bacteria and specialised cells

Question 1

Genetic material

Answer 1

bacteria DO NOT have a nucleus, instead, the cytoplasm contains one large loop of chromosomal DNA which controls most of the cell’s activities. there are also smaller oops of DNA called plasmids and they control a few of the cell’s activities.

Question 2

light microscope

Answer 2

bacteria are difficult to see with a light microscope because they are very small and mostly colourless so stains are often used to make them show up

Question 3

flagellum

Answer 3

is not covered in a membrane and not all bacteria have them but some have many. they help the bacteria to move around

Question 4

slime coat

Answer 4

for protection

Question 5

flexible cell wall

Answer 5

for support (is NOT made of cellulose)

Question 6

cell membrane

Answer 6

cell membrane controls what enters and leaves the cell.
its a semi permeable membrane that only lets some things in and some out.
it is like a very thin bag.

Question 7

what are specialised cells

Answer 7

they are cells that have a specifc function (job)
they all have the same basic structure but their sizes, shapes and sub-cellular structures can be different so that specialised cells adapted to their function.

Question 8

specialised cells for digestion (1)

Answer 8

cells that line the small intestine are adapted by having membranes with many tiny folds to increase the surface area of the cell so absorption happens faster.

Question 9

specialised cells for digestion (2)

Answer 9

cells i teh pancrease make enzymes to digest certain foods and these enzymes are proteins and are adapted by having many ribosomes.

Question 10

specialised cells for reproduction (1)

Answer 10

• sperm cells have a flagellum which helps them swim to the egg cell to fertillise it
• it has a spiral of mitochondria in the middle section to fuel it with lots of energy so it can last until it makes it to the egg cell
• lastley it has an acrosome at the top of its head which contain enzymes that can breakdown the cell membrane/jelly coat around the egg cell to fertillise it
• has a haploid nucleus

Question 11

specialised cells for reproduction (2)

Answer 11

• the egg cell is adapted by having lots of nutrients in its cytoplasm for the future embryo (for growth and development)
• after it has been fertilised by one sperm cell, the cell membrane/jelly coat hardens so it cannot be fertillised again by another sperm cell
• has a haploid nucleus which means it contains only one set of chromosomes

Question 12

specialised cells for digestion (3)

Answer 12

The wall of the small intestine has muscles to squeeze food along. These cells require a lot of energy and are adapted by having many mitochondria.

Question 13

prokaryotic cells

Answer 13

bacteria are prokaryotic because they dont have a nucleus and they don’t have mitochondria or chloroplasts