Lecture 1 Quiz 1

Question 1

Define Homeostasis

Answer 1

The body’s internal balance / equilibrium that is controlled by internal regulators - it controls such things as body temperature, the ph level, glucose levels, blood pressure, water and enzyme levels and finally blood and tissue ie O2 and CO2 levels and the internal control mechanisms ensure certain facets lie within within tightly controlled ranges eg temperature - the ideal range is 36.5-37.5C

Question 2

Briefly explain how a negative feedback system works

Answer 2

A disruptor is detected by a receptor / detector and a message is sent to the control centre who engages an effector to respond. eg the body temperature raises - the effect is to col the body to stop sweating etc

The output reverses the input

Question 3

Describe the structure of the cell membrane

Answer 3

Aa semi permeable phospholipid bilayer that separates the cells’ internal and external environment

Phosphate heads to outer edge and they are hydrophilic - water loving and with the lipids (fats) with the tails pointing inwards - they are hydrophobic - ie water hating.

The membrane has transmembrane proteins embedded within

It allows for substances to pass in and out of the cells

Question 4

What is meant by the term hydrophilic?

Answer 4

Water loving

Question 5

How many chromosomes does a human somatic cell have?

Answer 5

46 or 23 pairs

Question 6

Describe the main function of ribosomes?

Answer 6

Protein synthesis for inside and outside of the cell

Question 7

Name the cell organelle involved in energy (ATP) production

Answer 7

Mitochondria

Question 8

Name the cell organelle that modifies, sorts and packages proteins

Answer 8

Golgi Apparatus

Question 9

State ONE function of lyosomes

Answer 9

Recycling of worn out organelles - they engulf, digest and return the components to the cytosol for re-use