Biology paper 1

role of vacuole

stores sap

cytoplasm

-jelly like substance

-makes up the cell

what is mitochondria the site of

sight of respiration

What do enzymes break down

larger molecules to smaller molecules

enzyme practical

-mix amylase and starch then time

-remove drops to tiled dimple with iodine solution

-record time take for no starch (stays orange)

-repeat at different temps/pH solutions

-draw curved line of best fit

Why does temperature increase the rate of reaction in an enzyme?

molecule energy increases

what does amylase break down starch into

glucose

what colour do sugars change benedict’s solution to

blue to green/yellow to orange to brick red

what colour does proteins turn biuret’s solution

blue to purple

Diffusion

movement of particles or molecules from a high concentration to a low concentration

osmosis

net movement of water across a partially permeable membrane to balance out the solution on the inside and outside of a cell

factors that increase the rate of osmosis and diffusion

-Temp

-Surface Area

-Difference in concentration

osmosis practical

-potato cylinders into test tube of solution with varying sugar concentrations

-after left for a day remove cylinders and dry them

-then reweigh

-calculate % change in mass

does active transport require energy?

yes

active transport

movement of particles across a membrane via carrier proteins

where is DNA stored

chromosomes

how many pairs of chromosomes do humans have

23 pairs(Diploid)

how many chromosomes do gametes have

23 only (Haploid)

what is mitosis used for

growth and repair

what does IPMATC stand for

-interphase

-prophase

-metaphase

-telophase

-cytokinesis

what happens at the interphase?

chromosomes duplicate

what happens at the prophase

nucleus membrane dissolves

what happens are the metaphase

two sets of chromosomes line up in the middle

what happens at the anaphase

chromosomes are pulled to opposing sides of the cell

what happens at the telophase?

-nucleus forms to house copied chromosomes

-forms two identical daughter cells

what is cytokinesis

when the nucleus divides

how is cancer formed?

when damaged cells divided uncontrollably

where are stem cells found?

plant meristem

anima embryos

why are stem cells specialised

to perform specific functions

what type of cell can stem cells in blood marrow become?

blood cells

what are embryo clones used for

treat conditions without rejection

what is plant cloning used for?

prevent extinction of a plant

what does CNS stand for and what makes it up

central nervous system.brain and spinal chord

what does the PNS stand for and what is it made up of

peripheral nervous system. other nerves around the body

what is a synapse

gap between two neurones

what is a receptor

detects change

what is a stimulus

something that makes us react

nervous system practical

ruler drop test

independent variables:depressant and stimulant

How do we react

-receptor detects change (hot stove)

-electrical signal travels to spine by sensory and relay neurones

-signal travels to the synapse via neurotransmitter chemical

-once at spine signal reaches the brain to make the decision to act

-signal goes back to effector to move our arm

what is a reflex

when the receptor detects change and sends a signal to the spine by sensory and relay neurones and neurotransmitter chemicals from the synapse reach the spin bypass the brain and straight to the effector aka your arm

How can we increase the rate of diffusion and osmosis?

increase temp and surface area

where is amylase made

salivary glands and pancreas

what does amylase do

breaks down starch into glucose

what are villi

cells in small intestines

absorb nutrients into blood stream

risk factor for diabetes

poor diet and obesity

risk factors of heart disease

poor diet

lacking exercise

risk factor for liver disease

drinking

risk factor for lung disease

smoking

what is meiosis

the process which gametes are made

stages of my meiosis

1.)chromosomes in diploid are copied

2.)similar chromosomes pair up

3.)cell divides=two diploid cells

4.)doves again into 4 cells

what is DNA

double helix polymer

A&T

C&G

advantage of sexual reproduction

offspring better adapted to environment

advantage of asexual reproduction

only one organism needed to reproduce

how do you clone an animal

take nucleus from one animal into another animal egg

what do lymphocytes do

produce antibodies that bind to virus’ antigen

what do phagocytes do

invest and destroy viruses

How do vaccines work

let’s lymphocytes find the right antibody for the real virus

what is a blind trial

doctors give test group the real thing or a placebo subjects don’t know which is which

what is a double blind trial

the doctors don’t know which is placebo or the real deal =unbiased