Unit 4 NotesKingdom Plantae Plant Characteristics Eukaryotic Plant Cells Heredity and Genetics Future Technology
Kingdom Plantae • Complex, multi-cellular autotrophs (producers)
Kingdom Plantae • Use photosynthesis to make their own food
Kingdom Plantae • Have a cell wall, chloroplast and large vacuole that animals cells do not have
Kingdom Plantae • Eukaryotic
Kingdom Plantae Reproduce Asexually: Rhizomes, tubers, runners & plantlets Reproduce Sexually: Requires female and male sex cells
Plants role in an Ecosystem Plants are producers – they are the first biotic factor in all land-based food chains sun plant worm turtle eagle (abiotic) (biotic) (biotic) (biotic) (biotic)
Plants make and store energy through photosynthesis – they take in water and carbon dioxide and in the presence of sunlight make sugar/glucose and oxygen.
Plants also release energy through cellular respiration. The sugar/glucose and oxygen go in to their mitochondria which turns these products into ATP (energy); water and carbon dioxide are released in this process
Plant Basics Plants have adapted to living on land – they live everywhere on earth – from the icy arctic to the tropics to deserts…
Plant Basics Plants are complex multi-cellular organisms that are organized into the following: • Cells (plant cell) • Tissues (vascular tissue) • Organs (leaf) • Organ systems (shoot system) • Organism (rose bush)
Cell Cell is the basic unit of life – the building blocks of complex, multi-cellular organisms
Tissue A group of similar cells working together to do the same job
Organs Similar tissue working together to do the same job
Organ Systems Groups of similar organs all working together to do the same job
Organism A living thing capable of surviving on its own – made up of two or more organ systems working together
Plant Basics Humans depend on plants for survival: they are a source of food; they provide us oxygen; and we get natural gas, coal and soil from them.
Plant Cells are Eukaryotic Plant cells have the following organelles and they do the following jobs: • Nucleus (controls all activities / DNA) • Mitochondria (cellular respiration / energy) • Ribosomes (makes proteins) • Lysosomes (cleans waste) • Cell membrane (allows diffusion & osmosis) • Cell wall (strength and support) • Chloroplasts (photosynthesis) • Large vacuoles (storage of water & minerals)
Heredity and Genetics Gregor Mendel studied thousands of pea plants to up with the basic principles of heredity that we still use today
Heredity and Genetics These principles all start with sexual reproduction – where two prents combine sex cells (each with ½ of their DNA) to create new organisms - now with a combination of traits from each parent
Heredity and Genetics Chromosomes are coiled pieces of DNA and protein that carry genes (which code for a specific trait). Each form of a gene is called an allele. Alleles can be dominant or recessive.
Heredity and Genetics Dominant alleles will always present – or show (RR or Rr), while a recessive trait will only show itself if two recessive alleles are present (rr).
Heredity and Genetics An organism’s geneotype is represented by the letters – RR, Rr, or rr. The phenotype for these genotypes is either round or wrinkled.
Heredity and Genetics • Reginald Punnett developed a tool called the Punnett Square – it is a way to predict all of the possible genotypes offspring could have. • Each box in the Punnett Square shows a way the alleles from each parent could combine in potential offspring.
Plant Cell Division Plants are complex organisms that grow throughout their lifetime. Cells inside these organisms divide in two ways for two different purposes
Plant Cell Division In order to make new body cells (somatic) cells – plant cells undergo mitosis. In this process the nucleus divides and forms two new identical cells.
Plant Cell Division In order to make new sex cells (gametes) – plant cells go through meiosis. In this process the nucelus divides twice and you end up with 4 new cells – each with only ½ of the genetic material as the parent cell.
Modern Technology and Plants Selective breeding has allowed farmers to select and breed two parent plants to produce offspring with the traits they choose. Examples include sweeter corn, bigger tomatoes and round peas.
Modern Technology and Plants Genetic engineering has allowed farmers to get the traits they want, this time by taking a section of DNA from one organism and inserting it into another organism Example: glow in the dark tobacco plant
Modern Technology and Plants While the benefits to these two processes seem obvious – some scientists worry that unforseen problems might arise – what if a genetically altered plant accidently crossbreeds with something harmful (like a weed) and a super strain of weeds takes over?
Plants and Evolution Some scientists think that modern plants evolved from ancient plant-like protists. These same scientists think that plant-like protists evolved from ancient cyanobacteria and archaebacteria.