topic 1 (cell biology)

Question 1

eukaryotic cells

Answer 1

cells with a nucleus

Question 2

prokaryotic cells

Answer 2

cells without a nucleus

Question 3

animal cell

Answer 3

ribosomes
nucleus 
cell membrane
mitochondria
cytoplasm

Question 4

plant cell

Answer 4

*everything in an animal cell plus:
chloroplasts
permanent vacuole
cell wall

Question 5

job of nucleus?

Answer 5

controls all the activities in the cell

Question 6

job of ribosomes?

Answer 6

these are where proteins are made in the cell

Question 7

job of cell mem?

Answer 7

controls what goes in and out of cells

Question 8

job of mitochondria ?

Answer 8

where respiration takes place

Question 9

job of chloroplast ?

Answer 9

where photosynthesis takes place

Question 10

job of permanent vacuole ?

Answer 10

contains cell sap and helps to keep plant turgid

Question 11

job of cell wall ?

Answer 11

gives strength to the cell

Question 12

bacteria cell

Answer 12

contains
DNA
plasmids
(+cytoplasm,cell mem and cell wall)

Question 13

DNA

Answer 13

replacement nucleus and hold the genetic material

Question 14

plasmids

Answer 14

small rings of DNA

Question 15

magnification

Answer 15

image size /real size

Question 16

light microscope

Answer 16

uses light and lenses to produce an image (e.g nuclei)

Question 17

electron microscope

Answer 17

uses electrons to form an image , it also has a higher magnification and resolution then a light microscope and lets us see much smaller things

Question 18

chromosomes

Answer 18

body cells contain two of each chromosome and this is found in the nucleus. humans have 23 pairs

Question 19

mitosis

Answer 19

a type of cell division that results in two daughter cells each having the same number and kind of chromosomes

Question 20

stages of mitosis

Answer 20

Interphase The cell spends most of its life in this phase. The DNA in chromosomes copies itself ready for mitosis.
Prophase The DNA in chromosomes and their copies condenses to become more visible. The membrane around the nucleus disappears.
Metaphase Chromosomes and their copies line up in the middle of the cell.
Anaphase Chromosomes and their copies are pulled to different ends of the cell.
Telophase New membranes form around the chromosomes at each end of the cell.
Cytokinesis The cell membrane pinches in and eventually divides into two daughter cells.

Question 21

when does mitosis take place?

Answer 21

mitosis takes place when an organism repairs itself or during asexual reproduction

Question 22

diffusion

Answer 22

movement of molecules from an area of a high conc to an area of a low conc (e.g oxygen out and carbon dioxide in plants )

Question 23

factors affecting rate of diffusion

Answer 23

difference in conc (conc gradient)
temp
SA

Question 24

osmosis

Answer 24

is the diffusion of water from a concentrated solution to a dilute solution through a partially permeable membrane

Question 25

active transport

Answer 25

the movement of particles from an area of low conc to an area of high conc and this process does require energy

Question 26

what is binary fission

Answer 26

the process by which bacteria divides into two every 20 mins number of bacteria=2^(rounds of division)

Question 27

differentiation / specialisation

Answer 27

cells change to become specialised for there job - animal cells loose this ability at an early stage - plant cells never loose this ability

Question 28

examples of specialised cells

Answer 28

``` sperm cells = reproduction nerve cells= rapid signalling muscle cells= contraction root hair cells= water and minerals phloem and xylem =transporting substances ```

Question 29

muscle cells

Answer 29

muscle cells contain protein fibers to help them contract

Question 30

nerve cells

Answer 30

nerve cell axon carries electrical signals ,they are long to cover move distance and have dendrites to connect to other nerve cells

Question 31

sperm cells

Answer 31

sperm cells have a tail to help them swim to the egg the nucleus contains genetic material acrosomes contain enzymes to break into the egg sperm cells also have lots of mitochondria so they have enough energy to swim to the egg

Question 32

root hair cells

Answer 32

provide a large SA to absorb water a dissolve minerals

Question 33

xylem

Answer 33

form long tubes ,these tubes carry water and dissolved minerals from roots to leaves of plants

Question 34

phloem

Answer 34

phloem tubes carry dissolved sugars up and down the plant

Question 35

examples of exchange surfaces

Answer 35

gills have a large SA for gas exchange the structure of leaves lets gases diffuse in and out of cells