Cells Make up the Human Body [2]

Question 1

Name the 6 main structures in a cell

Answer 1

Cell membrane
Cytoplasm
Organelles
Cytosol
Cytoskeleton
Inclusions

Question 2

Cytoplasm

Answer 2

Parts of the cell within the membrane, except for the nucleus.

Question 3

Cytoskeleton

Answer 3

Scaffolding of protein fibres, provides cell structure.

Question 4

Organelles

Answer 4

Structures suspended in the cytoplasm that carry out specific functions.

Question 5

Cytosol

Answer 5

Liquid part of cytoplasm, 75-90% water

Question 6

State the structure, location and function of the nucleus.

Answer 6

Spherical organelle protected by a double nuclear membrane.

Stores DNA, which contains inherited information and controls the cell’s function.

Question 7

State the structure, location and function of the ribosome.

Answer 7

Very small spherical organelles that join amino acids to form proteins. Found free in the cytoplasm or at the endoplasmic reticulum.

Question 8

State the structure, location and function of the endoplasmic reticulum.

Answer 8

Pairs of parallel, labyritnth-like membranes surrounding the nucleus. Transports molecules and provides a surface for chemical reactions.

Question 9

State the structure, location and function of the golgi body.

Answer 9

Stacked membranes near the nucleus that package proteins (produced by ribosomes and transported via ER) into vesicles for excretion.

Question 10

State the structure, location and function of lysosomes.

Answer 10

Small membrane-bound spheres formed by the golgi body containing digestive enzymes. Break down large molecules or material inside incoming vesicles.

Question 11

State the structure, location and function of the mitochondria.

Answer 11

Sausage-like organelles spread throughout the cytoplasm with a double membrane. Inner membrane provides surface area for cellular respiration to occur.

Question 12

State the structure, location and function of cillia and flagella.

Answer 12

Projections from the cell that assist in movement of the cell or its inner contents. Cilia: hairy, flagella: tail.

Question 13

Describe the structure of the cytoskeleton and its function.

Answer 13

Framework of microtubules and microfilaments that gives cell structure and assists in movement.

Microtubules: hollow rods controlling organelle movement

Microfilaments: move organelles or entire cell

Question 14

Inclusions and examples

Answer 14

Chemicals in cytoplasm, e.g. haemoglobin, pigments in eyes/hair, melanin.

Question 15

What is the centriole

Answer 15

Organelle in animal cells that form spindle fibres during cell replication

Question 16

What is the difference between rough and smooth endoplasmic reticulum

Answer 16

Rough ER: lined with ribosomes, transports proteins

Smooth ER: manufactures lipids

Question 17

What is extracellular fluid and its function

Answer 17

The immediate environment outside of cell membrane, transports materials travelling to or from cells.

Question 18

What is homeostasis

Answer 18

Where body systems cooperate to maintain a constant cellular environment (fluid must have constant temperature and concentration)

Question 19

Describe the structure of the cell membrane

Answer 19

Fluid mosaic model - many kinds of molecules constantly changing position

Phospholipid bilayer - each phospholipid has a hydrophillic phosphate head and a hydrophobic lipid tail

Semi-permeable - allow certain molecules through more easily than others

Proteins (receptor, carrier, channel, cell identity marker, cholesterol)

Question 20

What are the functions of the cell membrane

Answer 20

• physical barrier between cytoplasm and fluid as their compositions are different
• regulates passage of materials (intake of ions and nutrients, removal of waste)
• senses changes in extracellular fluid
• supports cell

Question 21

What is simple diffusion

Answer 21

The spreading out of liquid and gas molecules along the concentration gradient (from areas of high to low concentration).

Question 22

What is osmosis, and what is the most important solvent in the human body

Answer 22

The diffusion of a solvent through a semi-permeable membrane along the concentration gradient (passive process). Water is the most important solvent.

Question 23

What are the three types of cells influenced by osmosis?

Answer 23

Hypotonic - higher concentration of water inside of cell than out (bulging/swelling)

Isotonic - equal concentration of water on both sides (normal)

Hypertonic - lower concentration of water outside of cell than inside (dehydrated and shrivelled)

Question 24

What is facilitated transport, and what are the two types of proteins?

Answer 24

Where proteins in the cell membrane allow molecules to pass through.

• Channel proteins: allow dissolved molecules to pass through, avoiding hydrophobic inner portion.
• Carrier proteins: changes shape so that it opens on one side at a time.

Question 25

What are the characteristics of carrier mediated transport

Answer 25

Molecule - specific Carriers can become saturated (will not go faster if concentration increases) Hormones regulates carrier mediated transport

Question 26

What is carrier mediated transport, and what are the two types

Answer 26

Proteins that open on one side at a time allow molecules through. Facilitated diffusion and active transport

Question 27

What is active transport What is an example of active transport

Answer 27

An active process that moves substances against the concentration gradient through carrier proteins Example: sodium pump

Question 28

What is facilitated diffusion and examples of molecules that use this process

Answer 28

When substances are transported across the membrane along the concentration gradient through carrier or channel proteins Examples: glucose and amino acids

Question 29

What is vesicular transport?

Answer 29

Movement of substances across the membrane in vesicles (active process)

Question 30

What is endocytosis, phagocytosis and pinocytosis

Answer 30

Where the membrane folds around a particle to form a vesicle and pinches off, suspended in the cytoplasm. Phagocytosis: solids Pinocytosis: liquids

Question 31

What is exocytosis?

Answer 31

Where a vesicle inside the cell fuses with the cell membrane, and its contents are excreted

Question 32

Why are cells so small?

Answer 32

A large cell would have a smaller Surface Area to Volume ratio, and is unable to transport nutrients throughout the cell efficiently.

Question 33

What is a tissue and its four types

Answer 33

A group of cells that work together to carry out a particular task Epithelial, connective, muscular, nervous

Question 34

What is epithelial tissue, its function, its appearance, and its location

Answer 34

Covering or lining tissue that lines inner surface of tubular organs. Cells are packed closely to form smooth surfaces. Vary in shape - cube or column shaped, flat and thin Found in heart, stomach, intestines, mouth and other hollow organs. Outer layer of skin is epithelial.

Question 35

What is nervous tissue, its function, its appearance, and its location

Answer 35

Made up of neurons that use electrical impulses and chemicals to pass messages around the body Found in brain, spinal cord, nerves

Question 36

What is connective tissue, its function, its appearance, examples, and its location

Answer 36

Supporting tissues that holds/connects body parts together. Characteristics: cell are not closely packed like epithelium, separated by a **matrix** (non cellular material) Examples: bone, cartilage, tendons, ligaments, adipose tissues. Blood is also classified as a connective tissue (matrix is the liquid between blood cells)

Question 37

What is muscular tissue, its function, and its three types

Answer 37

Aka muscle fibres, long, thin tissues that can contract for movement. They are elastic, contractible, extensible and exciteable. Three types are skeletal, smooth and cardiac

Question 38

Describe the characteristics of skeletal muscle (function, appearance, location)

Answer 38

Form of muscular tissue that are attached to bones Voluntary (can control) Striated (have stripes across them)

Question 39

Describe the characteristics of smooth muscle (function, appearance, location)

Answer 39

Form of muscular tissue found in organs such as intestines, stomach, iris, uterus, walls of blood vessels. They contract involuntarily to carry out unconscious processes such as digestion. Non striated.

Question 40

Describe the characteristics of cardiac muscle (function, appearance, location)

Answer 40

Form of muscular tissue that makes up most of the heart, involuntarily contracts to pump blood throughout the body. Striated.

Question 41

Which muscle tissues are striated?

Answer 41

Cardiac and skeletal