year 9 cells- assessment week

Question 1

what are mitochondria?

Answer 1

small organelles found in animal and plant cells

Question 2

what is the function of mitochondria?

Answer 2

site of respiration

Question 3

what is a ribosome?

Answer 3

tiny organelle found in animal and plant cells

Question 4

what is the function of the ribosome?

Answer 4

making proteins

Question 5

what is a membrane bound organelle?

Answer 5

an organelle with its own membrane

Question 6

give 3 examples of membrane bound organelles.

Answer 6

nucleus, mitochondria, chloroplast

Question 7

what is a eukaryotic cell?

Answer 7

cells that have membrane bound organelles

Question 8

in a eukaryotic cell, where is DNA found?

Answer 8

in the nucleus

Question 9

give 2 examples of eukaryotic cells.

Answer 9

animal and plant cells

Question 10

what is a prokaryotic cell?

Answer 10

cells that have no membrane bound organelles

Question 11

give an exmaple of a prokaryotic cell.

Answer 11

bacteria cell

Question 12

what is a plasmid?

Answer 12

a tiny loop of DNA

Question 13

what is cell differentiation?

Answer 13

the process by which a cell becomes specialised

Question 14

what are stem cells?

Answer 14

undifferentiated cells

Question 15

where are the stem cells found in plants?

Answer 15

meristematic regions

Question 16

where are stem cells found in animals?

Answer 16

bone marrow and embryos

Question 17

how do you calculate magnification?

Answer 17

magnification= image size/ actual size

Question 18

what does focus mean?

Answer 18

making an image sharp enough to be viewed

Question 19

how do you focus an image using microscope?

Answer 19

by turning the focussing knob

Question 20

how do you record an image from a microscope?

Answer 20

draw what can be seen through the eyepiece

Question 21

what is resolution?

Answer 21

the ability to distinguish between two points

Question 22

which type of microscope has the highest resolution?

Answer 22

an electron microscope

Question 23

what is the maximum magnification of a light microscope?

Answer 23

about x2,000

Question 24

what is the maximum magnification of an electron microscope?

Answer 24

about 2,000,000

Question 25

what is the name of the specialised cell carrying male DNA for reproduction?

Answer 25

sperm cell

Question 26

why does a sperm cell contain many mitochondria?

Answer 26

to provide energy from respiration for swimming

Question 27

why does a sperm cell have a long tail?

Answer 27

to swim to the egg

Question 28

what is found in the acrosome in the head of the sperm?

Answer 28

digestive enzymes

Question 29

why does the sperm head contain digestive enzymes?

Answer 29

to break down the wall of the egg cell

Question 30

what is the name of the specialised cell in the stem of the plant carrying water?

Answer 30

xylem

Question 31

how is a xylem cell specialised?

Answer 31

dead hollow tubes, rings of lignin

Question 32

what is the name of the specialised cell in the stem of the work transporting sugar?

Answer 32

phloem

Question 33

how is phloem cell specialised?

Answer 33

supported by companion cells, sieve plates between cells

Question 34

what is diffusion?

Answer 34

the net movement of particles in a fluid from an area of high concentration to an area of low concentration

Question 35

give two exmaples of diffusion in the human body

Answer 35

gas exchange in lungs, absorption in the small intestine

Question 36

what is a concentration gradient?

Answer 36

a difference in concentration between two regions

Question 37

what four factors affect the rate of diffusion?

Answer 37

temperature, concentration gradient, surface area, diffusion distance

Question 38

what is the effect of increased temperature on rate of diffusion?

Answer 38

increased

Question 39

what is the effect of increased surface area on rate of diffusion?

Answer 39

increased

Question 40

what is the effect of increased diffusion distance on rate of diffusion?

Answer 40

decreased

Question 41

what is a partially permeable membrane?

Answer 41

a membrane which only allows certain substances to cross

Question 42

what is osmosis?

Answer 42

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

Question 43

what is an isotonic solution?

Answer 43

concentration of solutes is the same as in the cytoplasm

Question 44

What is a hypotonic solution?

Answer 44

Concentration of solutes is less than in the cytoplasm

Question 45

What is a hypertonic solution?

Answer 45

Concentration of solutes is more than in the cytoplasm

Question 46

What is the direction of osmosis for cells in hypotonic solutions?

Answer 46

Water moves into the cell

Question 47

What happens to plant cells in hypotonic solutions?

Answer 47

Become turgid

Question 48

What happens to animal cells in hypotonic solutions

Answer 48

Lysis (cells burst)

Question 49

What is the direction of osmosis for cells in hypertonic solutions?

Answer 49

Water moves out of the cell

Question 50

What happens to animal cells in hypertonic solutions?

Answer 50

Become crenated (shrivelled)

Question 51

What happens to plant cells in hypertonic solutions?

Answer 51

Plasmolysis

Question 52

What is plasmolysis?

Answer 52

Cell membrane shrinks away from cell wall

Question 53

What is active transport

Answer 53

The movement of substances across the cell membrane, against a concentration gradient

Question 54

What is required for active transport to occur?

Answer 54

Energy from respiration

Question 55

Give two examples of active transport

Answer 55

Absorption of minerals by plant root hairs and absorption of sugar in the blood

Question 56

What is the relationship between size and surface area to volume ratio?

Answer 56

As size increases, surface area to volume ratio decreases

Question 57

How do large organisms overcome the problem of having a small surface area to volume ratio?

Answer 57

By having specialised exchange surfaces