Topic 1: Key Concepts in Biology

Question 1

Function of a Nucleus

Answer 1

Contains DNA for a particular protein needed to build new cells. It controls the cell. Enclosed in a nuclear membrane

Question 2

Function of Cytoplasm

Answer 2

Liquid Substance in which chemical reaction occur. Contains Enzymes. Organelles are found in it

Question 3

Function of Cell Membrane

Answer 3

Controls what enters and leaves the cell

Question 4

Function of Mitochondria

Answer 4

Where aerobic respiration reactions occur, providing energy for the cell

Question 5

Function of Ribosomes

Answer 5

Where protein synthesis occurs. Found on a structure called the rough endoplasmic reticulum

Question 6

Function of Chloroplasts

Answer 6

Where photosynthesis takes place providing food for the plant. Contains green pigment called chlorophyll which absorbs light needed for photosynthesis

Question 7

Function of Permanent Vacuole

Answer 7

Contains cell sap. Found within the cytoplasm. Improves cell’s rigidity

Question 8

Function of Cell Wall

Answer 8

Made from Cellulose. Provides strength to the cell

Question 9

Plasmids

Answer 9

Small rings of DNA -Code for extra genes to those provided by chromosomal DNA

Question 10

Flagella

Answer 10

Long, thin ‘whip-like’ tails attached to bacteria that allow them to move

Question 11

Adaptations of Sperm Cells

Answer 11

Streamlined head and long tail to aid swimming
Many Mitochondria to supply the energy to allow the cell to move
The acrosome has digestive enzymes which break down the outer layers of membrane of the egg cell

Question 12

Adaptations of Egg Cells

Answer 12

Surrounded by special cell membrane that only allows one sperm cell to enter-becomes impermeable after.
Lots of mitochondria to provide an energy source for the developing embryo.
Large size and cytoplasm to allow quick, repeated division as the embryo grows

Question 12

Adaptations of Egg Cells

Answer 12

Surrounded by special cell membrane that only allows one sperm cell to enter-becomes impermeable after.
Lots of mitochondria to provide an energy source for the developing embryo.
Large size and cytoplasm to allow quick, repeated division as the embryo grows

Question 13

Specialisation of Xylem cells

Answer 13

Specialised to transport water and mineral ions up the plant from the roots to the shoots

Question 14

Specialisation of Phloem Cells

Answer 14

Specialised to carry the products of photosynthesis to all parts of the plant

Question 15

Parts of a light microscope

Answer 15

Eyepiece lens- The part where we can look through to view specimens
Barrel- The upper part of the microscope that can be moved up or down to focus the image
Lens- The lens increases the magnification of the specimen
Stage- The flat surface on which we place the specimen

Question 16

The Lock and Key Theory

Answer 16

The idea that the shape of the substrate the complementary to the shape of the active site of the enzyme, so when they bond it forms an ES Complex. The reaction takes place and then products are released

Question 17

Enzymes will denature if….

Answer 17

They are not in their optimum temperature or not in their optimum pH

Question 18

Iodine Test

Answer 18

For starch. Turns from orange to blue-black

Question 19

Benedict’s test

Answer 19

For reducing sugars. Turns from blue to reddish brown

Question 20

Biuret Test

Answer 20

For proteins. Turns from blue to purple/pink

Question 21

Emulsion Test

Answer 21

For lipids. Ethanol forms white layer at the top of the sample

Question 22

Calorimetry Equation

Answer 22

E = mass of water4.2Temperature increase