Cell structure

Question 1

What do both forms of cells consist of?

Answer 1

Cell membrane
Cytoplasm
Ribosomes

Question 2

What plant spesific organells are there?

Answer 2

Cell wall
vacuole
Chlorolplasts

Question 3

What are bacteria cells?

Answer 3

Prokaryotes

Question 4

What are the organelles of bacteria cells?

Answer 4

Cell membrane
ribosomes
cell wall
circular strand of dna (plasmids)
Cytoplasm

Question 5

Why do we estimate the size of cells?

Answer 5

to small to directly measure size

Question 6

What are the different specilised cells?

Answer 6

sperm 
nerve
muscle
root hair cell
xylem
phloem

Question 7

How is sperm specilisied?

Answer 7

head of the sperm contains the genetic material for fertilisation
middle piece is packed with mitochondria to release energy needed to swim and fertilise the egg
tail enables the sperm to swim.

Question 8

How are nerve cells specilisied?

Answer 8

nerve cell is extended, so that nerves can run to and from different parts of the body to the central nervous system

Question 9

How are muscle cells specilisied?

Answer 9

contain filaments of protein that slide over each other to cause muscle contraction
mitochondria to provide the energy for muscle contraction

Question 10

How are root hair cells specilisied?

Answer 10

large surface area to provide contact with soil water. It has thin walls so as not to restrict the movement of water.

Question 11

How are xylem cells specilisied?

Answer 11

no top and bottom walls between xylem vessels, so there is a continuous column of water running through them
Their walls become thickened and woody. They therefore support the plant.

(made of dead cells)

Question 12

How are phloem cells specialised?

Answer 12

• Sieve tubes - specialised for transport and have no nuclei. Each sieve tube has a perforated end so its cytoplasm connects one cell to the next.
• Companion cells - transport of substances in the phloem requires energy. One or more companion cells attached to each sieve tube provide this energy.

(made of living cells)

Question 13

What are genes?

Answer 13

Short sections of DNA which code for building proteins - characteristcs

Question 14

What is a geneome?

Answer 14

The entire genetic material of an organism

Question 15

What is a mutation?

Answer 15

A change in the gene, chromosome or DNA sequence

Question 16

3 reasons we study the human genome?

Answer 16

Search for genes which are linked to disease
Unserstanding the human genome will help treat inherited disorders
We can trace human migration patterns from the past

Question 17

What is the process of meisosis?

Answer 17

Cell from testies or ovaries (46 chromosomes)
1 - DNA replicates
2 - Cell divides twice
3 - 4 daughter cells form - gentically different - contain a single set of chromosomes

Question 18

What is the equation for binary fission?

Answer 18

Starting population X2 to the power of number of divisions

Question 19

How often does bacteria normally replicate?

Answer 19

Every 20 minutes by binary fission

Question 20

What does binary fission depend on?

Answer 20

availability of nutrients and other suitable conditions, such as temperature.

Question 21

What are two ways to grow or culture bacteria

Answer 21

nutrient broth solution or colonies on an agar plate

Question 22

What does Nutrient broth solution do?

Answer 22

It allows a liquid or gel to provide all the nutrients needed for bacteria to grow successfully.

Question 23

What nutrients are needed for Nutrient broth solution, or culture medium?

Answer 23

carbohydrates for energy, nitrogen for protein synthesis, plus other minerals

Question 24

How is an agar plate created?

Answer 24

By pouring hot molten agar into sterile petri dishes, which is then allowed to set

Question 25

What can you use to transfer bacteria?

Answer 25

An inoculating loop

Question 26

How do you sterilise an inoculating loop?

Answer 26

By heating it to red hot in a Bunsen flame, before and after use.

Question 27

What does the lid on the petri dish do?

Answer 27

the lid prevents micro-organisms from the air contaminating the culture

Question 28

How do you inoculate an agar plate

Answer 28

lift the lid of the Petri dish and tilt

Question 29

At what temperature are Inoculated agar plates incubated at? For how long?

Answer 29

25°C in school laboratories for no more than 24–48 hours.

Question 30

What is a prokaryotic cell?

Answer 30

A simple cell that does not have a nucleus – the DNA is free in the cytoplasm. (made up of prokaryotic cells)

Question 31

What is a eukaryotic cell?

Answer 31

A type of cell that has a nucleus. (made up of eukaryotic cells)

Question 32

What are plasmids?

Answer 32

small rings of DNA

can replicate

Question 33

Do prokaryotes contain mitochondria?

Answer 33

No

Question 34

What is the process to prepare an uncontaminated culture?

Answer 34

Pre inoculation:

• Petri dish and agar sterilised before use to kill unwanted bacteria
• Inoculating loop passed through flame to sterilise/kill other bacteria

Inoculation:

• Use loop to spread bacteria on agar
• Open as little as possible to prevent microbes entering from air

Post inoculation:

• Sealed with tape
• Incubate

Question 35

What is the zone of inhibition?

Answer 35

area in which ecoli has been destroyed/no longer growing

Question 36

What is the process of mitosis?

Answer 36

1) DNA replicates to form 2 copies of each chromosome
2) Sub celleur structures multiply
3) Cells grow
4) Sub celleur structures pulled to each side of the cell
5) Chromosomes and their copies seperateand then cell dividies

Question 37

What is the name for cell division?

Answer 37

Cytokinesis

Question 38

What are the results of mitosis?

Answer 38

• 2 daughter cells

- Genetically identical

Question 39

What can mitosis be used for in terms of cells?

Answer 39

• Repair
• Development
• Growth