1. Cytology, Basic Genetics and Histology (COMPLETED) Flashcards

Question

Where do we find a phospholipid bilayer?

Answer 1

It is the plasma membrane around a cell.

Answer 2

Purple: The phosphate heads are the purple circles on the top and bottom. They are hydrophilic, loving water and this is great because they are in contact with water on the outside of the cell and also on the inside of the cell (cytosol) Green: jipids. The lipid tails are green and point inwards (away from the water) as they are hydrophobic and moving away from liquid.

Answer 3

Every cell in the body is in contact with liquid or water on the outside but also on the inside with cytosol. Basically there is alot of water around! a. Hydrophobic – water hating. Eg: fats The lipid bilayer is an example of hydrophobic where it does not like water. Think about oil in water. It does not dissolve but sits on globules b. Hydrophilic – Water loving. Eg: Phosphates love water

Answer 4

a. Hydrophobic The lipid bilayer is an example of hydrophobic where it does not like water. Think about oil in water. It does not dissolve but sits on globules b. Hydrophilic The phospholipid bilayer is an example of this.

Answer 5

1. **Transport of larger molecules** such as gluccose and proteins in and out of cells through** transmembrane proteins** (aka selective doorways) 2. **Immunological Identity** - signal to tell immune cells that it is safe and recognise our own cells. Think of it like red flags that say I am cell that belongs tho this body, please dont atack me 3. **Receptors for hormones** sit on its surface to receive 4. Cholesterol runs through the phospholipid bilayer. It supports the integrity of the membrane giving strength and reducing permeability.

Answer 6

Hydrogen (H+) Ions that contain fewer electrons than protons have a net positive charge and are called cations. Conversely, ions that contain more electrons than protons have a net negative charge and are called anions

Answer 7

Cholesterol is found in the cell membrane and is critical for the functioning of our cells. It gives our cells physical integrity. It is also essential for nerve function with regard to myeline on the end of nerves.

Answer 8

Cell junctions are contact and communication points between adjacent cell membranes of tightly packed cells. Tight junctions are cells that are tightly bound together and are found in the stomach, intestines and bladder. They provide a thick barrier.Transmembrane proteins fuse cells together to reinforce junctions and seal off passageways to prevent leaking and conditions such as leaky gut. Think like how we do woodwork Gap Junctions are small fluid filled tunnels between neighbouring cells. For example nerves and muscles

Answer 9

Stomach, Intestines, bladder

Answer 10

The nucleus is a spherical structure that contains the body’s genetic information in the form of DNA. Within the nucleolus is the nucleoli which contains RNA. The nucleus controls all of the cell’s functions and is therefore often called the brain of the cell. Each cell contains around 6 ft of DNA. Because it is so long it has to coil around itself and creates little strands called chromatin. In a resting state this is what it looks like = spaghetti! If that cell now wanted to reproduce the chromatin would arrange itself is very neat structures that look likes X's. These are chromosomes.

Answer 11

Situated in the nuclear membrane, nuclear pores are for substance movement in and out of the nucleus

Answer 12

The cytoskeleton is made up of a network of protein filaments (microtubules and microfilaments), that extend and through the cytosol spreading out through the cell. It is the scaffolding of the cell. These protein filaments assist with 1. Movement Microtubules are major components of the cytoskeleton. Organelles use them like a tunnel to move to a different part of the cell. Eg: Enable white blood cells to move to a site of injury; enable muscle contraction in muscle cells 2. Structure and shape They are very strong and rigid and provide physical support and shape to the cell 3. Cell Division They help move chromosomes apart to split them up during mitosis.

Answer 13

Bean shaped structures withing the cell. The power house of the cell. It generates ATP through either aerobic or anaerobic respiration. ATP = Adenosine triphosphate

Answer 14

Muscles cells needed for the energy to produce contraction. Particularly the heart which is 95% muscle. In these muscles there can be several thousand mitochondria.

Answer 15

Aerobic which produces 38 ATP but loses 2 in the process so a net gain of 36.

Answer 16

Glucose* + Oxygen = Carbon dioxide + Water + Adenosine Triphosphate (ATP) *Can use fats and proteins, in the order, but not as effective as sugar so last resort

Answer 17

They are the smallest spherical structure you will find within the cell yet they represent 25% of the mass of the cell. The job of ribosomes in the synthesise (produce) proteins. They receive instructions from MRNA. They are free in the cytosol or connected to the rough endoplasmic reticulum

Answer 18

Ribosomes that are stationary and connected to the endoplasmic reticulum produce proteins that are transported out of the cell to be used elsewhere. Hormones are an example of this as they are transported to where they are needed. Ribosomes that are free in the cytoplasm of the cells produce proteins that remain in the cell.

Answer 19

Usually it is close to the nucleus. It is a network of flattened membranes forming tubes. Rough and smooth

Answer 20

It has ribosomes stuck to the outside of it which is what gives it its rough appearance. Ribosomes on the outside synthesises proteins and these will make their way into the ER where they are packaged and then transported out.

Answer 21

It has several roles depending on where it is in the body. It contains unique enzymes to perform these roles. Main role is to synthesise **lipids** are **lipid bassed steroid hormones** such as oestrogen and progesterone are produced. Other roles: * In the liver the smooth ER is used detoxify alcohol and drugs * In muscle where it is called the sarcoplasmic reticulum) it binds to calcium to make it available to the muscle to use for contraction.

Answer 22

The Golgi apparatus is described as the post office or packaging plant of the cell. It receives proteins from the rough endoplasmic reticulum. Enzymes modify, sort and package proteins into vesicles to facilitate their transport within or out of the cell.

Answer 23

Lysosomes are larger vesicles which contain up to 60 enzymes that perform a key role in cell digestion. They are likened to the recycling centre of the cell. They recycle worn out organelles and waste products by engulfing and digesting them and returning the output of this to the cytosol to be reused or excreted. This is what they do to mitochondria. They have an immune function digesting foreign cells. Think PacMan. They are phagocytes.

Answer 24

Chromosomes are found in the nucleus of most living cells, carrying genetic information in the form of genes. They are thread like structures of nucleic acids and protein. They are formed of DNA that is coiled up **Each cell in the body** (except gamete cells) have 23 pairs of chromosomes

Answer 25

Males. In males the two sex hormones are different The 23rd chromosome controls the inheritance of sex. In men, if there is a genetic disease on an X chromosome, the Y cannot counteract possibly leading to sex-linked genetic diseases in males.

Answer 26

Genes are the hereditary units of the body. They are subsections of DNA that provide the instructions to make proteins. They are located along chromosomes and there are thousands on each chromosome. They hold the information to build and maintain cells and pass genetic traits to offspring. Every single somatic cell contains the full genome but only certain genes are working (switched on) depending on their jobs. One gene codes for the production of one protein.

Answer 27

a. Transcription RNA takes a copy of the DNA and passes it to Ribosomes in the form of MRNA b. Translation Ribosomes use the instructions to produce a chain of amino acids to form the required protein

Answer 28

DNA is housed within the nucleus and holds the genetic instructions for producing proteins. Think of it like a recipe book where each page has a recipe for a different protein. However we need to get these instructions to the ribosomes that are outside of the nucleus. This occurs in two phases: Transcription and Translation Transcription: Photocopy * DNA in the nucleus will unravel a little to expose a gene (which is the instruction for a given protein - a page of the recipe book). * A copy of the protein instructions is given to the (messenger RNA) MRNA which passes out of the nucleus and into the cytoplasm * It finds a ribosome and passes on the instructions Translation: Convert instructions to a protein * Ribosome reads the code and translates the instructions and pull together the amino acids into a chain that makes a new protein

Answer 29

A change in the genetic information. DNA consists of various sequences of four amino acids (A, T, C, G). A mutation changes this sequence. 200 eggs instead of 6 in the recipe

Answer 30

Somatic cells are all the cells in the body except for sex cells. They have a diploid nucleus meaning that have 23 pairs of chromosomes. They divide through mitosis to produce two identical daughter cells. Gametes are sex cells. They have a haploid nucleus. They have 23 chromosomes rather than 23 pairs. They divide by meoisis

Answer 31

A zygote is formed from the fusion of a male (sperm) gamete and a female (ovum) gamete. Each gamete has 23 chromosomes. The zygote has 23 pairs of chromosomes - one pair from each parent.

Answer 32

The zygote is a diploid cells, meaning it has 2 pairs of 23 chromosomes. It will undergo mitosis and develop into an embryo and then a foetus

Answer 33

Genetic information is replicated exactly. The two lots of identical DNA line up in the middle of the cell and the cell will break into two. 46 chromosones go into one cell and 46 chromosomes into the other cell. Number of divisions? 1 Number of daughter cells? 2 Number of chromosomes in daughter cells? 23 pairs so 46 Diploid or haploid? Diploid (46 chromosomes) Daughter cells identical or different? Identical End result? 2 new identical diploid body cells Purpose? Body repair and growth

Answer 34

Genetic information is replicated but **not** exactly. Parent Cell chromosomes are copied but some of the chromosomes are mixed up a little. The non identical DNA line up in the middle of the cell and the cell will break into two. 46 chromosones go into one cell and 46 chromosomes into the other cell. A second division now happens where 23 chomosomes are pulled one way and 23 the other way to form another division producing 4 unique cells. The process we use to produce gametes. (sex cells) Number of divisions? 2 Number of daughter cells? 4 Number of chromosomes in daughter cells? 23 Diploid or haploid? Haploid Daughter cells identical or different? Different End result? 4 unique haploid reproductive cells Purpose? Reproduction - making eggs and sperm (gametes)

Answer 35

No mutations on somatic cells cannot be inherited. Mutations in gamete cells can be inherited.

Answer 36

* Active requires energy and passive does not * Active moves from low to high concentration and passive from high to low concentration

Answer 37

a. Osmosis – the passive movement of water to even out concentration b. Diffusion - the movement of small substances from a high to a low concentration. Usually gases such as oxygen and CO2 c. Facilitated diffusion – uses transmembrane proteins to move larger substances from high to low concentration. Glucose molecules and positively charged ions for example

Answer 38

a. Pumps – Movement of molecules up the concentration gradient using a protein pump. Eg: The Sodium/potassium pump to allow the nerve cells to transmit a nerve impulse The proton pump that pushes acid into the stomach b. Endocytosis – Endo = inside A form of active transport where a cell takes in materials from the outside by engulfing and fusing them with its plasma membrane. c. Exocytosis – Exo – outside A form of active transport where a cell excretes material from the inside to the outside by fusing the material with the cell membrane before being expelled.

Answer 39

Passive Transport and specifically it is facilitated diffusion. Glucose molecules are too large to cross through the cell membrane by diffusion alone. They use transmembrane proteins to go through the membrane.

Answer 40

Moves the sodium and potassium ions against the concentration gradient pushing sodium out of the nerve cell to make it negatively charged and able to transmit a nerve impulse

Answer 41

a. Endocytosis – A form of active transport where a cell takes in materials from the outside by engulfing and fusing them with its plasma membrane. b. Phagocytosis – Cell eating – of solids c. Pinocytosis – Cell drinking - of liquids d. Exocytosis – A form of active transport where a cell excretes material from the inside to the outside by fusing the material with the cell membrane before being expelled.

Answer 42

Epithelial Tissue Connective Tissue Muscular Tissue Nerve Tissue

Answer 43

Epithelial tissue consists of* tightly* packed cells arranged in *continuous* sheets in either single or multiple layers. Divided into *covering (lining*) and *glandular*, epithelial tissue provides a* selective* barrier for protection and *secretio*n of substances

Answer 44

* GIT * blood vessels * heart * lungs * reproductive organs * urinary tract * skin * eyes

Answer 45

A gland is a single cell or groups of epithelial cells that produce secretions. There are two types: Exocrine glands secrete into ducts. Eg: saliva, milk, sweat, sebum, enzymes Endocrine glands secrete into the blood. They always produce and secrete hormones. The hormones enter the interstitial fluid and the diffuse into the blood.

Answer 46

* Bones * cartilage * ligaments * blood

Answer 47

a. Extracellular matrix which is made up of ground substance and protein filaments. Protein filaments are made up of elastin and collagen. b. Cells, specifically Adipocytes, Leukocytes and Fibroblasts that are widely spaced apart

Answer 48

Connective tissue is one of 4 types of tissue in the body. It is the most abundant in the body. It is a strengthening tissue. We find it in bones, ligaments, tendons, blood. Although we find it in many different places in the body, it always has two main components - cells and extracellular matrix. Cells are widely spaced and it is the space in between them that is called the extracellular matrix. a. Extracellular matrix is made up of - Ground Substances which determine whether the connective tissue is going to be a fluid like blood or hard and calcified like we see in bone. - The protein fibres Collagen (for strength) and Elastin (for flexibility). The percentage of these two fibres will vary depending on the function of the connective tissue in question. For example bone is very strong and hard and will have a higher percentage of collagen compared to elastic fibres. On the other hand if we think about blood vessels, they would need to have a bit of give for the different pressures due to dilation and constriction and therefore the have a higher percentage of elastin compared to collagen. Skin is another example where we might find more elastic fibres as the skin can be pinched and stretched and goes back to normal. b. has three types of specialist cells: 1. Adipocytes which are fat cells 2. Leukocytes for immunity - macrophages, lymphocytes and mast cells 3. Fibroblasts to produce the collagen and elastin fibres in the extracellular matrix

Answer 49

Collagen Fibres: For strength Made from protein collagen Found especially in bone, ligaments, tendons Made from strong fibres; occur on parallel bundles for extra strength Elastic fibres For stretch Made from protein in elastin surrounded by glycoprotein to add strength Found in skin, blood vessels walls and lung tissue Structure: strong but with stretch and a lot of tissue to return to original shape. Smaller diameter

Answer 50

Adipocytes: Store triglycerides ie: fat storage cells White blood cells - Lymphocytes: Synthesise and secrete antibodies for defence White blood cells - Macrophages: Phagocytose debris and pathogens Fibroblasts Most numerous type of connective tissue. Secrete protein fibres to make collagen, elastin and matrix. Active in repair and healing

Answer 51

1. Provide a structural framework - bone and cartilage does this 2. Transport nutrients and waste - blood does this 3. Provides protection for vital organs – bone, cartilage and adipose (fat) do this 4. Provides support and interconnection - tendons and ligaments do this 5. Provide insulation - adipose tissue does this 6. Acts as an energy store 7. Production of blood and lymphatic cells - adipose tissue and bone marrow do this 8. Involved in defence and repair – Blood and lymph do this

Answer 52

Membranes in the body combine epithelial and connective tissue. They are flat sheets that cover or line areas of the body a. Cutaneous – skin. Epidermis is made of epithelial cells and the dermis is made of connective tissue b. Mucous – line hollow organs that open to a surface of the body c. Serous – line body cavities that do not open to the exterior d. Synovial - A lubricating fluid in in many joints

Answer 53

Each membrane has its own function. In common they all combine epithelial and connective tissue that cover or line areas of the body. Synovial membranes are the only membranes that line the cavities between the movable joints in the body. They also surround tendons that could be injured by rubbing against bones

Answer 54

The mucous membrane lines digestive tract, respiratory tract and **genito-urinary tracts**. It secretes **enzymes** necessary for **digestion** and is the site for absorption. The epithelial layer contains **goblet** cells that produce and secrete **mucus** which protects the lining membrane from mechanical and **chemical** injury/drying. It also **traps** foreign particles in the **respiratory** tract.

Answer 55

No. Its lines body cavities the DO NOT open to the exterior. eg: Heart, Lungs, Abdomen

Answer 56

The serous membrane lines the pleura (lungs) pericardium (heart) peritoneum (abdomen)

Answer 57

Inner Visceral layer – surrounds organs Outer Parietal layer lines a cavity In between we have serous fluid

Answer 58

It enables an organ to glide freely within the cavity without friction

Answer 59

Synovial membranes line **cavities** of freely moveable joints. It consists of **synviocytes** that secrete **synovial fluid** which nourishes the moveable joint cavities which it lines. It also surrounds **tendons** that could be injured by **rubbing** against bones.

Answer 60

Meiosis is involved in the formation of gametes (sex cells). It produces 4 haploid cells through 2 divisions. The daughter cells produced are non-identical as the chromosomes overlap (hence genetic variability). A haploid nucleus means they contain 23 chromosomes.

Answer 61

Cells are tightly packed to prevent leakage. They are in well organised layers/sheets. It is a lining tissue not a strengthening tissue. In connective tissues cells are more widely spaced out with the spaces filled in with ground substances and protein fibres.

Answer 62

Chromosomes are formed of DNA that is coiled up

Answer 63

Centrioles are important for cell division. Each cell has two centrioles. Before division one moves to the other side of the cell. Just before division they release protein spindles which attach to the chromosomes and pull the chromosomes apart - 46 one way and 46 the other.

Answer 64

Meiosis is involved in the formation of gametes (sex cells). It produces 4 haploid cells through 2 divisions. The daughter cells produced are non-identical as the chromosomes overlap (hence genetic variability). A haploid nucleus means they contain 23 chromosomes.

Answer 65

DNA forms a double helix which coils around proteins called histones.

Answer 66

23 pairs of chromosomes in every somatic cell nucleus Chromosomes are formed of 2 metres of DNA that has coiled up Genes are subsections of DNA located along chromosomes that act as instructions to make proteins.

Answer 67

It is a very important structure also knows as the phospholi[id bilayer. It's jopb is to - maintain the shape of the cell - acts as a selective barrier meaning it lets things in and out but only what is wanted.

Answer 68

It is a very important structure also knows as the phospholi[id bilayer. It's jopb is to - maintain the shape of the cell - It is a semi permeable, selective and flexible barrier that separates the cells internal and external environment.

Answer 69

Where do we find it? What is it made up of? How is it arranged? What are some examples in the body? What is its role?

Answer 70

A collection of cells that work together to perform the same function

Answer 71

An organ which produces and releases substances that perform a specific function in the body Endocrine - secrete substance in to the blood stream Exocrine - secrete substance from a duct onto a surface

Answer 72

Where do we find it? Covering/lining tissue What is it made up of? Very closely packed cells How is it arranged? * Simple epithelium - a single row/layer of cells which is useful for easy absorption and excretion but at the same time means they are more vulnerable to damage so they don't tend to be in places where there is a lot of mechanical stress * Stratified epithelium has layers and is found in places with more mechanical stress but still not in very stressed areas. What are some examples in the body? Lining blood vessels, heart, lungs, urinary tract, GIT, skin, reproductive organs What is its role? * Selective barrier, secretions of substances. * Can form glands secreting hormones, mucus

Answer 73

A collection of cells that work together to perform the same function

Answer 74

An organ which produces and releases substances that perform a specific function in the body Endocrine - secrete substance in to the blood stream Exocrine - secrete substance from a duct onto a surface

Answer 75

Where do we find it? The most **diverse** and **abundant** tissue in the body What is it made up of? Although diverse each connective tissue cell will have certain things in common 1. Extra Cellular Matrix made up of ground substances (that determone the function of the connective tiisue) 2. Cells - all connective tissues has these cells no matter what the function of the tissue is: * Fibroblast cells - makes collagen and elastic fibres * Adipocyte cells * White blood cells, particulaly macrophages, lymphocytes and mast cells How is it arranged? Scattered arrangement in the extracellular matrix What are some examples in the body? Bones, cartilage, blood , tendons,ligaments, adipose tissue What is its role? * Supportive and helps to attach structures (tissues and organs) on to other structures, anchoring them * Helps in muscle and bone formation * Helps the working of the blood and lymph

Answer 76

Ligaments and tendons are both made up of fibrous connective tissue, but that’s about where the similarity ends. Ligaments appear as crisscross bands that attach bone to bone and help stabilize joints. Tendons, located at each end of a muscle, attach muscle to bone.