Key Concepts in biology - Year 9

What's the definition of Cell Membrane?

It's a structure that controls what enters and exits the cell.

Whats the definition of the Nucleus

It's a structure that controls the activities of the cell, and contains genetic material ( DNA)

Whats the definition of Mitochondria?

Its a structure where aerobic respiration takes place, which releases energy.

What are ribosomes?

The Structure where protein synthesis takes place and new proteins are made.

What is Chloroplast

The structure where photosynthesis takes place and which produces food for plants.

What is the definition of a vacuole

The structure which is filled with cell sap, which produces structure for the cell

What is the Cell Wall?

The structure that provides structure and support for the cell

Where is the nucleus found?

In both animal and plant cells

In which type of cell is the cell wall found?

It is only found in plant cells

Where are chloroplasts found?

only in plant cells

In which type of cells are mitochondria : found?

In both animal and plant cells

Where is the cell membrane found?

In both animal and plant cells

In which type of cells is the vacuole found?

Only in plant cells

Where are ribosomes found?

In both animal and plant cells

What cell structure surrounds every cell?

Cell Membrane

What gas do animal cells need to take : into the cell?

Oxygen

What gas do plant cells need to take into the cell?

Carbon dioxide

By what process do gases move into cells?

Diffusion

What is osmosis ?

Movement of water from high water concentration to low water concentration through a partially-permeable membrane

Where does water want to move in relation to solute concentration?

To where there is less water and more solute

What is a solute?

Something that dissolves in water, such as salt or sugar

What is the formula for percentage change in mass?

Percentage change= final mass - initial mass divided by initial mass x 100

If the starting mass is 8g and the final mass is 3g, what is the percentage change in mass?

62.5%

What is the definition of diffusion?

The movement of particles from an area of high concentration to a low concentration

Does diffusion require energy?

No, it occurs until equilibrium is reached

What is the net movement of particles in

diffusion?

From an area of high concentration to low concentration

In what states of matter does diffusion : occur?

liquids and gases

What are the key characteristics of diffusion?

Movement from high to low concentration

Does not require energy

Occurs in liquids and gases

Continues until equilibrium is reached

What do bacterial cells contain that is not found in eukaryotic cells?

Plasmids

What are three features of a bacterial

cell?

No nucleus / chromosomal DNA, Has a cell wall, Has flagellum

Where on a sperm cell is the acrosome found?

In the head

How do flagella help bacteria in their movement?

They can rotate or move in a whiplike motion

What is the function of the cell wall in bacterial cells?

To provide structure and protection

How does the composition of plant cell walls differ from bacterial cell walls?

Only plant cell walls are made from cellulose

What is the role of the acrosome in a sperm cell?

It contains enzymes to digest the egg

What is the function of the jelly coat: surrounding an egg cell?

It stops more than one sperm cell entering

Why does a sperm cell have a lot of mitochondria?

To release energy, so it can swim to the egg

What is the function of the ciliated cell in the oviduct?

To waft an egg from the ovary to the uterus

Why does a sperm cell have a tail?

To swim to the egg cell

What is the function of the ciliated cell in the trachea/ bronchi?

To waft any pathogens/ dirt trapped in the mucus back up to the throat

What effect does tar in cigarettes have : on cilia?

It destroys the cilia, and stops the cell from working

What type of cells are animals made up of?

Eukaryotic cells

They have a nucleus and other structures surrounded by membranes

What is chromosomal DNA in bacterial :

cells?

It is DNA found loose in the cytoplasm

How is chromosomal DNA related to its function in bacterial cells?

It is not contained within a nucleus

What are plasmids in bacterial cells?

Small, closed-circles of DNA present in the cytoplasm

Small, closed-circles of DNA present in the cytoplasm

They can move from one bacterium to another

How do plasmids contribute to variation : in bacteria?

They can move trom one bacterium to another

What is the function of flagella in bacteria?

To move the bacterium