BC Science Connections 9 Unit 1: The Continuity Of Life .

2y ago
16 Views
2 Downloads
1.95 MB
41 Pages
Last View : 2m ago
Last Download : 2m ago
Upload by : River Barajas
Transcription

BC Science Connections 9Unit 1: The continuity of life depends on cells beingderived from cells

Topic 1.2: What are different ways thatliving things reproduce asexually? Bacteria reproduce bybinary fission. All eukaryotic cellsreproduce by the cell cycle. Yeasts reproduce bybudding. Moulds reproduce usingspores. Plants have many ways toreproduce asexually.

Concept 1: Bacteria reproduce bybinary fission.Bacteria: Micro-organisms that exist as single prokaryotic cells Reproduce asexually by a process called binary fissionFigure 1.6: Bacteria are in, on, and all around us. Bacteria is used in foodproduction (left) and can cause disease, such as strep throat (right).

Reproduction by Binary FissionBinary fission Type of asexualreproduction A parent cell splits intotwo individual,identical cells(daughter cells) Daughter cells haveidentical geneticinformation (DNA)Figure 1.7: Binary fission

Reproduction by Binary Fission (continued)Figure 1.7: (A) Binaryfission. (B) Many typesof bacteria are found aschains and clusters.

Reproduction by Binary Fission (continued)

Discussion Questions1. What key piece of evidencetells you that bacteriareproduce asexually?

Concept 2: All eukaryotic cells reproduce bythe cell cycle.Functions of eukaryoticcell reproduction: Replace older cells Replace damaged cells Produce new offspringin single-celledorganisms (amoebas)Figure 1.8: A scab forms as some of theremaining skin cells beneath the woundreproduce repeatedly to form a new skin layer toreplace what was scraped away.

Reproduction and the Cell CycleEukaryotic cells reproduce by aseries of events called the cell cycleThe cell cycle has two stages withdifferent events: Growth and development Interphase (replication ofDNA Cell division Mitosis (division of nucleus) Cytokinesis (division ofcytoplasm and cellmembrane)Figure 1.10: The cell cycle.

https://www.youtube.com/watch?v mBq1ULWJp M&t 208s&ab channel AmoebaSisters 1:15-3:11

Chromosomes Elaborations (not in textbook)The karyotype is a complete picture of an individual’schromosomes.These images are both human karyotypes. What do you notice?https://www.mun.ca/biology/scarr/Human llustration/human-karyotype-illustration-263985446

Chromosomes Elaborations (not in textbook)Sisterchromatids Chromosomes come indifferent shapes and sizes. Each chromosome hasone centromere.CentromereChromosome(For this slide, ignore all vocab except what ishighlighted in e-types-and-functions/

Chromosomes Elaborations (not in textbook)DNA is replicated during mosomes-article

Chromosomes Elaborations (not in textbook)DNA is replicated during interphase.Chromatid: a complete (double helix) copy of the DNAsequence that is on one chromosome. Before replication, each chromosome is one chromatid. After replication, each chromosome is made of two sisterchromatids connected by a single centromere.

Chromosomes Elaborations (not in textbook)DNA is replicated during interphase.Chromatid: a complete (double helix) copy of the DNAsequence that is on one chromosome. Before replication, each chromosome is one chromatid. After replication, each chromosome is made of two sisterchromatids connected by a single omosomes-article

Practice: Chromosomes1. How many chromosomes?2. Draw a non-replicated chromosome.3. Draw a replicated chromosome. When does replicationtake e-types-and-functions/

Practice: Chromosomes1. How many chromosomes?64 (2 homologous pairs)82. Draw a non-replicated chromosome.3. Draw a replicated chromosome. When does replicationtake place?During interphase (before ure-types-and-functions/

Chromosomes Elaborations (not in textbook)In organisms that reproducesexually, one set of chromosomes isinherited from each parent.Homologous chromosomes: Pair of chromosomes (one fromeach parent) that are similar inlength, centromere location, andthe locations of genes on them.They may differ in the exactversions of the genes they l

Chromosomes Elaborations (not in textbook)In organisms that reproducesexually, one set of chromosomes isinherited from each parent.Homologous chromosomes: Pair of chromosomes (one fromeach parent) that are similar inlength, centromere location, andthe locations of genes on them.They may differ in the exactversions of the genes they mosomes-397/

Practice: Chromosomes4. Draw homologous chromosomes using the diagrams belowas guides. Label chromatids, sister chromatids, andcentromeres.a)b)5. What is wrong with this picture?6. Sister chromatids and homologous chromosomes are oftenconfused. How will you remember the ucture-types-and-functions/

Practice: Chromosomes4. Draw homologous chromosomes using the diagrams belowas guides. Label chromatids, sister chromatids, andsister chromatidscentromeres.a)b)centromerechromatid5. What is wrong with this picture?sister chromatidsIn a replicated chromosome, the two copies need to be identical sister chromatids. This picture usesdifferent colours for the copies, suggesting that they are homologous, which makes no sense. If they areconnected with a centromere, they must have the same DNA sequence same colour, same length, same genes.6. Sister chromatids and homologous chromosomes are oftenconfused. How will you remember the difference?Answers will vary.Homologous chromosomes are a pair of chromosomes (two centromeres). They are very similar but their DNA sequences are notidentical. They contain important differences that affect biodiversity (e.g. why your siblings look different).They make up a single replicated chromosome (one centromere). Sister chromatids have identical DNA sequences. During mitosis,sister chromatids split and form two identical chromosomes one for each of the identical daughter e-types-and-functions/

https://www.youtube.com/watch?v gcz1FOWw0Cg&ab channel AmoebaSisters

Growth and Development: Interphase The cell grows and thenumber of organellesincreases DNA in the nucleus iscopied

Cell Division: Phase 1 of Mitosis (Prophase) Nuclear membrane beginsto disappear DNA condenses intoduplicated chromosomes Each chromosome containstwo copies of the sameDNA (the copies were madein interphase)Note about diagram:Red chromosomes from mom; bluechromosomes from dadEach pair of chromosomes with the sameshape and length contains the same genelocations: they are a homologous pair ofchromosomes.

Cell Division: Phase 2 of Mitosis (Metaphase) Structures called spindlefibres guide chromosomemovement Chromosomes line up alongthe middle of the cell

Cell Division: Phase 3 of Mitosis (Anaphase) Copies of DNA are separatedand go to each end of the cell

Cell Division: Phase 4 of Mitosis (Telophase) Two nuclei form Each nucleus contains acomplete copy of the cell’sDNA

Cell Division: Cytokinesis Cytoplasm and organelles aredivided Two separate cells form The cells then begininterphase

Mitosis: SummaryFigure 1.9: Cell reproduction by mitosis results in daughter cells that aregenetically identical to each other and to the parent cell.http://cyberbridge.mcb.harvard.edu/mitosis 2.html

Discussion Questions1. What happens to the DNA ina cell during interphase? Whyis this step important for thereproduction process?2. In two or three sentences,describe what the cell cycleis.

Concept 3: Yeasts reproduce by budding.Yeasts are unicellular eukaryotic micro-organisms Commonly used to make dough, bread, pretzels, soysauce, cheese, vinegar Reproduce by asexual reproduction: buddingFigure 1.11: Yeast

Asexual Reproduction in Yeast: BuddingBudding: Yeast cell grows a budthat pinches off tobecome a separate cell New cell is smaller thanoriginal cell at first Eventually grows tothe same size asother yeast cellsFigure 1.11: Yeasts reproduceasexually by budding.

Discussion Questions1. In what ways is reproductionin yeasts and bacteria similar?In what ways is it different?2. Why is a daughter yeast cellidentical to the parent cell?

Concept 4: Moulds reproduce using spores.Moulds are composed ofmany eukaryotic cells Reproduce by asexualreproduction usingsporesFigure 1.12: Mouldsreproduce using spores.

Asexual Reproduction in Moulds: Spores Moulds form spores that aregenetically identical to themould cells they come from Spores are released intothe air from a structurecalled a sporangium When a spore lands in afavourable environment(warm, moist), it growsand divides by mitosisand cytokinesisFigure 1.12: Mouldsreproduce using spores.

Discussion Questions1. What role do spores play inthe asexual reproduction ofmoulds?

Concept 5: Plants have many ways to reproduceasexually.Plants reproduce sexually and asexually Asexual reproduction: Vegetative propagation New plants grow from a portion of the roots, stems, orleaves from an existing plant New plants are clones (copies) of the parent plantFigure 1.13: If you look closely at afield of strawberry plants, you willsee smaller plants growing near alarger plant. These smaller plantsare new plants that grow alongrunners. Runners are like stemsthat grow horizontally, above theground, from a full-grown plant.Eventually runners die, leavingindependent, identical plants.

Vegetative Propagation: ExamplePotatoes: New roots and shoots growfrom the eyes of a potato If you plant a potato withthis new growth, a potatoplant will develop The new plant will beidentical to the parent plantFigure 1.13

Artificial Vegetative PropagationArtificial vegetativepropagation uses techniques toproduce plants with specificcharacteristics Example: Grafting A bud, stem, or root iscut from one plant andjoined to another Used to produce treeswith high-quality fruit orresistance to disease

Discussion Questions1. Describe an example ofvegetative propagation.2. Why are new strawberryplants that form from runnersidentical to the parent plant?

Topic 1.2 Summary: What are different waysthat living things reproduce asexually? Bacteria reproduce bybinary fission. All eukaryotic cellsreproduce by the cell cycle. Yeasts reproduce bybudding. Moulds reproduce usingspores. Plants have many ways toreproduce asexually.

DNA condenses into duplicated chromosomes Each chromosome contains two copies of the same DNA (the copies were made in interphase) Note about diagram: Red chromosomes from mom; blue chromosomes from dad Each pair of chromosomes with the same shape and length contains the same gene locations: they are a homologous pair of chromosomes.

Related Documents:

provider (ISP) connections (including branch connections) No connections Minimal complexity (1–20 connections) Moderate complexity (21–100 connections) Significant complexity (101–200 connections) Substantial complexity ( 200 connections) Unsecured external connections, number of connections not users (e.g., file transfer protocol (FTP),

Trigonometry Unit 4 Unit 4 WB Unit 4 Unit 4 5 Free Particle Interactions: Weight and Friction Unit 5 Unit 5 ZA-Chapter 3 pp. 39-57 pp. 103-106 WB Unit 5 Unit 5 6 Constant Force Particle: Acceleration Unit 6 Unit 6 and ZA-Chapter 3 pp. 57-72 WB Unit 6 Parts C&B 6 Constant Force Particle: Acceleration Unit 6 Unit 6 and WB Unit 6 Unit 6

Figure 5: DVD, Blu-ray Player and Cable, Satellite, HDTV tuner Connections 10 Figure 6: DVD-A or SACD Player Connections 10 Figure 7: Video Recorder Connections 11 Figure 8: CD Player Connections 11 Figure 9: Audio Recorder Connections 12 Figure 10: AM/FM / Internet Radio Tuner Connections 12 Figure 11: USB Audio /iPod Connections 13

for three connections intended to be used for accelerated bridge construction. These connections include rebar hinge pocket connections, hybrid grouted duct connections, and SDCL steel girder connections. The document also presents a short background information and a concise summary of the main research study conducted toward

Moment resisting connections are used in multi-storey un-braced buildings and in single-storey portal frame buildings. Connections in multi-storey frames are most likely to be bolted, full depth end plate connections or extended end plate connections. The most commonly used moment resisting connections are bolted end plate beam-to-column .

Unit focused on building interpersonal communication skills, and Unit ð puts those skills to work by engaging students with their community. This unit involves creating and developing a community network and identifying employment opportunities available within one’s community. Vocational Connections Unit 4: Developing Community Connections Unit Overview: Topics Covered: Networking skills .

ice cream Unit 9: ice cream ka bio Unit 3: say it again kaa Unit 10: car kakra Unit 3: a little Kofi Unit 5: a name (boy born on Fri.) Koforidua Unit 4: Koforidua kↄ Unit 9: go Kↄ so Unit 7: Go ahead. kↄↄp Unit 9: cup kube Unit 10: coconut Kumase Unit 4: Kumasi Labadi Beach Unit 10: Labadi Beach

CAPE Management of Business Specimen Papers: Unit 1 Paper 01 60 Unit 1 Paper 02 68 Unit 1 Paper 03/2 74 Unit 2 Paper 01 78 Unit 2 Paper 02 86 Unit 2 Paper 03/2 90 CAPE Management of Business Mark Schemes: Unit 1 Paper 01 93 Unit 1 Paper 02 95 Unit 1 Paper 03/2 110 Unit 2 Paper 01 117 Unit 2 Paper 02 119 Unit 2 Paper 03/2 134