Topic 1 cells

Question 1

prokaryotic

Answer 1

cells without a nucleus and are smaller and are a

simpler cell

Question 2

eukaryotic

Answer 2

cells with a nucleus and are more complex such as all animal and plant cells also made of eukaryotic cells

Question 3

prokaryote

Answer 3

a singled celled organism

Question 4

nucleus

Answer 4

contains genetic material and controls the activities of the cell

Question 5

cytoplasm

Answer 5

jelly like substance where the chemical reactions take place it also contains enzymes that control the reactions

Question 6

cell membrane

Answer 6

holds the shape of the cell together and controls what enters the cell and what exits the cell

Question 7

mitochondria

Answer 7

where the aerobic reactions take place respiration also transfers energy that the cell needs to work

Question 8

ribosomes

Answer 8

where the proteins for the cells are created

Question 9

cell wall

Answer 9

made of cellulose supports the cell and strengths it

Question 10

vacuole

Answer 10

contains cell sap a solution of sugar and salts

Question 11

chloroplast

Answer 11

where photosynthesis happens which makes the food for the plant

Question 12

chlorophyll

Answer 12

a green substance found in chloroplast and absorbs the sunlight for photosynthesis

Question 13

plasmids

Answer 13

rings of DNA

Question 14

differentiation

Answer 14

the process when a cell becomes specialised for it’s job

Question 15

stem cells

Answer 15

undifferentiated cells they can become any cell in the body

Question 16

sperm cells

Answer 16

used for reproduction rounded head to penetrate the egg cell and a tail to swim to it has lots of mitochondria because it needs the energy to do its job enzymes in the head to digest through the egg cells membrane

Question 17

nerve cells

Answer 17

used for rapid signalling carries electrical signals from one part to another in the body the cells are long to cover long distances this forms a network throughout the body

Question 18

muscle cells

Answer 18

used for contraction cells are long so have space to contract contains lots of mitochondria for the energy needed to contract

Question 19

root hair cells

Answer 19

used for absorbing water and minerals have a large surface area and look like a large hair sticking into the soil so they can absorb more water and minerals

Question 20

phloem

Answer 20

transports food mostly sugars the transport goes both ways and is called translocation

Question 21

xylem

Answer 21

takes up water made of dead cells joined together carries water and mineral ions which come from the roots, stem and leaves the water moved up through the plant and this is called transpiration system

Question 22

chromosomes

Answer 22

coiled up lengths of DNA molecules chromosomes carry lots of genes and these give us our charactristics

Question 23

chromosomes in a human

Answer 23

23 pairs of chromosomes one from the mother and one from the father

Question 24

body cells

Answer 24

divide in multicellular organisms producing more cells and part of the cell cycle

Question 25

mitosis

Answer 25

when cells divide to grow or replace old or damaged cells ends with two identical cells with 23 pairs of chromosome

Question 26

cell cycle

Answer 26

before a cell divides it has to duplicate a number of mitochondria and ribosomes and increase the size of the cell

Question 27

binary fission

Answer 27

the circular DNA replicate so the cells get bigger and the circular data move to the two poles of the cell the cytoplasm begins to divide and the new cell walls begin to form them it divides into two cells each has one circular DNA but has a random number of plasmids

Question 28

stem cells locations

Answer 28

embryos have many and adults have them in their bone marrow

Question 29

diseases cured by stem cells

Answer 29

diabetes, paralysed by spinal injuries because it can replace the bad genes with the good ones also they are being used for cloning

Question 30

against stem cells research

Answer 30

requires embryos to be destroyed after extracting the stem cells

Question 31

stem cells in plants

Answer 31

used to grow in the meristems as they are undifferentiated until they are needed so they can also create clones of themselves

Question 32

diffusion

Answer 32

movement of particles from high concentration to low concentration happens in gases and liquids the bigger the difference in concentration(concentration gradient) the faster the diffusion is the higher the temperature also makes it diffuse faster

Question 33

osmosis

Answer 33

the movement of water of molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration

Question 34

active transport

Answer 34

the root hair cells have a large surface area so more minerals can be absorbed the concentration is greater inside the root hair cell so it is going from low concentration to high and is called active transport

Question 35

active transport in the body

Answer 35

there is a low concentration of nutrients in the gut and a higher concentration in the blood when there is a higher concentration in the gut it will diffuse but if it is lower, then active transport needs to transport the nutrients as diffusion can’t

Question 36

exchanging surfaces

Answer 36

how easily things move between organisms and its environment depending on the surface area to volume ratio