biology!

Question 1

what is the function of the nucleus?

Answer 1

contains the genetic information which controls the functions of the cell.

Question 2

what is the function of the cell membrane?

Answer 2

controls what goes in / out of the cell.

Question 3

what is the function of the cytoplasm?

Answer 3

where many cell activities and reactions happen.

Question 4

what is the function of the mitochondria?

Answer 4

provides energy from aerobic respiration.

Question 5

what is the function of ribosomes?

Answer 5

make proteins - site of protein synthesis.

Question 6

what is the function of the chloroplasts?

Answer 6

where photosynthesis occurs.

Question 7

what is the function of the vacuole?

Answer 7

use to store water and other chemicals as cell sap.

Question 8

what is the function of the cell wall?

Answer 8

strengthens and supports the cell (made of cellulose in plants ).

Question 9

what is the function of the DNA loop?

Answer 9

a loop of DNA ( not in a nucleus ).

Question 10

what is the function of the plasmids?

Answer 10

a small circle of DNA, may contain genes associated with antibiotic resistance.

Question 11

name the parts of a microscope…

Answer 11

eyepiece, coarse focus, fine focus, condenser, stage, stage clips, arm, mirror and objective lenses.

Question 12

formula to calculate magnification is…

Answer 12

magnification = image size / actual size.

Question 13

resolution definition:

Answer 13

the ability to distinguish between two points on an image.

Question 14

calculate magnification of an object that is 0.05 micrometres long but has an image size of 0.8mm long.

Answer 14

1. figure out 0.8mm into micrometres.
   = 800 micrometres.
2. substitute 800 micrometres and 0.05 micrometres into the calculation: image size / actual size.
   = 800 / 0.05 = 16,000x
   remember to use the unit “x”.

Question 15

order of how to set up a specimen on a microscope:

Answer 15

1. make sure the objective lens with the lowest power is in use.
2. secure the specimen on the stage using the clips.
3. adjust the mirror to focus light onto the specimen.
4. observe through the eyepiece and manually focus using the coarse focus knob.
5. switch to a higher magnification.
6. manually focus using the fine focus knob.

Question 16

what are stem cells?

Answer 16

all cells in our body are derived from stem cells. these cells are very simple cells without any adaptations.

Question 17

eg. of specialised cells:

Answer 17

red blood cells ( without nucleus ).

Question 18

what does iron make?

Answer 18

haemoglobin.

Question 19

what is haemoglobin?

Answer 19

the protein contained in red blood cells that is responsible for the delivery of oxygen to the tissues.

Question 20

what are specialised cells?

Answer 20

cells with specific features to perform a particular function.

Question 21

what is differentiation?

Answer 21

the process when stem cells specialise, and differentiate to perform their function.

Question 22

eg. of differentiation:

Answer 22

stem cells —-> muscle cells ( for movement )
stem cells —-> blood cells ( for transporting oxygen )

Question 23

what is the function of the red blood cells’ biconcave shape?

Answer 23

increases the surface area to take in oxygen. There is no nucleus so there is more room to hold haemoglobin.