Biology - Key concepts in biology

What is a cell

It is the basic unit of living organisms

What are the 2 different types of cell

Eukaryotic and prokaryotic cells

What is an eukaryotic cell

They are complex cells that contain a nucleus and other membrane-bound organelles

Where are eukaryotic cells found

They are found in multicellular organisms like animal, plants and fungi

What is a prokaryotic cell

A simple, single-celled organism lacking a nucleus and other membrane-bound organelles.

Where are prokaryotic cells found

They are found in bacteria and archaea

Features of prokaryotic cells

• They may have one or more small rings of DNA called plasmids

• These plasmids can replicate and move between cells

• They do not have a nucleus or membrane bound organelles

• Most of their genetic material is stored in a single DNA loop in the cytoplasm

What are sub-cellular structures

They are structures found in a cell

What is a cell membrane

It separates the inside of the cell from the environment outside and controls substances moving in and out of the cell

What is a nucleus

It contains chromosomes which contains the genetic materials

What are ribosomes

They are responsible for making proteins

What is a mitochondria

It is where aerobic respiration takes place

What is an aerobic respiration

It is a process which uses glucose and oxygen to release energy

What is a cytoplasm

It is a jelly-like fluid that fills the cell and is where most of the cell’s chemical reactions take place

List sub-cellular structures found in an animal cell

• Cell membrane

• Nucleus

• Ribosomes

• Mitochondria

• Cytoplasm

List common types of animal cells

1. Skin cells

2. Muscle cells

3. Blood cells

4. Nerve cells

5. Fat cells

What is a vacuole

It is a fluid-filled sac that stores water and can make up as much as 90% of a plant cell’s volume

What is a chloroplast

They contain chlorophyll which is needed for the process of photosynthesis

What is a cell wall

It surrounds the cell and is made of cellulose and increases the structural strength of the cell

List sub-cellular structures found in a plant cell

• Vacuole

• Chloroplast

• Cell wall

• Cell membrane

• Nucleus

• Ribosomes

• Mitochondria

• Cytoplasm

What is a flagella

It a whip-like structure used for movement and not seen in bacteria

What is a plasmid

It is a small ring of DNA

List sub-cellular structures found in prokaryotic cells

• Ribosomes

• Plasmids

• Cell wall

• Cell membrane

• Cytoplasm

• Flagella

What are gametes

They are reproductive cells

What are the 2 types of gametes

Egg and sperm cells

What are sperm cells

They are type of specialised cell that are found in the male reproductive system

What are the 3 main parts of a sperm cell

The head, middle section and the tail

Describe the features of a sperm cell

• Acrosome: It is located at the tip of the head which contains enzymes needed to penetrate the egg cell

• Head: It contains the sperm cell’s nucleus which carries one half of an organism’s genetic material

• Middle section: It is filled with mitochondria to provide the sperm with the energy it needs to travel a long distance to reach the egg cell

• Tail: It is used for the cell’s motion and allows sperm cells to travel towards the egg cell

How do sperm cells move

They spin their tails in a corkscrew motion

What are egg cells

They are a type of specialised cell found in the female reproductive system