Term
| when does the cell cycle start? |
|
Definition
| when a cell has been produced by cell division |
|
|
Term
| when does the cell cycle end? |
|
Definition
| when the cell divides to produce to identicalcells |
|
|
Term
| what 2 stages does the cell cycle consist of? |
|
Definition
|
|
Term
|
Definition
| a period of cell growth and DNA replication |
|
|
Term
| what 2 things does the M phase involve? |
|
Definition
| mitosis (nuclear division) and cytokinesis (cytoplasmic division) |
|
|
Term
| how many separate growth phases is the interphase divided into? |
|
Definition
|
|
Term
| name the 3 growth phases in interphase? |
|
Definition
|
|
Term
| the cell cycle is regulated by checkpoints. name 2 jobs of the checkpoints |
|
Definition
| 1. prevents uncontrolled divisions (cancer) 2. detects and repairs damage to DNA |
|
|
Term
| draw the interphase cell cycle diagram |
|
Definition
|
|
Term
| name 5 events that occur within the cell in the Gap 1 phase |
|
Definition
| 1. cells grow 2. transcription of genes to make RNA 3. organelles duplicate 4. biosynthesis 5. the p53 genes help to control this phase |
|
|
Term
| where is the checkpoint in the the Gap 1 phase? what does this ensure? |
|
Definition
| at the G1 / S restriction point - ready for S phase |
|
|
Term
| name 1 event that occurs within the cell in Gap 0 phase |
|
Definition
| 1. cells may undergo APOPTOSIS, DIFFERENTIATION OF SENESCENCE |
|
|
Term
| where is the checkpoint in the Gap 0 phase? |
|
Definition
| at the early G1 restriction point |
|
|
Term
| name 2 events that occur within the cell in Synthesis phase |
|
Definition
| 1. DNA replicates 2. Chromosomes are duplicated = each has an identical sister CHROMATID |
|
|
Term
| there are no checkpoints in the Synthesis phase. but what is there instead in order to control the process? |
|
Definition
| there is a specific order to the replication of genes = genes activated in all cells are replicated first and genes which are inactive in some cells are replicated last |
|
|
Term
| name 2 events that occur within the cell in Gap 2 phase |
|
Definition
| 1. cells grows 2. proteins needed for mitosis division are made |
|
|
Term
| where is the checkpoint in the Gap 2 phase? what does this ensure? |
|
Definition
| at the G2 / M restriction = ensures cell is ready for mitosis = stimulates proteins that will be involved in making chromosomes condense |
|
|
Term
| name 2 events that occur within the cell in M phase |
|
Definition
| 1. cell growth stops 2. mitosis and cytokinesis occur |
|
|
Term
| where is the checkpoint for M phase? what does this ensure? |
|
Definition
| half way through the M phase = ensures the cell is ready to complete mitosis |
|
|
Term
|
Definition
| a type of nuclear division that maintains the chromosome's number, producing genetically identical daughter cells |
|
|
Term
| what is the significance of mitosis in the life cycle? give 3 points |
|
Definition
| 1. asexual reproduction e.g. amoeba 2. growth 3. tissue repair e.g. division of white blood cells |
|
|
Term
| name the 6 stages in mitosis |
|
Definition
| 1. interphase 2. prophase 3. metaphase 4. anaphase 5. telophase 6. cytokinesis |
|
|
Term
| briefly explain what happens in the interphase |
|
Definition
|
|
Term
| explain what happens in the prophase |
|
Definition
| 1. chromosomes condense = shorter & fatter 2. nuclear envelope breaks down 3. note that because the chromosomes duplicated in the S phase they are now sister chromatids held together by centromeres 4. centrioles move to the opposite polls of the cell |
|
|
Term
| explain what happens in the metaphase |
|
Definition
| 1. chromosomes line up along the spindle thread/tubulin thread equator created by the centrioles 2. they attach by their centromeres 3. at the metaphase checkpoint they check that all of the centromeres are attached properly |
|
|
Term
| explain what happens in the anaphase |
|
Definition
| 1. centromere of each pair of chromatids splits 2. motor proteins, walking along the tubulin thread, pull each sister chromatid in a opposite direction towards opposite poles 3. the chromatids now become known as chromosomes 4. they become v-shaped |
|
|
Term
| explain what happens in the telophase |
|
Definition
| 1. the separated chromosomes reach the poles 2. new nuclear envelopes form around each set of chromosomes 3. cell now contains 2 nuclei, each genetically identical to each other and the parent |
|
|
Term
|
Definition
| the division of the cytoplasm after mitosis |
|
|
Term
| explain what happens in cytokinesis in animal cells |
|
Definition
| a cleavage furrow forms to divide the cytoplasm |
|
|
Term
| explain what happens in cytokinesis in plant cells |
|
Definition
| an end plate forms and the new plasma membrane is laid down on it |
|
|
Term
| what exactly does mitosis produce? |
|
Definition
| 2 genetically identical daughter cells |
|
|
Term
|
Definition
| stain cells and view under microscope |
|
|
Term
|
Definition
| a type of nuclear division that results in the formation of cells containing half the number of chromosomes of the parent cell |
|
|
Term
| what types of gametes must meiosis form? |
|
Definition
|
|
Term
|
Definition
| having only one set of chromosomes |
|
|
Term
| where does meiosis occur? |
|
Definition
| in diploid germ cells to produce haploid gametes. this all occurs in specialised organs called GONADS i.e. ovaries& testes |
|
|
Term
| define homologous chromosomes |
|
Definition
| matching chromosomes, one maternal and one paternal, containing the same genes in the same loci. they may contain different alleles for some genes |
|
|
Term
| name the 9 stages of meiosis |
|
Definition
| 1. interphase 2. prophase 1 3. metaphase 1 4. anaphase 1 5. telophase 1 6. prophase 2 7. metaphase 2 8. anaphase 2 9. telophase 2 |
|
|
Term
| name 5 events that occur in prophase 1 |
|
Definition
| 1. chromatin condenses & each chromosome supercoils 2. nuclear envelope breaks down 3. centriole moves to opposite poles of cell 4. chromosomes come together in their homologous pairs 5. crossing over occurs where non-sister chromatids wrap around each other and swap sections so that alleles are shuffled - the point where they cross is called the CHIASMA |
|
|
Term
| name 1 event that occurs in the metaphase 1 |
|
Definition
| the pairs of crossed over homologous chromosomes attach to the spindle thread equator by their centromeres. note that they join at right angles to the direction of lining up in mitosis |
|
|
Term
| name 4 events that occur in anaphase 1 |
|
Definition
| 1. homologous chromosomes move to opposite poles by motor proteins 2. the centromeres do not divide 3. each chromosome consists of 2 chromatids 4. cross over areas separate from each other = allele shuffling |
|
|
Term
| name 2 events that occur in telophase 1 |
|
Definition
| 1. 2 nuclear envelopes form around pole 2. cell divides by cytokinesis |
|
|
Term
| how many centromeres are there in each cell after meiosis one? |
|
Definition
|
|
Term
| are the cells produced in meiosis 1 haploid or diploid? |
|
Definition
| diploid (have more than one set of chromosomes) |
|
|
Term
| describe the contents of the cell's nucleus after meiosis 1 |
|
Definition
| each nucleus contains half the original number of chromosomes, but each chromosome consists of 2 chromatids |
|
|
Term
| explain 2 events that occur in prophase 2 |
|
Definition
| 1. newly formed nucleus breaks down 2. centrioles replicate and move to poles |
|
|
Term
| explain 1 event that occurs in metaphase 2 |
|
Definition
| chromosomes attach to spindle equator by centromeres |
|
|
Term
| explain 2 events that occur in anaphase 2 |
|
Definition
| 1. cetromeres divide 2. chromatids of each chromosome are pulled apart by motor proteins = chromosomes are now randomly segregated |
|
|
Term
| explain 1 event that occurs in telophase 2 |
|
Definition
| nuclear envelopes form around each of the new nuclei |
|
|
Term
| how many and what type of cells are formed from meiosis 2? |
|
Definition
|
|
Term
| name 4 ways meiosis produces genetic variation |
|
Definition
| 1. crossing over during prophase 1 = shuffles alleles 2. independent assortment of chromosomes in anaphase 1 = random distribution of maternal & paternal chromosomes of each pair 3. independent assortment of chromatids in anaphase 2 leads to further random distribution of genetic material 4. haploid gametes are produced which can go on to fuse with other random gametes |
|
|
Term
| name one thing organisms require |
|
Definition
|
|
Term
|
Definition
| the process by which stem cells become specialised into different types of cells |
|
|
Term
|
Definition
| an unspecialised cell able to express all of its genes and divide by mitosis e.g. a zygote |
|
|
Term
| name 2 reasons why embryonic stem cells differentiate |
|
Definition
| 1. to change the shape of the cell 2. to change the contents of the cell |
|
|
Term
| due to differentiation, each cell type is specialised for... |
|
Definition
|
|
Term
| name 4 examples of specialised animal cells |
|
Definition
| erythrocytes, neutrophils, spermatooza, epithelial cells |
|
|
Term
| what is the function of erthrocytes? |
|
Definition
| to carry oxygen in the blood, from lungs to cells |
|
|
Term
| name 4 adaptations of erythrocytes |
|
Definition
| 1. bioconcave disc shape = high SA 2. no nucleus = more room for haemoglobin 3. flexible due to well developed cytoskeleton and small (7nm) = moves through capillaries |
|
|
Term
| what is the function of neutrophils? |
|
Definition
| to ingest invading pathogens, by phagocytosis |
|
|
Term
| name 5 adaptations of neutrophils |
|
Definition
| 1. many lysosomes in their cytoplasm 2. flexible 3. twice the size of erythrocytes 4. multilobed nucleus 5. attracted towards infection by chemotaxis |
|
|
Term
| what is the function of spermatozoa? |
|
Definition
|
|
Term
| name 4 adaptations of spermatozoa |
|
Definition
| 1. flagellum, long and thin= can swim 2. many mitochondria = energy 3. the acrosome contains digestive enzymes = can penetrate egg |
|
|
Term
| what is the function of epithelial cells? |
|
Definition
| to line the organs/capillaries to make them smooth (a lining tissue) |
|
|
Term
| name 2 adaptations of epithelial cells |
|
Definition
| 1. squamous epithelium are flat = efficient diffusion of gas 2. ciliated epithelium have cilia which beat rhythmically to clear airways |
|
|
Term
| name 5 specialised plant cells |
|
Definition
| palisade mesophyll cells, guard cells, root hair cells, xylem, phloem |
|
|
Term
| what is the function of palisade mesophyll cells? |
|
Definition
|
|
Term
| name 4 adaptations of palisade mesophyll cells |
|
Definition
| 1. contain many chloroplasts 2. large vacuole = chloroplasts are positioned at edge of cell = decreases diffusion distance 3. have cytoskeleton threads and motor proteins = can move chloroplasts to higher levels of light 4. long and cylindrical = pack closely = CO2 can easily diffuse into cell |
|
|
Term
| what is the function of guard cells? |
|
Definition
| allows gas exchange for photosynthesis |
|
|
Term
| explain how guard cells work? |
|
Definition
| 1. in light they fill with water = turgid = thin outer walls and thick inner walls force them to bend = opens stomata = allows gas exchange 2. shuts at night by losing water |
|
|
Term
| name the function of root hair cells |
|
Definition
| to absorb water and mineral ions from soil |
|
|
Term
| name 3 adaptations of root hair cells |
|
Definition
| 1. large SA 2. thin permeable cell wall with special carrier proteins 3. lots of mitochondria |
|
|
Term
|
Definition
| cells in leaves that surround the stomata |
|
|
Term
|
Definition
| closely-packed photosynthetic cells within leaves |
|
|
Term
|
Definition
| epidermal cells of young roots with long hair-like projections |
|
|
Term
|
Definition
| a group of cells that work together to perform (a) specific function(s) |
|
|
Term
| name 4 main animal tissue types |
|
Definition
| 1. epithelial tissue 2. connective tissue 3. muscle tissue 4. nervous tissue |
|
|
Term
| what is the job of epithelial tissue? |
|
Definition
| it lines and covers free surfaces |
|
|
Term
| what type of tissue is epithelial tissue? |
|
Definition
|
|
Term
| what is epithelial tissue formed by? |
|
Definition
| closely packed, continuous cells (1 cell thick) |
|
|
Term
| name the 2 types of epithelial tissue |
|
Definition
| 1. squamous epithelium 2. ciliated epithelium |
|
|
Term
| name 3 properties of squamous epithelium |
|
Definition
|
|
Term
| what is squamous epithelium held in place by? |
|
Definition
| a network of collagen and glycoproteins |
|
|
Term
| name 2 properties of ciliated epithelium |
|
Definition
|
|
Term
| where is ciliated epithelium found? |
|
Definition
|
|
Term
| what can be found between ciliated epithelial cells? |
|
Definition
|
|
Term
| what is the purpose of the cilia? |
|
Definition
| to move rhythmically and move away mucus produced by goblet cells |
|
|
Term
| what is the job of connective tissue? |
|
Definition
| to hold structure together and provide support |
|
|
Term
| what is connective tissue made up of? |
|
Definition
| extracellular matrix containing proteins and polysaccharides |
|
|
Term
| name one example of connective tissue |
|
Definition
|
|
Term
|
Definition
| immature cells in cartilage |
|
|
Term
| when chondroblasts divide by mitosis what do they secrete? |
|
Definition
|
|
Term
| what are mature cells in cartilage called? |
|
Definition
|
|
Term
| name the 3 types of cartilage |
|
Definition
| 1. hyaline 2. elastic 3. fibrous |
|
|
Term
| name 2 jobs of hyaline cartilage |
|
Definition
| 1. covers ends of long bones 2. joins ribs to sternum |
|
|
Term
| what does hyaline cartilage form from? |
|
Definition
|
|
Term
| name 2 places where hyaline cartilage can be found |
|
Definition
|
|
Term
| what does elastic cartilage have more of than hyaline cartilage? |
|
Definition
|
|
Term
| name one thing that elastic cartilage makes up |
|
Definition
|
|
Term
| name 2 places where fibrous cartilage found? |
|
Definition
| in discs between vertebrae, knee joints |
|
|
Term
| besides chondrocytes and matrix, what else makes up fibrous cartilage? |
|
Definition
|
|
Term
| what is the job of muscle tissue? |
|
Definition
| to contract and cause movement |
|
|
Term
| name 3 adaptations of muscle tissue |
|
Definition
| 1. many blood vessels 2. elongated 3. contains myofilaments = allows contraction |
|
|
Term
| name the three types of muscle tissue |
|
Definition
| 1. skeletal muscles 2. cardiac muscle 3. smooth muscle |
|
|
Term
| what is the job of skeletal muscle? |
|
Definition
|
|
Term
| what is skeletal muscle joined to, and by what? |
|
Definition
| joined to bones by tendons |
|
|
Term
| what is the job of cardiac muscle? |
|
Definition
| to make up walls of heart = can beat |
|
|
Term
| name 4 places where smooth muscle is found? |
|
Definition
| walls of intestine, blood vessels, uterus, urinary tracts |
|
|
Term
|
Definition
| 1. epidermal tissue 2. vascular tissue 3. meristematic tissue |
|
|
Term
| what is epidermal tissue equivalent to? |
|
Definition
| epithelial tissue in animals |
|
|
Term
| what is epidermal tissue formed of? |
|
Definition
|
|
Term
| what is the job of epidermal tissue? |
|
Definition
| to form a protective covering over leaves (a cuticle) to prevent water loss |
|
|
Term
| name 2 types of vascular tissue |
|
Definition
|
|
Term
| what is the job of xylem? |
|
Definition
| to carry water and minerals from roots to plant |
|
|
Term
| name 4 structural points about xylem |
|
Definition
| 1. made of dead cells 2. thick cell wall made of lignin 3. no cytoplasm 4. has fibres |
|
|
Term
| what is the job of phloem? |
|
Definition
| phloem sieve tubes transfer products of photosynthesis from leaves to parts of plants, such as flowers, roots and shoots |
|
|
Term
| what does meristematic tissue contain? |
|
Definition
|
|
Term
| name 5 properties of the cells found within meristematic tissue |
|
Definition
| 1. thin walls (little cellulose) 2. no chloroplasts 3. small vacuole 4. divide by mitosis 5. can differentiate into other cells |
|
|
Term
|
Definition
| a collection of tissue working together to perform a specific function |
|
|
Term
|
Definition
| a number of organs working together to carry out an overall life function |
|
|
Term
|
Definition
| 1. leaf 2. root 3. stem 4. flower |
|
|
Term
| what is the function of a leaf? |
|
Definition
|
|
Term
| name 3 functions of a root |
|
Definition
| 1. anchorage to soil 2. absorption of mineral ions and water 3. storage |
|
|
Term
| name 4 functions of the stem |
|
Definition
| 1. support 2. holds up plant to light 3. transportation 4. storage |
|
|
Term
| what is the function of a flower? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| name 11 animal organ systems |
|
Definition
| 1. digestive system 2. circulatory 3. respiratory 4. urinary 5. integumentary 6. musculo-skeletal 6. immune 7. nervous 8. endocrine 9. reproductive 10. lymph |
|
|
Term
| which organs/tissues are involved in the digestive system? |
|
Definition
| oesophagus, stomach, intestines, liver, pancreas |
|
|
Term
| which organs/tissues are involved in the circulatory system? |
|
Definition
|
|
Term
| which organs/tissues are involved in the respiratory system? |
|
Definition
| airways, lungs, diaphragm, intercostal muscles |
|
|
Term
| which organs/tissues are involved in the urinary system? |
|
Definition
| kidneys, ureters, bladder |
|
|
Term
| which organs/tissues are involved in the integumentary system? |
|
Definition
|
|
Term
| which organs/tissues are involved in the immune system? |
|
Definition
| bone marrow, thymus gland, skin, stomach acid, blood |
|
|
Term
| which organs/tissues are involved in the nervous system? |
|
Definition
| brain, spinal chord, nerves |
|
|
Term
| which organs/tissues are involved in the endocrine system? |
|
Definition
| glands that make hormones e.g. testes |
|
|
Term
| which organs/tissues are involved in the reproductive system? |
|
Definition
| testes, penis, ovaries, uterus, vagina |
|
|
Term
| which organs/tissues are involved in the lymph system? |
|
Definition
|
|
Term
| give examples of the functions of the digestive system |
|
Definition
| nutrition to provide ATP and materials for growth and repair |
|
|
Term
| give examples of the functions of the circulatory system |
|
Definition
| transport to and from cells |
|
|
Term
| give examples of the functions of the respiratory system |
|
Definition
| breathing and gaseous exchange, excretion |
|
|
Term
| give examples of the functions of the urinary system |
|
Definition
| excretion, osmoregulation |
|
|
Term
| give examples of the functions of the integumentary system |
|
Definition
| waterproofing, protection, temperature regulation |
|
|
Term
| give examples of the functions of the musculo-skeletal system |
|
Definition
| support, protection, movement |
|
|
Term
| give examples of the functions of the immune system |
|
Definition
| protection against pathogens |
|
|
Term
| give examples of the functions of the nervous system |
|
Definition
| communication, control, coordination |
|
|
Term
| give examples of the functions of the endocrine system |
|
Definition
| communication, control, coordination |
|
|
Term
| give examples of the functions of the reproductive system |
|
Definition
|
|
Term
| give examples of the functions of the lymph system |
|
Definition
| transports fluids back to the circulatory system and is also important in resisting infection |
|
|
Term
|
Definition
| unspecialised cell able to express all of its genes and divide by mitosis |
|
|
Term
| name 4 characteristics of stem cells |
|
Definition
| 1. undifferentiated 2. pluripotent 3. able to express all their genes 4. can divide by mitosis = provides more cells that can divide into specialised cells |
|
|
Term
| name 4 sources of stem cells |
|
Definition
| 1. embryonic stem cells 2. stem cells in umbilical-cord blood 3. adult stem cells (e.g. in blood, brain, muscle, bone) 4. induced pluripotent stem cells developed in labs (iPS cells) |
|
|
Term
| what does pluripotent mean? |
|
Definition
| able to make any cells possible |
|
|
Term
| name 4 potential uses of stem cells in research and medicine |
|
Definition
| 1. bone-marrow transplants 2. drug research 3. developmental biology 4. repair of damaged tissues or replacement of lost tissues |
|
|
Term
| name an illness that bone-marrow transplants are used to treat |
|
Definition
|
|
Term
| why could stem cells be useful for drug research? |
|
Definition
| new drugs can be tested on them instead of humans |
|
|
Term
| define regenerative medicine |
|
Definition
| methods to replace or regenerate human cells, tissues or organs in order to restore or establish normal function |
|
|
Term
| name two things that stem cells may able to treat/cure in the future |
|
Definition
| diabetes, Alzheimers disease |
|
|
