SNC2D 生物知识整理（更新至2018-10-09）

By Pegasis

Cell Theory^细胞理论

1. All living things are made up of at least one cell.
2. We need at least one cell to live.
3. All cells come from other cells.

Types of Cells^细胞种类

Comparison Prokaryote&Eukaryote

Prokaryote^原核生物

A cell that does not contain a nucleus or other membrane-bound organelles.

Eukaryote^真核生物

A cell that contains a nucleus and other organelles, each surrounded by a thin membrane.

Comparison Animal Cell&Plant Cell

• Plant cell have a cell wall
• Plant cell have chloroplasts
• Plant cell have large vacuoles

Animal Cell

Cell Membrane^细胞膜

• Made of two layers
• Supports the cell
• Controls what comes into and out of a cell
• It's “Semi-permeable membrane”: only lets some substances pass

Nucleus^细胞核

• Controls the cell
• It holds the chromosomes^染色体 that have the information to control all the activities

Nucleolus^核仁

• Makes ribosomes, maybe more than one in a cell, found in the nucleus

Chromosomes^染色体

• Determines what traits a living thing will have, passes information from parent to offspring.
• Depending on the stage of the Cell Cycle, chromosomes will have different appearances, and have different names.

Cytoplasm^细胞质

• Jelly-like material that fills the cell (mostly water and other chemicals)
• All organelles are held in the cytoplasm

Mitochondrion^线粒体

• The "power plants" of the cell
• Cells contain many mitochondria
• They change food into energy (cellular respiration)
• The more active the cell is (muscle cells), the more mitochondria it has (compared to fat cells)

Endoplasmic Reticulum (ER)^内质网

• A folded membrane that moves materials (such as proteins) throughout the cell
• It extends from the nuclear membrane throughout the cytoplasm to the cell membrane

Golgi Bodies^高尔基体

• Collect and processes material to be removed from the cell
• They also make and secrete mucus^粘液
• The more mucus the cell secretes (intestine^肠道 cells), the More Golgi bodies it has

Vacuoles^液泡

• A very small bubble filled with liquid
• Surrounded by a single membrane
• Functions include: Storing food and water, removing waste, and maintaining pressure inside the cell

Ribosome^核糖体

• Organelles that build “proteins” that are important for cell growth and reproduction
• Often connected to the endoplasmic reticulum
• A cell may have as many as 500,000

Centrioles^中心粒

• Only in animal cells
• Used in cell reproduction to help the chromosomes arrange before cell division

Lysosomes^溶酶体

• Digests food particles with enzymes
• Pinched of pieces of Golgi apparatus

Microtubules^微管

• rod-like, hollow protein tubes that act like tracts along with organelles, like vesicles and mitochondria
• can move
• part of the cytoskeleton

Plant Cell

Cell Wall^细胞壁

• Made of a rigid/strong and porous (has holes) material called cellulose^细胞膜质
• It provides support for the plant cells and protection from physical injury
• Only plant cells have cell wall
• Immediately inside the cell wall is the cell membrane

Vacuole^液泡

• Plants usually have one large vacuole
• Vacuole functions are the same as in an animal cell

chloroplasts^叶绿体

• Only in plant cells
• Contain chlorophyll that helps plants get energy from the sun and change that into food
• Gives leaves their green color

Cell Division^细胞分裂

Why

• Cell division maintains a surface area to volume ratio of the cell that enables effective exchange across the plasma membrane. Volume of a cell increases faster than the surface area of the plasma membrane
• Maintains a manageable volume to maintain nuclear control (control of all cell activities)

Functions

• Healing & Tissue Repair
• Growth & Development
• Reproduction

Prokaryotes

• Have no nucleus
• Have a single circular chromosome
• Simply divide their cells in two by binary fission

Eukaryotes

Cell Cycle^{细胞生命周期}

Mitosis^有丝分裂

• Mitotic division results in genetically identical eukaryotic cells (a clone)
• Mitosis is the basis of asexual reproduction

Interphase

• Cell grows & prepares itself for mitosis by building proteins
• Duplicates genetic material called chromatin^染色质, now double stranded
• Centrioles^中心粒 are also replicated, more organelles form

Prophase

• The chromatin^染色质 condenses into discrete chromosomes^染色体
• Chromosomes shorten & thicken, now visible in light microscope
• Nuclear membrane & nucleolus breakdown, freeing the chromosomes
• centrioles move away from each other & form spindle fibers

Metaphase

• Nuclear membrane has disappeared
• Centrioles have reached opposite poles
• Chromosomes line up in the middle of the cell or equator^赤道板
• Chromosomes are attached to the spindle fibers by their centromeres^着丝粒

Anaphase

• Spindle fibers^纺锤纤维 shorten to pull and separate duplicated chromosomes to opposite poles of the daughter cells
• Chromosomes are now referred to as daughter chromosomes
• Daughter chromosomes move to opposite ends of the cell

Telophase

• Daughter chromosomes have reached opposite poles & begin to uncoil
• Nuclear membrane & nucleolus reform
• Spindle fibers disappear
• Daughter cells are genetically
• Cytokinesis^胞质分裂 begin

Meiosis^减数分裂

• Meiosis results in a halving of the chromosome number in preparation for fertilization
• Meiosis shuffles genes in new combinations
• Meiosis results in genetically different cells
• Meiosis and fertilization are the basis of sexual reproduction

Cancer^癌症

Difference from Cancer Cells to Normal Cells

• Spend less time in interphase
• Have uncontrolled mitosis
• Grow faster than normal cells
• Can break away from groups of cells and travel to other places in the body
• Most of them have parts that allow them to grip and grab onto other cells and tissues

Types of Tumor

Benign tumor^良性肿瘤

• Does not interfere the functioning of surrounding cells

Malignant tumor^恶性肿瘤

• Interferes with the functioning of surrounding cells

Types of Cancer

Carcinomas^细胞癌

• Develop in the linings of the body (e.g. Skin, stomach lining, lungs, breast, liver and pancreas)
• Most common forms of cancer

Lymphomas^淋巴癌

• Develop in the lymph nodes, bone marrow, or spleen
• Can easily spread to other parts of the body through the lymph and bloodstream

Sarcomas^肉瘤

• develop in the bones or connective tissues
• can spread through the bloodstream

Causes of Cancer

Genetic^遗传

caused by inherited gene

Carcinogens^致癌物

caused by agents in the environment

Mutations^突变

caused by random change in the genetic code

Radiation^放射线

caused by high ionizing radiation

Stages of Cancer

Stage 0

• Carcinoma in situ^原位癌

Stage 1-3

• Larger tumor size
• May spread to nearby organs

Stage 4

• Has spread to distant tissues or organs (Metastasis^转移)

Cancer Screening^癌症检查

Biopsy^{活组织检查}

• Doctors need to know the tumor is cancerous or not, Benign or not
• In biopsy, doctors removes a sample of the cells from the tumor to analyze

Pap test^{宫颈癌涂片检查}

• Take a sample of cervical cells
• Determine by see if cells are growing abnormally

PSA test^{前列腺特异性抗原测试}

• Take a sample of blood
• Determine by the existence of prostate specific antigen
• Prescribed for men >50 years

Mammography^{乳房X线照相术}

• A type of x-ray
• Used to screen for signs of breast cancer

Colonoscopy^{结肠内窥镜}

• Endoscopic examination of the large intestine
• Use an endoscope or colonoscope

Reducing Risk

• Change in diet
• Avoid smoking tobacco
• Exercise

Cancer Treatment

Each cancer is different, so treatments may vary from person to person

Surgery^手术

• Physically removing the cancerous tissue
• Use if tumor is easily accessible

Chemotherapy^化疗

• Using drugs to treat the cancer
• Works by slowing or stopping cell division
• Often used to shrink the tumor before surgery or radiation
• Side effects may include nausea, hair loss or fatigue^疲劳

Radiation^放疗

• Use Ionizing radiation
• By damaging the DNA of cancer cells so they can't divide

Stem Cells^干细胞

Stem cells are undifferentiated cell that can become a specialized cell

Types of Stem Cells

Totipotent Cells^全能细胞

• From the fusion of egg^卵子 and sperm^精子 (fertilized egg^受精卵)
• Can be used to produce an entire organism
• May be called master cells

Pluripotent Cells^多能细胞

• Derived from totipotent cells
• Are the true stem cells usually obtained from embryonic stem lines (?????)

Embryonic Stem Cells^{胚胎干细胞}

• Can differentiate into any kind of cell

Advantages & Disadvantages

Tissue Stem Cells^{组织干细胞}

• From skin and bone marrow
• Can differentiate into specialized cells

Adult Stem Cells^{成体干细胞}

• May be obtained from tissues such as umbilical cord blood
• Have been used for years to treat leukemia^白血病

Advantages & Disadvantages

Tissues^组织

Cell Organization

Tissue

• A collection of similar cells
• Performs a particular, but limited function

Organ

• a structure composed of different tissues working together
• Performs a complex body function

Organ System

• a system of one or more organs and structures that work together
• Perform a major vital body function (such as digestion or reproduction)

Animal Tissues

Epithelial Tissue^上皮组织

• a thin sheet of tightly packed cells
• covers body surface, internal organs and body cavities
• Lines^内衬 internal organs and body cavities

Connective Tissue^结缔组织

• Provides support and protection for various parts of the body
• Includes tendons, ligaments, bones, cartilage, blood, and fat

Muscle Tissue^肌肉组织

• A group of specialized tissues
• Containing proteins that can contract and enable the body to move

Skeletal Muscles^骨骼肌

Help you to move

Smooth Muscles^平滑肌

Help your organs to move

Cardiac Muscles^心肌

Help your heart to move

Nerve Tissue^神经组织

• Conducts electrical signals from one part of the body to another

Plant Tissues

Vascular Tissue^导管组织

• Transports water and nutrients

Xylem^木质部

Moves water and minerals up from the roots

Phloem^韧皮部

Moves the photosynthesized sugar around

Epidermal Tissue^表皮组织 (=Dermal Tissue)

• Forms the protective outer covering
• allows the exchange of materials in and out of the plant

Ground Tissue^基本组织

• Provides support
• Stores water and nutrients
• Photosynthesis happens in it

Meristematic Tissue^分生组织

• Is where growth occurs
• The cells in meristematic tissue are stem cells

Digestive System^消化系统

Propose

1. Takes in food (ingestion)
2. Digests food (digestion)
3. Removes the remaining waste (egestion)

Part 1: Digestive Tract^消化道 (=Alimentary Canal)

Lined Materials^内衬材料

Epithelial Cells^上皮细胞

• Secrete mucus (thick liquid) from goblet cells
• Mucus protects from digestive enzymes and acid
• Lubricates or makes the tract easy to move through

Muscle Tissue^肌肉组织

Nerves Tissue^神经组织

Mouth

• Used to mechanically break down food by chewing with saliva^唾液
• Saliva contains enzymes that break down the starches

Esophagus^食管

• A muscular tube connecting mouth to stomach
• The movement of food is controlled by nerves and muscles

Peristalsis^蠕动

The process of moving food through the esophagus into the stomach with the help of muscles

Stomach^胃

• Holds food
• Churns food
• Lined with cells that produce digestive enzymes and acids
• Muscles contract to mix food
• Many nerves

Small Intestine^小肠

• 6m long
• Most digestion occurs here
• Small, fine blood vessels
• Smooth muscle
• Nutrients diffuse through wall to blood vessels
• Occurs through the villi
• Absorption occurs through the villi and microvilli

Large Intestine^大肠

• 1.5m long
• Larger diameter
• Primarily for water absorption
• Waste material passed on to rectum

Rectum^直肠

• Storage of feces and water adsorption
• Waste excreted through anus

Part 2: Accessory organs^辅助器官

Liver^肝脏

• Produces bile for the small intestine
• Bile helps to break down fats

Pancreas^胰脏

• Produces insulin to regulate amount of glucose in blood

Gall Bladder^胆囊

• Stores bile between meals
• Bile is released in to the small intestine through in bile duct

Circulatory System^循环系统

Propose

1. Carry nutrients to cell from intestine
2. Carry CO₂ and waste away from cell to the lungs and kidneys respectively
3. Get O₂ from the lungs for the body
4. Carry chemical messages between parts of the body
5. Move white blood cells that fight viruses or bacteria
6. Regulate body temperature

Heart

Cardiac Muscle Tissue

• Muscle tissue only found in heart
• All tissue contracts at the same time
• Results in the pumping of blood

Nerve Tissue

• Controls how often the heart beats

Connective Tissue

• Protects the heart

Blood

• Connective tissue that circulates through the body

Red Blood Cells (=erythrocytes)

• Make up almost 50% of all blood by volume

• Contains several hundred thousand hemoglobin (a kind of protein)

  • Hemoglobin Transports O₂ throughout the body
  • Hemoglobin gives blood its bright red color

• Produced in bone marrow

• No nucleus

White Blood Cells (=leukocytes)

• Make up less than 1% of blood volume
• Fight infection, destroy invading bacteria and viruses
• Have nucleus

Platelets^血小板

• Make up less than 1% of blood volume
• Small cells that help in blood clotting

Plasma^血浆

• Makes up 50% of the blood by volume
• Protein-rich fluid that carries blood cells

Blood vessels

Arteries^动脉

• Carry blood away from the heart

• Thicker walls to withstand pressure

  • Pressure is due to heart pumping blood into them

Veins^静脉

• Carry blood to heart
• Low pressure
• Thinner walls than arteries
• Have valves to prevent the blood from flowing backwards

Capillaries^毛细血管

• Connect arteries to veins

• Thin walls

  • Allow O₂ and nutrients to diffuse to body tissue
  • Allow CO₂ and other wastes diffuse from tissue into blood

Summary

Diseases

Coronary Artery Disease

• Plaque^斑块: fat, cholesterol and calcium deposits in the vessels that supply the heart with blood
• Leads to a heart attack
• Can be passed down from family or caused by bad lifestyle choices
• Symptoms: tired, dizzy, pain in chest/arms
• Diagnosed^诊断 with angiogram^血管造影

Heart Attack

• Coronary arteries^冠状动脉 completely blocked
• Heart receives no O₂ – stops pumping and starts to die
• Symptoms: Chest pain, Shortness of breath, Nausea, Anxiety, .....

Respiratory System^呼吸系统

Propose

• Provide O₂
• Remove CO₂
• Work together with the circulatory system

Parts

Mouth

Nose

• Dirt in the air and other particles are trapped by tiny hairs and sticky fluid

Pharynx^咽

Trachea^气管

• Held open by rings of cartilage^软骨

  • Cartilage is a special type of connective tissue that is strong and flexible (can bend)

• Epithelial cells inside the trachea produce mucus^粘液

• Many epithelial cells have cilia^绒毛

  • Help move mucus and remove any left over bad material

Bronchi^支气管

• Two in all
• Separates from trachea

Bronchioles^细支气管

• Separates from bronchi
• Allows the air to move to all parts of the lungs

Lungs^肺

Alveoli^肺泡

• Occurs gas exchange
• Surrounded by capillaries
• The wall of it is one cell thick

Diaphragm^隔膜

Ribs^肋骨

Gas Exchange

• Main purpose of the respiratory system
• Happens in alveoli^肺泡
• The amount of O₂ in the capillary blood is always less than the amount of O₂ from the air. So, the O₂ always diffuses into the blood
• The amount of CO₂ in the capillary blood is always more than the amount of CO₂ from the air. So, the CO₂ always diffuses into the air

Other Systems

• Excretory^排泄系统
• Muscular^肌肉系统
• Skeletal^骨骼系统
• Nervous^神经系统
• Immune^免疫系统
• Endocrine^{内分泌系统}
• Reproductive^生殖系统
• Integumentary^外皮系统