B2.1 Supplying the cell

Question 1

Active transport

Answer 1

Movement of molecules against their concentration gradient

Question 2

Cell cycle

Answer 2

The process of cell growth and division

Question 3

Concentration gradient

Answer 3

Difference in concentration between two regions

Question 4

Differentiation

Answer 4

Conversation of cell from unspecialised to specialised

Question 5

Diffusion

Answer 5

Net movement of particles from a region of high concentration to a region of low concentration

Question 6

DNA replication

Answer 6

Process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules

Question 7

Meristems

Answer 7

Growing region of a plant

Question 8

Mitosis

Answer 8

Process by which body cells divide

Question 9

Osmosis

Answer 9

Diffusion of water molecules from a region of high concentration to an area of low concentration through a selectively permeable membrane

Question 10

Specialised

Answer 10

A cell that is adapted to preform a particular function is called a specialised cell

Question 11

Stem cell

Answer 11

Undifferentiated cell; two main types: adult stem cells and embryonic cells

Question 12

Embryonic cells

Answer 12

found in embryos. They divide by mitosis to produce all the cells needed to make an organism. Embryonic cells have the ability to differentiate into all cell types.

Question 13

Adult stem cells

Answer 13

Found in various body tissues such as the brain, bone marrow, skin and liver. They are able to differentiate into specific types of cells, so not as much as embryonic cells. They are used as a repair mechanism for the body.

Question 14

Sperm cells

Answer 14

A sperm cell is specialised to transfer genetic material from the male to ovum. Its adaptation include: flagellum (to move to the ovum), lots of mitochondria (the energy produced in respiration transferred to the flagellum can move), acrosome (stores digestive enzymes that break down layers of the ovum)

Question 15

Fat cell

Answer 15

Fat cells are specialised to store fat (store of energy). They are adapted by having a small layer of cytoplasm surrounding the fat reservoir.

Question 16

Red blood cells

Answer 16

They specialised to transport oxygen around the body. Adaptions include their biconcave disc shape (increases the surface area-speeds up diffusion). Has no nucleus and is filled with haemoglobin.

Question 17

Ciliated cells

Answer 17

They are located in your airways. In between these cells are goblet cells, which produce sticky mucus (which traps dirt and bacteria).

Question 18

Palisade cells

Answer 18

they are specialised for carrying out photosynthesis. They are packed with chloroplasts, have maximum absorption of sunlight and are found near the surface of the leaf.

Question 19

Chromosome movement

Answer 19

Second stage of the cycle. The chromosomes line up across the centre of the cell. The two identical copies of the cell separate and move to opposite ends of the cell. Now each end have a full set of identical chromosomes, two nuclei form.

Question 20

Cytokinesis and development of the daughter cells

Answer 20

The third stage is where the cell membrane pinches inwards to separate the two new nuclei, and then pinches off to split the original cell into two genetically identical daughter cells. this process is called cytokinesis. Then each of the daughter cells will then grow independently and the cycle will continue.

Question 21

Cell cycle

Answer 21

The process of cell growth and division

Question 22

What are carrier proteins? (Used in active transport)

Answer 22

Special proteins that span across the width of the cell membrane.
A particular molecule that the cell requires binds to a specific carrier protein. Energy is transferred from an energy store to the protein so it can change shape or rotate. Then the carrier protein transports the molecule into the cell.

Question 23

Percentage change

Answer 23

New result- original result
———————————- x 100
Original result

Question 24

What affects the rate of diffusion?

Answer 24

Distance, concentration gradient, and surface area.