
The parental gametes Derivation of offspring genetics Identification of the percentage changes of having each gene |
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What did gregor mendel do? |
Crossed a tall and dwarf pea plant, got 3 tall plants and 1 dwarf plant Characteristics are determined by hereditary units, one unit is passed from each parent, they can be dominant or recessive |
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What is an allele? What does homozygous and heterozygous mean? What is a phenotype and what is a genotype? |
Different versions of the same gene 2 alleles for one gene the same 2 alleles different Characteristic The alleles you have |
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What is cystic fibrosis? What is polydactyly? |
Mucus in air passages, it's recessive Extra fingers/toes, it's dominant |
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What is in vitro fertilisation? |
Embryo ferilised then place into womb, you can analyse its genes, you can destroy embryos with disorders, |
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Why are people for and against embryo screening? |
For - stops suffering, laws stop it going too far, IVF destroys most babies anyway, treating disorders costs the government a lot of money Against - people might only pick desirable ones, rejected embryos could have become humans, could create prejudice, it's expensive |
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What happens if parents have a homozygous dominant and homzygous recessive gene? Homozygous dominant, heterozygous gene Heterozygous , homozygous recessive |
All heterozygous 2 homozgyous, 2 heterozygous (all with a dominant) 1:1 ratio, all homozygous |
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How are fossils made? |
Gradual mineral replacement - teeth, shells, bones don't decay easily so are replaced by minerals forming a rocks like substance, surrounding sediment turns to rock Casts + impressions - organism dying in sediment leaves a cast, footprints leave impressions Preservation - Amber + tar (no O2/moisture for microbes), glaciers (cold), peat bogs (too acidic) |
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How did life began? |
Maybe primordial soup, maybe comets. But there is a lack of valid + reliable evidence since early organisms were soft-bodied and fossils were destroyed |
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How does extinction occur? |
Envrionment changes too quickly, new predator, new disease, can't compete, catastrophic event, speciation develops |
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How does speciation occur? |
Development of a new species, when populations of the same species become so different they can no longer produce fertile offspring |
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How does isolation occur? |
Population of species are separated, possible physical barrier Conditions on either side are different so different characteristics become common They show variation because of a wide range of alleles They evolve developing a new species |
