B1

Question 1

Nerve cell

Answer 1

Send electrical impulses around the body
Long to cover more distance, has branched connections

Question 2

Muscle

Answer 2

To contract quickly
Long and contains lots of mitochondria (for energy)

Question 3

Sperm cell

Answer 3

To get male DNA to the female DNA
Streamlined head, long tail, lots of mitochondria (for energy)

Question 4

Root hair cell

Answer 4

Absorb water from the soil
A large surface area to absorb more water

Question 5

Phloem cell

Answer 5

Transports substances around the plant
Pores to allow cell sap to flow
Cells are long and joined end to end

Question 6

Xylem cell

Answer 6

Transports water through the plant
Hollow in the centre. Tubes are joined end to end

Question 7

What is diffusion

Answer 7

The spreading out of particles from an area of higher concentration to an area of lower concentration.

Question 8

Osmosis

Answer 8

The movement of water molecules from an area of high concentration to a low concentration through a partially permeable membrane.

Question 9

Active transport

Answer 9

Movement of substances against the concentration gradient. Requires energy from respiration.

Question 10

Equation for image size

Answer 10

Image size = actual size x magnification

Question 11

Osmosis and potato practical

Answer 11

Potato in sugar solution lose water
Potato in pure water solution will gain water

Question 12

Where are adult stem cells found

Answer 12

In the bone marrow

Question 13

Use for stem cells

Answer 13

• replacing faulty blood cells
• making insulin producing cells
• making nerve cells

Question 14

What is the equation for magnification of the microscope

Answer 14

Magnification of eyepiece x magnification of objective

Question 15

What do ribosomes do

Answer 15

The site of protein synthesis

Question 16

What do mitochondria do

Answer 16

Where aerobic respiration takes place

Question 17

What is the cytoplasm

Answer 17

Jelly-like material where many of the chemical reactions happen

Question 18

What is the nucleus

Answer 18

Contains genetic material
Controls the cell’s activities

Question 19

What is the cell membrane

Answer 19

Structure permeable to some substances but not to others. Controls movement in and out of cells

Question 20

What are chloroplasts

Answer 20

Organelles which contains the green pigment chlorophyll, which absorbs light energy for photosynthesis

Question 21

What is the cell wall

Answer 21

Strengthens cell and supports the plant

Question 22

What is a permanent vacuole

Answer 22

Filled with cell sap to help keep the cell turgid

Question 23

What is and give example of prokaryotic cell

Answer 23

A simple cell with no nucleus- DNA is free in cytoplasm
Example: bacterial cell

Question 24

What is and give example of eukaryotic cell

Answer 24

A type of cell that has a nucleus
Plant/animal/fungi cells

Question 25

What are chromosomes

Answer 25

Carry genetic information in a molecule called DNA Each section of a chromosome that contains the code for the production of a particular protein is called a gene

Question 26

How many chromosomes do humans have

Answer 26

46 23 pairs

Question 27

Difference between male and female chromosomes is

Answer 27

23rd pair Female = XX Male = YY

Question 28

When do cells divide

Answer 28

An organism grows An organism becomes damaged and needs to produce new cells

Question 29

Where is DNA in a cell

Answer 29

In a cell’s nucleus in structures called chromosomes

Question 30

What is the cell cycle stages

Answer 30

Cell growth DNA synthesis- the chromosomes are now double stranded Further growth occurs and the DNA is checked for errors Mitosis The cytoplasm separates- two cells are formed Temporary cell resting period or the cell stops dividing

Question 31

What are the steps for mitosis

Answer 31

The cell begins to divide The DNA replicates to form two copies of each chromosome The nuclear membrane breaks down. The chromosomes line up across the centre of the cell One set of chromosomes is pulled to each end of the cell and the nucleus divides The cytoplasm and cell membrane divide to form two identical cells

Question 32

What are daughter cells

Answer 32

When a cell divides, the new cells produced is called daughter cells

Question 33

What examples of diffusion are in biological systems

Answer 33

Leaf - photosynthesis Lungs -air in + out Liver cells - urea

Question 34

What is the rate of diffusion effected by

Answer 34

Concentration gradient Temperature Surface area of cell membranes

Question 35

What is osmosis

Answer 35

The movement of water molecules across a selectively permeable membrane from a region of higher water concentration to a region of lower water concentration