BTEC applied science biology unit 1

Describe the function of the cytoplasm

Where all of the chemical reactions occur

Describe the function of the vesicles

Transport materials in and out of the cell

Describe the function lf the nucleolus

Produces ribosomes and RNA

Describe the function of the cell wall

Provides rigidity and structure to the cell

Describe the functions of the chloroplast

Site of photosynthesis as they contain chlorophyll

Describe the function of the plasmodesmata

A channel through the cell wall that allows the transport of materials from one cell to another

Describe the function of the amyoplasts

Stores starch and converts it back to glucose when the plant needs energy

Describe the function of the vacuole

Stores water and chemicals for cell use. Also maintains turgor of the cell

Describe the function of the tonoplasts

Membrane surrounds the vacuole, protects the vacuole, isolates it from harmful substances and controls water flow in and out of the vacuole

Why are gran positive bacteria more susceptible to antibiotics?

Permeable cell wall whereas gram negative bacteria has a semi-permeable cell wall

Describe the adaptations found in a palisade cell

Closely packed together for larger surface area

Many chloroplasts that get pushed to the edge of the cell by the large vacuole to absorb as much sunlight for photosynthesis as possible.

Describe the adaptations of a root hair cell

Root hair shape

Large vacuole to maintain shape

Thin cellulose wall to have a quick and effective rate of diffusion

Explain why root hair cells have an elongated section known as the root hair

Increased surface area fir maximum movement of water into the cell

Explain why root hair cells have a large vacuole

Contains cell sap with low warer potential to ecourage water into the cell

Explain why root hair cells have thin cellulose walls

Encourage movement of water and minerals into the cell

Describe the adaptations of a sperm cell

Undulipodium

Lots if mitochondria

Shaped head containing acrosomes

Haploid nucleus

Explain why a sperm cell has an undulipodium

To allow the sperm to move to the egg

Explain why sperm cells contain large numbers of mitochondria

To produce the large amounts of energy needed for movement

Explain why sperm cells contain acrosomes in the head

To digest the zona pellucida and allow entry into the egg

Explain why sperm cells have a haploid nucleus

Contains half the genetic material

Describe the adaptations of egg cells

Contains a haploid nucleus

Protective outer layer (zona pellucida)

Corona radiata

Explain why egg cells have a haploid nucleus

Contains half the genetic material

Explain why egg cells have a zona pellucida ( protective layer)

Protects the cell and only allows one sperm cell to enter

Explain why egg cells have a corona radiata ( two or three layers attatched to the zona pellucida)

Contains all of the proteins needed to develop the fertilised cell

Decribe the adaptations of red blood cells

No nucleus (mammals only)

Biconcave shape

Haemoglobins

Flexible

Explain why red blood cells don’t contain a nucleus

Allows for more oxygen to be carried in the cell

Explain why red blood cells have a biconcave shape

Increased surface area for gas exchange

Explain why red blood cells contain haemoglobin

To bind with oxygen in order for it to be carried around the body

Explain why red blood cells are flexible

To fit through the tiny blood vessels such as calillaries

Describe the adaptations of white blood cells

Multi-lobed nucleus

Enzymes found within the lysosomes

Explain why whute blood cells have a multi-lobed nucleus

To enable the cell to squeeze through tiny gaps when travelling to the site of infection

Explain why lysosomes found within the cytoplasm of white blood cells enzymes

To digest engulfed pathogens

Name the 3 different types of epithelial tissue

Squamous epithelial tissue

Columnar epithelial tissue

Endothelium tissue

Decribe squamous epithelial tissue

A lining tissue thaf is only only one cell thick. Made from squamous cells that form a smooth, flat layer

Where can squamous epithelial tissue be found

As it is a tissue it can be founf inside alveoli

How can squamous epithelial tissue be damaged by smoking?

Inflammation and scarring of tissue

Tissue gets thicker and produces more mucus

Diffusion pathway is increased

What does COPD stand for?

Chronic Obstruction Pulmonary Disorder

What symptoms can be displayed from COPD

Breathlessness

Persistent coughing

Phlegm build up

What comditions are considered part of COPD

Emphysema

Bronchitis

Asthma

Describe columnar epithelial tissue

Column shaped ciliated cells and goblet cells held in place by a membrane

What is meant by the term ciliated cell

A cell covered in cilia. Cilia are fine hair like projections that sweep away pathogens from the lungs

How does smoking affect ciliated columnar tissue?

The cilia can break, lessening the sweeping action overall. This leads to a build up of mucus

What is the role of the goblet cells

To produce mucus

How do goblet cells and ciliated cells work together

Goblet cells produce mucus that sticks to pathigens, whilst cilia sweep away the mucus containing the pathogens

How does smoking affect the alveoli

Reduces the elasticity so pockets of air form that cannot be expelled

What is atherosclerosis

The process of white blood cells encouraging the deposition of fatty substances (cholesterol) below the endothelial lining

What factors can increase the likelihood of atherosclerosis

Smoking

High blood pressure

How does smoking affect the alveoli?

Reduces the elasticity so pockets of air form that cannot be expelled

Whereis endothelial tissue found?

Lining the inside of blood vessels, lymphatic vessels and the heart

Describe the structure if endothelial tissue

A layer of flattened cells, one layer thick

What comditions can atherosclerosis cause?

Angina

TIA (mini strokes)

Heart attack

Aneurysm and haemorrhage

Name three types of skeletal muscle

Cardiac

Skeletal

Smooth

What type of control is exhibited in skeletal muscle?

Voluntary control

Wgat type of control is exhibited in smooth muscle

Involuntary control

Where can skeletal muscle be found?

Attatched to bones

Where can cardiac muscle be found

In the heart

Where can smooth muscle be found

In the walls of hollow organs such as the stomach and bladder

Put the following in order of size from largest to smallest

Muscle, bundke of fibres, fibre, myofibril, filaments

Muscle fibres are many cells joined together. What organelles do the cells share?

Nuclei and cytoplasm, inside which are many mitochondria and specialised ER

Why do muscle cells contain many mitochondria

To provide large amounts of energy to the muscle for contractions

Give the term used to describe the striby bands seen within skeletal muscle under a microscope

Striations

Myofibril is made up of dark and light bands. What are the names given to these dark and light bands?

Dark band = A band

Light band = I-band

Which line is present in the middle of the A-band?

M line

Which line is present in the middle of the I-band?

Z line

What is the name given to these dark space between two Z-lines?

Sarcomere

Myofibril is made up of alternating thick and thin filaments. What are the names of these?

Thick = myosin filament

Thin = actin filament

What happens to the sarcomere during muscle contraction?

It shortens

What are the two types of skeletal muscle

Fast twitch and slow twitch

Which sports are slow twitch muscle fibres best for?

Long distance running and cycling

Fast twitch muscles can be further divided into two sub catgories. what are they?

fast twitch oxidative muscles and fast glycolytic muscles

which sports are fast twitch oxidative muscle fibres best for?

mid-range sports such as 1500m

which sports are fast twitch glycolytic muscle fibres best for?

sprinting, short burst sports

what type of exercise are slow twitch muscles designed for?

aerobic exercise

what type of exercise are fast twitch muscles designed for?

anaerobic exercise

in which type of muscle fibre is the speed of contraction slowest

slow twitch

in which type of muscle fibre is the speed of contraction highest?

fast glycolic twitch

describe the characteristics of slow twitch muscle fibres

less sarcoplasmic reticukum (specialised ER)

more mitochondria

more myoglobin

a dense capillary network

describe the charaxteristics of fast oxidative muscle fibres

similar to slow twitch with many mitochondria, myoglobin and capillaries

hydrolyse ATP faster to contract more quickly

describe the characteristics of fast glycolytic twitch muscle fibres

less myoglobin

large concentration of glycogen for anaerobic respiration

what structures make up the nervous system?

brain, spinal cord, nerves

what is the scientific name for nerve cells?

neurones

name the organelles of the neurone

dendrite, cytoplasm, nucleus, soma, axon, myelin sheath, axon terminal, schwann cell, node of ranvier

what parts of the nervous system make up the central nervous system?

brain and spinal cord

which parts of the nervous system make up the peripheral nervous system?

neurones

define the term ‘synapse’

the small gap in between the axon terminal of one neurone and the dendrite of the next neurone

define the trrm ‘action potential’

the impulse passed along the axon

define the term ‘resting potential’

when the neurone is not transmitting an action potential. durung this time the K+/Na+ is at work

what are the 5 sensory receptors?

touch, taste, smell, hearing, sight

describe the myelin sheath

a thick insulating layer around the axon

describe the dendrites

highly branched fibres that conduct impulses

describe the axon

a long single fibre that carries nerve impulses

describe the schwann cell

a cell wrapped around the axon, forming the myelin sheath

describe the nodes of ranvier

gap in the myelin sheath where the axon is exposed

describe the differences between myelinated and non-myelinated cells

myelinated cells are longer and can transmit impulses faster down the axon

why do myelinated neurines transmit action potentials quicker than non-myelinated

insulated myelin sheath

impulse ‘jumps’ from node to node (where the sodium gates are located)