Biology Midterm Exam PDF

Questions: 1.​ What is the significance of meiosis to sexual reproduction (reductive division) -meiosis helps create sex cells, it ensures that fertilization happens and the new organism has the correct number of chromosomes, gives genetic variety in offspring 2.​ SEXUAL REPR...

Questions: 1.​ What is the significance of meiosis to sexual reproduction (reductive division) -meiosis helps create sex cells, it ensures that fertilization happens and the new organism has the correct number of chromosomes, gives genetic variety in offspring 2.​ SEXUAL REPRODUCTION:​ -Sexual reproduction creates genetic diversity by mixing genes from both parents. Each parent gives half of their genes to their offspring during this process. Independent assortment randomly shuffles chromosomes, and crossing over swaps parts of chromosomes between parents, creating even more variety. This genetic variation helps species adapt to changes in their environment over time. It creates 4 genetically different haploid daughter cells. 3.​ Why are there so many varied phenotypes within a species such as humans -because of the genetic diversity (genetic mixing, mutations, and environmental influences all contribute) 1.​ What is the basis reason for classifying organisms into taxa (groups) -studying relationships 2.​ Do you think there are more classes or orders of organisms on earth? Explain? -more orders because orders are smaller, more specific groups within each class Biodiversity: 6 kingdoms and their main characteristics: Cell type, organization (uni/multicellular), source of energy/nutrition (auto vs heterotrophic) and one example of a member species (on paper) Differences between Mitosis and Meiosis: Mitosis Meiosis -One cell division -Two cell divisions -DNA replication during interphase -DNA replication during meiosis 1 -results in 2 identical cells per cycle (2 -4 genetically different haploid daughter genetically identical daughter cells) cells -happens in body cells (growth and repair) -happens in reproductive cells -production of gametes and genetic variation in organisms Stem Cells: Stem cells are unspecialized cells that can develop into different cell types in the body under the right conditions. They have no special functions but can do regular things like growing and metabolizing. Each type of stem cell has different potents (multipotent, totipotent, pluripotent) which determines what type of cells it evolves into. Stem cells can be used in people to repair/regenerate damaged tissues from disease or to correct parts of organs that don't work properly etc. When stem cells are taken to do something, their embryos are done after that Embryonic Stem cells are special cells from early-stage embryos that can develop into any type of cell in the body Adult stem cells: cells in the body that can replace or repair damaged issues Pluripotent stem cells: can turn into any type of cell in the body, except for those needed to support a fetus. Multipotent stem cells: can develop into several, but not all, types of cells in the body. Totipotent stem cells: can turn into any type of cell, including those that make a whole organism What is it about the structure of DNA that allows scientists to create transgenic organisms:(mice and bacteria on first page of the DNA slide) DNA's universal structure allows scientists to insert genes from one species into another, creating transgenic organisms. Rules of Mendelian Genetics: Rules of Mendelian Genetics: -why recessive traits often disappear for a generation or two then reappear in other generations: law of dominance -Use of punnett squares OR pair of alleles segregate (separate) from each other during meiosis so only one allele will be present in each gamete: segregation -Genes being located on chromosomes and how tetrads line up and separate OR​ random distribution of alleles during the formation of gamete: independent assortment The inheritance pattern involved when both alleles are expressed in the heterozygote is: codominance The inheritance pattern we studied that affects males and females differently due to the fact that female sex chromosomes are homologous and male sex chromosomes are not is called: sex-linked Inheritance pattern that exists when there are two alleles and in the heterozygote only one of them is expressed in the phenotype - Inheritance pattern involved when the heterozygote expresses one allele and the other is masked: mendelian When one gene influences multiple traits: pleiotropy When the expression of the phenotype of one gene is either activated or suppressed (turned on or off) by a second gene: epistasis When more than one gene influences the expression of a trait: polygenic inheritance The inheritance pattern involved when the heterozygote expresses one allele and the other is masked: mendelian Inheritance pattern where more than 2 possible alleles exist for one genetic trait: multiple alleles Inheritance pattern after midterm: Pleiotropy-single gene influences multiple unrelated phenotypes (cystic fibrosis: build up in lungs/respiratory problems and Marfan syndrome which affects connective tissue) Epistasis-effect and relationship of one gene changing phenotypes/affecting another gene (labradors) Black lab: BE (at least one of each) Yellow lab: ee (both little) Chocolate lab:bb and E Polygenic-more than 1 gene influences traits Graphs are always polygenic (incomplete dominance) How many alleles control it? -genes: half of the bars, if 4 there 2 genes -alleles: the same amount of bars, 4 bars= 4 allele Blood: (Codominance (AB) and mendelian=ABO ABO blood typing has 4 phenotypes and 6 genotypes Pheno: 1A:1B etc. and Geno: 1:IAi, 1:IBIB etc. Prokaryotic vs. Eukaryotic cells Pro: simple, came first, has no membrane-bound organelles Euk: complex, has nucleus and organelles 3 main ideas of cell theory: -all cells come from preexisting cells -all living things are made up of one or more cells -cells are the basic unit of life Viruses: 1.​ Are viruses alive? -no, they rely on a host cell to reproduce as they cannot do it themselves 2.​ What are the two parts of the viral replication cycle? -Lytic cycle: The virus attaches to the host cell, injects DNA or RNA, takes over cell and makes copies of it, they then are put together to form new viruses, and cell bursts to release a new virus to infect other cells -lysogenic cycle: virus hides in host cells DNA, then becomes active later 3.​ What are 4 ways to prevent the transmission of viruses handwashing, vaccinations, condoms, face masks, clean needles NOT ANTIBIOTICS 4.​ Mutations occur when the protein coat and or spike proteins on the coat of a virus change. What is the significance of smallpox? 5.​ Which types of viruses are more dangerous and why? RNA or DNA -RNA, a higher mutation rate, and the ability to evolve quickly, (RNA viruses: covid, flu, spread fast and cause outbreaks. DNA viruses: smallpox or herpes, more stable, evolve slower) 1.​ Mendel's scientific findings (father of genetics) -law of segregation: the use of Punnett squares -law of independent assortment: understanding of genes being located on chromosomes and how tetrads line up and separate -law of dominance: why recessive trait often disappears for a generation of two then reappears in subsequent generations (worked with small sample sizes) Symbiotic relation Mutualism: both benefit (bees and flowers) Commensalism: one benefits while the other is unaffected Parasitism: one organism benefits, other is harmed (humans and mosquitoes) How do vaccines work to provide your body with immunity: -vaccines work by introducing a harmless part of the virus to your body. It triggers your immune system to produce antibodies and remember how to fight it. If you are exposed to the real virus later, your immune system can respond quickly, protecting you from illness. Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species Kahoot multiple choice questions: Which statement best sums up what you have learned about Mendel? -one of the first scientists to discover how the laws of heredity work What is heredity? -passing of traits from parents to offspring Genetic traits are -determined by genes -characteristics passed from parents to offspring Mendel hypothesized gametes have 1 factor per inherited trait; a hypothesis supported by… -the fact that haploid cells are produced by meiosis Chromosomes normally occur as homologous pairs in: -a zygote Mitosis produces -two cells that are genetically identical to the mother cell The DNA is replicated during -synthesis A stem cell that is capable of differentiating into many different types of cells is called -totipotent A tumour that has cancerous cells it is -malignant Cells programmed ability to recognize severe mutations and initiate its own death is called -apoptosis Type of enzymes that edit the cell cycle checking for and correcting errors -CDKs Identical halves of a duplicated parent chromosome are called -sister chromatids The sex of a child is determined by the: -father (x y) What is the basic unit of structures and function in living things? -cell What structure would not be found in a bacterium? -mitochondria Organisms in which kingdoms tend to live in harsh environments where not much else can survive. -archaebacteria From smallest to largest… -virus, bacterial cell, animal cell, plant cell Prokaryotic cells (bacteria) are measured in -micrometres Viruses are measured in -nanometers What scientist was the first to use a simple microscope to observe living microorganisms -antoni van leeuwenhoek Scientists coined the term cells because they reminded him of a tiny room in a monastery -robert hooke Cell theory's main parts -all living things are made of cells -cells are the basic units of structure and function -new cells are produced from existing cells Plants, animals, fungi and protists are made of -eukaryotic cells The large membrane-enclosed structure that contains genetic material in a cell -nucleus All cells have… -cell membrane -DNA What does Jonas Salk have to do with polio -he developed the first effective polio vaccine (1950) What evolved first prokaryotic or eukaryotic -prokaryotic Eukaryotic cells are larger and more complex than prokaryotic cells Bacteria and archaea are examples of -prokaryotic cells What type of cell does not have a nucleus? -prokaryotic What is made of eukaryotic cells and mostly unicellular -Protista Cells from the kingdom have a cellulose cell wall, large water vacuole and chloroplasts -Plantae What organelle controls the cellular activities of all cells -chromatin What is the gel-like fluid in the cell called -cytoplasm What organelle store food, water, waste and old cells part -vacuole What organelle performs photosynthesis (the process of converting light energy into glucose) -chloroplast What cellular structure provides protection and support to plant cells -cell wall At this structure, amino acids are joined in long chains to form proteins as instructed by DNA -ribosome -rizz Functions of the Golgi apparatus are -modifies, packages and prepares proteins and lipids into vesicles Organelle at the site of cellular respiration -mitochondria Organelle breaks down anything the cell doesn't want to keep -lysosome Two main parts of the virus -protein coat -genetic material The period of time when a virus might lay dormant after it has infected a cell is called -lysogenic/latent cycle The bubonic plague, great potato famine, and malaria are caused by viruses (T or F) -false Rhinoviruses cause -colds What happens before meiosis begins -DNA is replicated in the original cell What phase of meiosis does crossing over occur -prophase 1 End result of meiosis -4 genetically different haploid gamete cells How does mitosis differ from meiosis -all cells except reproductive cells divide via mitosis Best term to describe the relationship between each pair of chromosomes lined up at the equator during mitosis -sister chromatids What phase of meiosis are sister chromatids pulled apart -anaphase 2 What phase of meiosis do tetrads line up at the equator -metaphase 1 A cell can go through meiosis over and over again (T or F) -false A cell can go through mitosis over and over again (T or F) -true In meiosis, 1 diploid cell (2n) becomes ___ haploid cells (n) -4 How many genetically different offspring can two parents have -billions During the cell cycle, the DNA is replicated during the ___ of interphase -synthesis phase Cells spend the majority of their life cycles in -g1 of interphase The diploid xme # of strawberries is 14. How many xmes are in an octoploid strawberry cell -56 (8x ___ is caused by mutations to the genes controlling the cell cycle uncontrolled mitosis -cancer The cell appears to have a nucleus and was collected from the La Salle River -protist The first scientist to notice a dark spot within all of the plant cells he looked at under the microscope discovering the nucleus -brown These three scientists disproved spontaneous generation by discovering that cells come from other living things of that same kind -virchow, redi, pasteur The first virus to be successfully eradicated due to a gigantic worldwide vaccination program was -smallpox Tetanus is caused by -a virus The technical term used to indicate the infectiousness of a virus is referred to as the -r not value In 1500 Hernando Cortes wiped out the Aztec empire importing ___ to Mexico -smallpox What are stem cells: Unspecialized cells that can develop into specialized cells when under the right conditions Apoptosis vs necrosis Apoptosis: -​ Programmed cell death occurring in a “healthy” person; normal and helpful -​ Cells going through apoptosis actually shrink, shrivel, and break apart in a controlled process Necrosis:  -​ unprogrammed; abnormal and harmful cell death caused by an unhealthy environment (lack of nutrients) or disease Embryonic Stem cells: After fertilization, the resulting mass of cells divides repeatedly until there are about 100–150 cells. These cells have not become specialized. Adult stem cells: Found in various tissues in the body and might be used to maintain and repair the same kind of tissue What are pluripotent stem cells: Can be any type of cell in the body Multipotent stem cells: Have the ability to differentiate into all cell types within one particular lineage Kingdom Pro or Eu Unicellular or Auto, hetero or Representative multicellular or both organism both Plantae E Multi Auto Cactus Animalia E Multi hetero dog Fungi E Multi Hetero mushroom Protista E Mostly both algae unicellular Eubacteria P Unicellular Both E coli Archaebacteria P Unicellular Both Pyrolobus