Cell Specialisation And Organisation

Question 1

What is cell specialisation?

Answer 1

• The first group of cells in an embryo are all initially identical. • As it matures each cell takes on its own individual characteristics taht suit it to the function that it will perform when it is mature
• it becomes specialised or differentiated by switching genes on or off

Question 2

What are the 3 ways cells can become specialised by?

Answer 2

1. Changing the shape of the cell
2. Changing the number of a specific organelle
3. Changing the plasma membrane

Question 3

What are the adaptations of erythrocytes?

Answer 3

• biconcave shape - increase SA:Vol and allows the red blood cell to be flexible
• have no nucleus or other organelles - increases space for haemoglobin therefore more oxygen can be transported

Question 4

What are the adaptations of a sperm cell?

Answer 4

• acrosome - structure taht forms a cap over most of the nucleus of the sperm cell. Contains enzymes to digest through the outer membrane of the egg so the sperm can get in
• contains many mitochondria - release ATP to provide energy for the whipping motion
• contains a haploid nucleus- which contains the genetic info from the father
• tail is a long, whip like cellular appendage that is used for locomotion. Uses its tail in a while like fashion lashing it back and forth to propel the sperm forward

Question 5

What is the order of how organ systems are made?

Answer 5

Question 6

What are tissues?

Answer 6

Collection of cells taht are similar to each other and perform a similar function

Question 7

What are organs?

Answer 7

Collection of tissues that work together to perform a particular function

Question 8

What are organ systems?

Answer 8

Group of organs working together
Eg respiratory system

Question 9

What are squamous epithelium?

Answer 9

•Flattened cells
•Very thin
•Line the inside of blood vessels and tubes to provide smooth surface for passage of fluids
•Thin walls to provide a short diffusion pathway
Eg found in alveoli in the lungs to allow for efficient exchange for oxygen and carbon dioxide

Question 10

What are ciliated epithelial tissues?

Answer 10

• made up of column shaped cells
• found on inner surface of the tubes eg trachea, bronchi, oviducts, bronchioles, uterus
• goblet cells produce and secrete mucus (mucus traps pathogens)
• cilia waft mucus when they move in a synchronised rhythm out of the lungs to the back of the throat where it enters the oesophagus and drops into the stomach (pathogen destroyed by stomach acid)
• nicotine can paralyse cilia and tag can damage them so they can’t sweep mucus out