b1 - cell biology

Question 1

eukaryotic cell

Answer 1

cell that contains a clearly defined nucleus and membrane-bound organelles

Question 2

prokaryotic cell

Answer 2

cell that doesn’t have a true nucleus or membrane-bound organelles

Question 3

eukaryote

Answer 3

organisms made of eukaryotic cells

Question 4

prokaryote

Answer 4

prokaryotic cell (single-celled organism)

Question 5

nucleus

Answer 5

contains genetic material; controls activities of the cell

Question 6

cytoplasm

Answer 6

gel-like substance where most chemical reactions occur

Question 7

cell membrane

Answer 7

holds cell together; controls what substances leave and enter the cell

Question 8

mitochondria

Answer 8

where most of reactions for aerobic respiration take place

Question 9

ribosomes

Answer 9

where proteins are made in the cell

Question 10

cell wall (plants only)

Answer 10

made of cellulose; supports and strengthens the cell

Question 11

vacuole (plants only)

Answer 11

contains cell sap

Question 12

chloroplasts

Answer 12

where photosynthesis occurs - contains green substance called chlorophyll which absorbs light

Question 13

plasmid (bacterial cell)

Answer 13

small ring of DNA floating in the nucleus

Question 14

microscope

Answer 14

instrument used to examine objects that are too small for the naked eye to see

Question 15

light microscope

Answer 15

microscope that uses light/lenses to form an image of a specimen and magnify it

Question 16

electron microscope

Answer 16

microscope that uses electrons to form an image
has a higher magnification and resolution than a light microscope

Question 17

magnification

Answer 17

how many times larger an image is than the actual object

magnification = image size / actual size

Question 18

cell differentiation

Answer 18

process by which a cell changes to become specialized for its job

Question 19

sperm cells

Answer 19

specialized for reproduction

long tail and streamlined head to allow it to swim
lots of mitochondria to provide energy needed
carries enzymes in its head to digest through egg cell membrane

Question 20

nerve cells

Answer 20

specialized for rapid signalling

long to cover more distance
have branched connections at their ends to connect to other nerve cells and form a network

Question 21

muscle cells

Answer 21

specialized for contraction

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

Question 22

root hair cells

Answer 22

specialized for absorbing water and minerals

on the surface of plant roots to grow into long hair that stick out into soil
gives plant a big surface area for absorbing water/mineral ions

Question 23

phloem and xylem cells

Answer 23

specialized for transporting substances

cells are joined end to end to form tubes
xylem cells hollow in centre so stuff can flow through
phloem cells have very few sub-cellular structures so stuff can flow through

Question 24

chromosomes

Answer 24

coiled up lengths of DNA molecules
23 pairs in the human body (sex chromosomes - XY for men and XX for women)

Question 25

genes

Answer 25

segments of DNA which control the development of different characteristics

Question 26

cell cycle

Answer 26

series of stages in a cell’s life for growth, repair and development of the cell’s life