Biology Paper 1

What are all the cell structures and organelles found in an animal cell

Nucleus, cytoplasm, cell membrane, mitochondria and ribosomes

What are all the cell structures and organelles found in a plant cell

all animal structures plus a cell wall, chloroplasts, and a permanent vacuole

What are all the cell structures and organelles found in a bacterial cell

cell wall (not made of cellulose), circular loop of DNA and plasmids

What is each organelles function

Nucleus-stores cell’s genetic material

Ribosomes-synthesis proteins

Mitochondria-generate most of the cells energy supply (ATP) through cellular respiration

Chloroplasts-perform photosynthesis

Cell wall-provides structural support to the cell

Cell membrane-controls the movement of substances in and out of the cell

What are the limitations of a light microscope

maximum magnification is around 1500x and the resolution is limited

What are the advantages of an electron microscope

it allows for much more detailed understanding of sub-cellular structures compared to light microscopes

what is the magnification equation

magnification=image size/real size

What are the stages of mitosis

1-the chromosomes line up and are pulled to opposite sides of the cell

2-each chromosome structure is replicated

3(cytokinesis)-the cytoplasm and cell membrane divide forming 2 genetically identical daughter cells

How are haploid and diploid cells produced

Haploid:mitosis

Diploid:meosis produces 4 non identical haploid gametes

What is key about cell division

growth or repair of cell tissues

What do stem cells do

they divide through mitosis to produce new cells which can then differentiate into specialised cells

What is diffusion

the movement of substances from a high concentration to a low concentration across a partially permeable membrane

What is osmosis

The movement of water molecules across a partially permeable membrane from a low concentration to a high concentration gradient (against the concentration gradient)

What is active transport

the movement of substances against a concentration gradient so low to high

What are all the levels of organisation and their definitions

Organelle-a specialised unit within a cell, such as mitochondrion

Cell-the basic building blocks of all living organisms

Tissue-a group of cells working together to perform a shared function

Organ-a structure made up of different tissues working together for a specific function

Organ system-a group of organs working together

Organism-a complete living being made of multiple organ systems

What is the function of the roots, stem, leaves and transport tissues

Roots-absorb water and minerals from the soil

Stems-support the plant, transport substances and hold leaves up to the light

Leaves-main organ for photosynthesis, gas exchange and transpiration

Xylem-transport water and mineral ions from the roots up the rest of the plants (transpiration)

Phloem-transports sugars and amino acids from leaves to where they are needed for growth and storage (translocation)

what’s the difference between a communicable disease and non communicable disease

a non communicable disease cannot be spread person to person where as communicable can

What is a pathogen and how do they cause damage

A microorganism like bacteria, viruses, fungi, and protists that cause damage to cells

bacteria can damage cells by releasing toxins, while viruses reproduce inside cells causing them to be damaged or destroyed

What are all the key examples of pathogens

Measles, salmonella, HIV, tobacco mosaic virus, and rose black spot

What are the specific and non specific defenses of the body

non specific defenses are the body’s intial layers of protection including the skin, nose, trachea and stomach acid

specific defenses is when something like the immune system uses white blood cells to fight specific pathogens

What is the body’s immune response

Phagocytosis:white blood cells engulf and destroy pathogens

Antibodies:white blood cells produce antibodies that bind to specific pathogens, marking them for destruction

Antitoxins:white blood cells produce antitoxins to neutralise toxins produced by pathogens

How to prevent disease

use hygiene effectively like washing hands and isolation yourself from other people, you could also destroy any organisms which carry said pathogens

How to treat disease

Antibodies:some bacterial infections can be treated with antibiotics, but antibiotic resistance is a thing

Antivirals:viruses can be treated with antibiotics and require specific antiviral medication

How are disease vaccinated against

introduce a weakened or dead pathogen to stimulate an immune response to create antibodies and memory cells for that antigen

explain monoclonal antibodies

identical copies of a single type of antibody that can be produced and can be used for diagnostic and therapeutic purposes, such as targeting specific cancer cells

What are b-lymphocytes

they produce specific antibodies to lock onto antigens on the surface of pathogens, or produce antitoxins to neautralise toxins released by pathogens

What is the process of drug development

Preclinical trials:drug testing done in a laboratory using cells, tissues, and live animals

Clinical trials:test the drug’s effectiveness, dosage and the toxicity on humans

Placebo:an inactive substance used in clinal trials to prevent bias

What is photosnythesis

Plants use light energy to convert carbon dioxide and water into glucose and oxygen (takes place in the chloroplasts)

What are some limiting factors of photosynthesis

light intensity, temperature and co carbon dioxide concentration

What are the temperature effects of photosynthesis

a low temperature level reduces the rate of collisions while very high temperatures cause enzymes to denature

what is the definition of both aerobic and anaerobic respiration

aerobic:a reaction that requires oxygen to break down glucose and release large amounts of energy (occurs in the mitochondria of cells)

anaerobic:a reaction that does not require oxygen to break down glucose (occurs in cytoplasm)

what is the word equation for aerobic respiration

glucose+oxygen→carbon dioxide+water+energy

what is the word equation for anaerobic respiration

Animals:glucose→lactic acid+enery

Plants and yeast:glucose→ethanol+carbon dioxide+energy

why is each type of respiration significant

aerobic:provides energy for all living processes such as muscle contraction

anaerobic(animals):important for short, intense bursts of activity when oxygen supply is limited

anaerobic(plants or yeast):used in fermentation

What are the key metabolism processes

synthesis:building larger molecules from smaller ones

carbohydrates:glucose molecules are joined to form starch, glycogen or cellulose

proteins:glucose and nitrate ions are used to make amino acids which then form to proteins

lipids:fatty acids and glycerol molecules join to form lipids

how is metabolism controlled by enzymes

they are biological catalysts which speed up the rate of reactions so the more you have the faster your metabolism

what’s the difference betweeen metabolism and digestion

digestion involves the breakdown of large, insoluble food molecules into smaller, soluble ones in the gut so they can be absorbed. Metabolism uses these absorbed molecules and carries out further synthesis and breakdown reactions within the body's cells. 

What is transpiration

it is the uptake of mineral ions from the root, it also transports water up the cell which is then evaporated

What is translocation

The movement of sugars and hormones from the leaf down to the roots

2 reasons and explanations for stunted growth in plants

What are the plant materials made in medicine

Explain the role of the liver

The liver stores glucose as glycogen once insulin is released

Explain the role of the pancreas

if blood glucose is too high insulin is released, so glucose moves from blood into cells and any excess glucose is converted to glycogen in the liver

If blood glucose is too low the pancreas releases glucagon, so glycogen is converted back to glucose and released into the blood

Explain the role of the small intestine and large intestine