B2 Retrieval Questions - Year 10 - CS

Process required for growth in animals

Cell division and differentiation in animals

Processes necessary for growth in plants

Cell division, elongation, and differentiation in plants

Stem cells

undifferentiated Cells capable of forming various cell types

Three examples of stem cells

Embryonic stem cells, adult stem cells, meristems

Advantages of embryonic stem cells

Easily extracted, can generate any cell type

Disadvantage of embryonic stem cells

Embryo destruction during cell extraction, can make tumour, moral issues , rejection

Risk with stem cells

Potential uncontrolled division leading to cancer

Advantage of stem cell treatment

Replacement of faulty cells with healthy ones

Advantages of using adult stem cells

No embryo destruction, minimal rejection risk

Disadvantage of adult stem cells

Limited cell type differentiation.

Embryonic stem cells source

Derived from early-stage embryos (8 cells)

Adult stem cells source

Obtained from bone marrow

Meristems location

Located in rapidly growing plant parts like root and shoot tips

Types of neurones in a reflex arc

Sensory, relay, motor neurones

myelin sheath

Part of a neurone that insulates it and speeds up the impulse

dendron

carry impulses towards the cell body

axon

Part of a neurone carrying impulses away from the cell body

Gap between 2 neurones

Synapse

Impulse travel across a synapse

impulse travels to end of neurone . triggers release of neurotransmitters which diffuse across synapse. the neurotransmitters stimulate an electric impulse in second neurone

cell differentiation

process by which cells become specialised

growth percentile charts

used to monitor growth of an organism by comparing its growth to usual trends for that particular organism

reflex arc

stimulus-receptor-sensory-relay-motor-effector-response

what are reflexes

fast, involuntary actions responding to a stimulus - keeps the body safe

What is the cell cycle?

The series of steps that take place as a cell grows and then divides 

steps of the cell cycle

interphase, mitosis, cytokinesis

cytokinesis

the cytoplasm and cell membrane divides to form two identical daughter cells

4 stages of mitosis

prophase , metaphase, anaphase, telophase

prophase

chromosomes condense and nuclear envelope breaks down leaving the chromosomes free in the cytoplasm

metaphase

the chromosomes line up at the centre of the cell

anaphase

spindle fibres split the chromosomes down the centre and pull the chromatids to opposite ends of the cell

telophase

new membranes form around the chromosomes at either end of the cell . these become the nuclei of the two new cells

Which two structures make up the central nervous system (CNS)?

brain and spinal cord

What are the roles of the cerebral cortex?

interpreting senses , memory, consciousness, intelligence and language

What are the roles of the cerebellum?

balance, muscle coordination

role of medulla oblongata

coordinating unconscious activities like breathing rate

hypothalamus

regulates our body temperature

how can scientists study the brain apart from scans

study people with brain damage, electrically stimulate different parts of the brain

why is treatment of the CNS so difficult

some areas are difficult to access ,

its hard to repair damage as neurones don’t readily repair ,

risk of further damage leading to permanent effects

what 2 muscles make up the iris

circular muscles, radial muscles

rod cells

cells that are sensitive to light and more sensitive in dim light

cone cells

cells that are sensitive to different colours

Which two structures refract (bend) light entering the eye? 

cornea, lens

When light passes into the eye, where on the retina should the light be focused?

The fovea

what lens is used to correct long-sightedness

convex

what lens is used to correct short-sightedness

concave

what does a CT scan do

uses X-rays to produce an image of the brain. shows main structures not functions.

what does a PET scan do

use radioactive chemicals to show brain activity. can show both functions and structures in real time

iris

controls how much light enters the pupil

lens

transparent disc that refracts light, focussing it on the retina

cornea

transparent lens that refracts light into eye

retina

where light is detected , has light receptor cells

how do you focus on distant objects

ciliary muscle relaxes but suspensory ligaments pull tight. lens is less rounded so less light is refracted

how do you focus on nearby objects

ciliary muscle contracts but suspensory ligaments slacken. lens is more rounded so more light is refracted

causes of long sightedness

short eyeball or lens not curved enough meaning it doesn’t refract enough light

long sightedness problem

light from near objects is brought to focus behind the retina

causes of short sightedness

long eyeball or lens being too curved meaning it refracts too much light

short sightedness problem

light from distant objects is brought to focus infront of the retina

red-green colour blind problem

red or green cones don’t work

cataracts

cloudy patch on the lens which means less light reaches retina

cure for cataracts

replacing faulty lens with artificial lens

label the brain 1-6

1. cerebral cortex

2. cerebellum

3. spinal cord

4. medulla oblongata

5. pituitary gland

6. hypothalamus

optic nerve

sensory nuerone that carries impulses between the eye and the brain

pupil

hole that allows light to enter the eye

ciliary muscle

a ring of muscle that contracts and relaxes to change the shape of the lens

suspensory ligaments

ligaments that connect the ciliary muscle to the lens

label the eye 1-9

1. suspensory ligaments

2. cornea

3. iris

4. pupil

5. lens

6. ciliary muscles

7. retina

8. fovea

9. optic nerve

label which neurone in which

1. sensory

2. relay

3. motor

2 main parts of human nervous system

Central nervous system , peripheral nervous system

function of sensory neurone

carries impulse from sense organs to CNS

2 features of a processed response and reflex response

processed requires a conscious decision and is slower

why do motor nuerone’s have myelin sheaths

they travel great distance

reflex arc definition

the pathway of a reflex response

growth

permanent increase in size and mass

why is using percentile charts to compare baby growth important

to identify health issues like malnutrition and obesity

what causes uncontrolled cell division

genes that control cell division mutate

similarity and difference of benign and malignant tumours

both form a lump, malignant tumours are cancerous and dangerous as they invade surrounding cells

why in a growing root does only one daughter cell from cell division become differentiated

the other daughter cell stays a meristem for future growth

cell elongation

when hormones such as auxin cause cells to grow longer in response to stimuli like sunlight

how are growth percentile charts used

compares growth of a baby by historical data of children the same age

how is growth measured in babies

mass, height, head circumference

what does it mean if a baby is on the 25th percentile for mass

they are lighter than 75% of children their age but heavier than 25%

why is differentiation important

to allow formation of specialised cells with structural adaptations which allow them to perform specific functions

cell differentiation in plants

meristem can divide and differentiate into any cell type for as long as the plant lives

adult stem cell usage

replace damaged cells or produce new cells for growth

cell differentiation in animal cells

animals lose the ability to differentiate and divide into any cell type after the early stages. only adult stem cells remain

disadvantages of stem cell treatment

tumour development, disease transmission, rejection

adult stem cell usage in medicine

used to replace faulty cells

How are embryonic stem cells used in medicine

They differentiate into cell type . The healthy cells replace the faulty cells .

How can stem cells be used to cure diabetes

The stem cells differentiate into insulin producing pancreatic cells

How can stem cells be used to cure paralysis

Stem cells differentiate into nerve cells to replace damaged neurones

what is the brain made of

billions of interconnected neurones

spinal chord

long column of neurones that run from the base of the brain down to the spine

what does the spinal chord do

relay information between the brain and the body

what 2 types of scans are used to investigate the brain and understand it

CT scans, PET scans

how can a CT scan be used to identify function of an area

if that area is damaged and the patient has lost a particular function - the function of that part can be figured out

what is PET scanner good for studying

disorders that change the brains activity

sensory neurone structure

cell body in the middle. long dendron. short axon

relay neurone structure

small cell body at one end with many short dendrites branching off, axon

motor neurone structure

cell body at one end with long dendrites , an axon and a myelin sheath

adaptations of nuerone’s

myelin sheath, longer axon