IGCSE Edexcel Biology - 1.1 Living characteristics of Organisms

What is the defining structural feature shared by all eukaryotic cells?

They contain a nucleus surrounded by a distinct membrane.

Name the four kingdoms that make up the eukaryotic organisms.

Plants, Animals, Fungi, and Protoctists.

Which group of organisms is characterized by the absence of a nucleus?

Prokaryotes (Bacteria).

How is genetic material stored in a prokaryotic cell?

As a single, circular chromosome of DNA found in the cytoplasm.

In addition to a main chromosome, prokaryotes may contain small extra circles of DNA called _____.

Plasmids

What material makes up the cell walls of plants?

Cellulose

Which organelles are present in plant cells to allow for photosynthesis?

Chloroplasts

In what two forms do plants typically store carbohydrates?

Starch or sucrose.

Give an example of a cereal plant mentioned in the specification.

$\textit{Maize}$

Give an example of a herbaceous legume.

Peas (or beans).

True or False: Animals have cell walls to provide structure.

False (animals lack cell walls).

How do animal cells typically store carbohydrates?

Glycogen

Which feature allows animals to respond rapidly to stimuli in their environment?

Nervous coordination.

Give an example of an insect from the animal kingdom.

Housefly (or mosquito).

Name the material that forms the cell walls of fungi.

Chitin

The body of a multicellular fungus is organized into a network called a _____.

Mycelium

What are the thread-like structures that make up a fungal mycelium?

Hyphae

Fungal hyphae are unique because they often contain many _____.

Nuclei

Which method of nutrition involves the extracellular secretion of enzymes onto food material?

Saprotrophic nutrition.

How do fungi store carbohydrates?

Glycogen

Give an example of a multicellular, hyphal fungus.

$\textit{Mucor}$ (bread mould).

Name a single-celled example of a fungus.

Yeast

Why are protoctists sometimes described as the 'dustbin kingdom'?

They are a diverse group that does not fit into the other eukaryotic kingdoms.

Which protoctist is considered animal-like and lives in pond water?

$\textit{Amoeba}$

Name a plant-like protoctist that contains chloroplasts.

$\textit{Chlorella}$

Which pathogenic protoctist is responsible for causing malaria?

$\textit{Plasmodium}$

What is the general term for an organism that causes disease?

Pathogen

Which bacterium is used in the production of yogurt?

$\textit{Lactobacillus bulgaricus}$

Name the pathogenic bacterium that causes pneumonia.

$\textit{Pneumococcus}$

How does the size of a prokaryotic cell compare to a eukaryotic cell?

Prokaryotic cells are substantially smaller.

Which eukaryotic kingdom is always multicellular and lacks cell walls?

Animals

Which eukaryotic kingdom is always multicellular and possesses cellulose cell walls?

Plants

Identify the storage carbohydrate shared by both animals and fungi.

Glycogen

Are viruses classified as prokaryotic or eukaryotic cells?

Neither (they are non-cellular pathogens).

Give an example of a common virus.

Influenza (or HIV).

Which eukaryotic group is mostly microscopic and single-celled?

Protoctists

Concept: Saprotrophic Nutrition

Definition: Feeding by secreting digestive enzymes outside the body and absorbing the digested products.

Mnemonic: Which two kingdoms store Glycogen?

Animals and Fungi (A and F come before G in the alphabet).

Where are the circular DNA chromosomes located in bacteria?

In the cytoplasm.

Plants are referred to as _____ because they produce their own food.

Autotrophs

Animals are referred to as _____ because they feed on organic substances made by others.

Heterotrophs

Do plants possess nervous coordination?

No.

Which kingdom's cell walls are composed of cellulose?

Plants

Which kingdom includes organisms that can aggregate into colonies but are primarily single-celled?

Protoctists

What material allows animal cells to be flexible and move from place to place?

The lack of a rigid cell wall.

Which specific protoctist has features more like an animal cell?

$\textit{Amoeba}$ (or $\textit{Plasmodium}$).

Which specific protoctist has features more like a plant cell?

$\textit{Chlorella}$

Bacteria are always _____-celled.

Single

In saprotrophic nutrition, absorption occurs *after* _____ digestion.

Extracellular

Which eukaryotic kingdom does NOT contain chloroplasts but can be multicellular?

Fungi (or Animals).

True or False: All fungi are multicellular.

False (some, like yeast, are single-celled).

What is the primary mode of nutrition for the Plant kingdom?

Photosynthesis

Which kingdom is unique for having hyphae that form a mycelium?

Fungi

What is the storage carbohydrate in a housefly?

Glycogen

What is the storage carbohydrate in bread mould?

Glycogen

What is the storage carbohydrate in maize?

Starch or sucrose.

Which eukaryotic group is described as being 'usually larger and more complex' than prokaryotes?

Eukaryotes

Name a pathogenic fungus mentioned in the notes.

Athlete's foot.

In a bacterial cell, the single circular chromosome is the _____ material.

Genetic

Which group of organisms are *always* pathogenic?

Viruses