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Flashcards in B2 Part A Deck (46)
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List the 5 main features of an animal cell

  1. Nucleus
  2. Cell membrane
  3. Ribosomes
  4. Cytoplasm
  5. Mitochondria


Which feature of an animal cell is 'selectively permeable'? Define this term 

The cell membrane is selectively permeable, meaning that it allows certain molecules or ions to pass through it by means of active or passive transport.


What are mitochondria?

Sites of aerobic respiration, which allow energy to be released so that the cell can function.


What is the purpose of ribosomes?

Ribosomes connect amino acids onto one another in order to make proteins. They are known as protein synthesizers. 


List the 3 features that are specialist to plant cells and outline what they do

  1. The cell wall (made of cellulose) strengthens and supports the cell.
  2. Permanent vacuoles contain cell sap (a weak solution of salts and sugars which provide energy)
  3. Chloroplasts contain a  green substance called chlorophyll, which is where photosynthesis occurs.


Draw a diagram of a fungal/yeast cell and finish this sentence: Yeast is a ............... microorganism

Yeast is a single-celled microorganism


Draw a bacteria cell (or list the 9 main features)


What is the purpose of the flagellum and which two main types of cell have them?

It enables mobility of both bacteria and sperm cells.


What is the equation for calculating magnification?

Magnification = size of subject in the image ÷ actual size of subject


Which feature of a sperm cell is a cap of enzymes that breaks down the egg wall?

Do sperm cells have mitochondria and a nucleus?

The acrosome is a cap of enzymes that breaks down the egg wall.

Yes, sperm cells have mitrochondria and a haploid nucleus.


Why are red blood cells biconcave and why don't they have a nucleus?

Red blood cells are biconcave because it increases the surface area/volume ratio (bigger surface area). They have no nucleus because this means there is more space for oxygen to attach to the cell.


What form of nucleus does a white blood cell have and why?

It has a lobed nucleus so that it is able to control the whole cell and engulf foreign bodies.


What type of cell is this? Draw a labelled diagram

Root hair cell


What is the purpose of guard cells? Draw a labelled diagram 

Guard cells change shape to control gas and water exchange


What type of cell is this? Label the diagram


What is an egg cells purpose?

To carry the female DNA and nourish a developing embryo in the early stages, for this it contains huge food reserves.


What is a tissue?

A collective of specialised cells that perform the same function


What is an organ?

An organ is various different tissues working together for the same outcome


What is an organ system? Give an example

A series of organs that work in conjunction with one another eg. The digestive system


Name the three different types of tissue in the stomach and outline their purpose

Muscular tissue - contracts and shortens to cause movement that churns up the chyme in the stomach

Glandular tissue - excretes substances which assist with digestion of food in the stomach cavity

Epithelial tissue - covers the inside and outside, acting as a protective lining. Often the cells will be columnar so that other types of cell can embed themselves. 


Label this diagram of the digestive system


What is the purpose of 

  1. Glands (eg. the pancreas and salivary glands)
  2. The stomach
  3. The liver
  4. The small intestine
  5. The large intestine

  1. Glands produce digestive juices
  2. The stomach breaks down and digests food
  3. The liver produces bile
  4. The small intestine absorbs soluble food molecules
  5. The large intestine absorbs water from undigested food, leaving faeces to be excreted from the anus


How does bile aid the digestive system?

The enzymes in the small intestine work best in alkaline conditions, but the food is acidic after being in the stomach. Bile is an alkaline substance stored in the gall bladder. It is secreted into the small intestine, where it emulsifies fats and provides a larger surface area in which the lipases can work.


What plant life process occursin mesophyll tissue?



Give the equation for photosynthesis

Carbon Dioxide + Water ⇒ Glucose and Oxygen


⇒ = sunlight and chlorophyll


Where does photosynthesis occur in plants?

In the chloroplasts


Draw a labelled cross section of a leaf (12 labels in total)


Describe the process of photosynthesis in 4 main steps

  1. Sunlight is absorbed by chlorophyll (in the chloroplasts)
  2. Carbon dioxide diffuses into the leaf and water from the soil reaches cells via the xylem
  3. Using energy from the sunlight, the carbon dioxide and water is converted into glucose in the chloroplasts of the leaf
  4. Oxygen is released as a by-product 


What is the purpose of the waxy cuticle of a leaf?

It stops water from escaping and protects it from insect bites


Name the two different types of mesophyll layer in a leaf and outline their purpose

Palisade mesophyll layer - second layer of cells (below the upper epidermis), because it is towards the surface of the leaf and palisade cells contain chloroplasts, it is the main sit for photosynthesis.

Spongy mesophyll layer - a layer of spongy irregular shaped calles and air space where gas is able to circulate so the plant can absorb it