Unit 2

Question 1

What is an organelle?

Answer 1

An organelle means ‘little organ’, organelles are the organs of cells.

Question 2

What is the nucleus?

Answer 2

The nucleus of the cell is the control centre of the cell and it contains the genetic code of the cell in the form of DNA. The nucleus provides ribosomal RNA (where the ribosomes come from)

Question 3

What are ribosomes?

Answer 3

It is the site of protein synthesis. Ribosomes link amino acids together to make protein. They can also use DNA, RNA and various enzymes.

Question 4

What is the cell/plasma membrane?

Answer 4

The plasma membrane serves to keep internal and external environments separate. They are semi-permeable and thing.

Question 5

What is a chloroplast?

Answer 5

A chloroplast is an organelle that converts light energy into chemical energy. It is the site of photosynthesis and it gives plants their green colour.

Question 6

What is the mitochondria?

Answer 6

The mitochondria is the site of cellular respiration, it is what converts glucose from nutrients into a form of energy (ATP) that can be used.

Question 7

What is ATP?

Answer 7

ATP stands for adenosine triphosphate. It’s a form of energy.

Question 8

What is a cell wall?

Answer 8

A cell wall is structural layer that surrounds usually plant cells and it can be found immediately outside the cell membrane. Primarily, it provides the cell with structural support, shape, protection, and functions as a selective barrier.

Question 9

What is a vacuole?

Answer 9

A vacuole is the organelle responsible for the storage of compounds and excretion of waste products from respiration.

Question 10

How does the size of the vacuole differ between animal and plant cells? And why?

Answer 10

Animal cells have many small or absent vacuoles while plant cells only have a singular large one that occupies approximately 90% of the cell volume. This is because plants require more nutrients and water, therefore a larger vacuole to store. Vacuoles also maintain turgidity which is a cellular phenomenon of cell swelling because of the absorption of high fluid content. The vacuole also pushes out chloroplasts for more light exposure in plant cells.

Question 11

What are lysosomes?

Answer 11

Lysosomes are sacs containing enzymes that can break down parts of a cell.

Question 12

What function do smooth and rough endoplasmic reticulum have?

Answer 12

Smooth ER have no ribosomes and create lipids while rough ER have ribosomes and makes secretory proteins.

Question 13

What is the Golgi apparatus?

Answer 13

Responsible for the transporting, sorting, and modifying of proteins and lipids.

Question 14

What is a cytoplasm?

Answer 14

A cytoplasm is made of two parts, organelles and cytosol (the gelatinous liquid that fills the inside of the cell so everything within the cell membrane excluding organelles).

Question 15

Describe bacterial structure.

Answer 15

A bacteria cell is composed of a cell wall made of peptidoglycan, cell membrane, cytoplasm, ribosomes, and a plasmid instead of a nucleus.

Question 16

What is plasmid?

Answer 16

Plasmid is a circular piece of DNA carrying genes/traits that can be exchanged between bacteria.

Question 17

What are 6 specialised cells?

Answer 17

The red blood cell, ciliated cell, nerve cell (neurons), root hair cells, palisade mesophyll cell, and sperm cell.

Question 18

State red blood cell functions and properties.

Answer 18

Red blood cells carry oxygen into the blood. they have a biconcave shape that allows them a higher surface area which in turn aids in increasing the rate of oxygen diffusion. This allows the red blood cells to fit through capillaries. Red blood cells contain a lot of hemoglobin (a protein that binds oxygen) and also no organelles to maximise space for hemoglobins.

Question 19

State the functions and properties of a ciliated cell.

Answer 19

Cilia is a specialised organelle that helps move mucus through airways and it can be found in the lungs.

Question 20

State the functions and properties of a root hair cell.

Answer 20

Root hair cells have finger-like projections that stick out from the cell that increases the surface area which allows for faster osmosis and diffusion of minerals to the plant.

Question 21

State the functions and properties of a palisade mesophyll cell.

Answer 21

Palisade mesophyll cells contain a lot of chloroplasts which affects the potential rate of photosynthesis. They also have thin cell walls to allow for more light exposure and it can be found in the top section of the leaf.

Question 22

State the functions and properties of a nerve cell (neurons).

Answer 22

Neurons send signals between nerves at a relatively slow rate but they’re long to increase the speed in which the signals travel.

Question 23

State the functions and properties of a sperm cell.

Answer 23

Sperm cells have a flagella to help them swim from the vagina to the fallopian tube and they have heads shaped in a way to optimise egg penetration.

Question 24

Describe a cell.

Answer 24

A cell is the smallest organism or unit that is capable of living independently.

Question 25

Describe a tissue.

Answer 25

A tissue is a group of cells with a similar structure and function.

Question 26

Describe an organ.

Answer 26

An organ is a group of different tissues with related functions.

Question 27

Describe an organ system.

Answer 27

An organ system is a group of related functions.

Question 28

What is the triangle formula for magnification?

Answer 28

I, A, M. Image size over actual size and magnification.

Question 29

How do you convert mm to μm?

Answer 29

Multiply the mm by 1000 to get the μm and divide μm by 1000 to convert it to mm.