Paper 1 - cell biology

two examples of eukaryotes

animal cell, plant cell

in eukaryotes, what is genetic information enclosed in

nucleus

compare size of prokaryotic cell vs eukaryotic cell

prokaryotes much smaller

in prokaryotes, what does genetic material consist of

loop of DNA, plasmids

how many micrometres in a meter

1,000,000

how many nanometres in a metre

1,000,000,000

what is the idea of order of magnitude

every order of magnitude is 10x greater than the one before

what is cytoplasm

where chemical reactions take place

what is cell membrane

controls what enters and leaves cell

what is mitochondria

release energy for aerobic respiration

what are ribosomes

site of protein synthesis

what is nucleus

contains genetic material

what are chloroplasts

contain chlorophyll and site of photosynthesis

what is cell wall

made from cellulose, provides structure and support

what is vacuole

filled with cell sap, helps give plant shape

what does it mean if a cell is specialised

has adaptations which help them carry out specific function

what is differentiation

when cells become specialised

what is fertilisation

sperm cell join with ovum

4 adaptations of sperm cell

• long tail to swim to ovum

• streamlined to make swimming easier

• lots of mitochondria to provide energy for swimming

• contain enzymes, allow them to digest their way through outer layer of ovum

what is the job of a nerve cell

to send electrical impulses around the body

what is the role of the axon

carries electrical impulses from one part of the body to another

what is the role/adaptation of myelin

insulates axon, speeds up transmission of nerve impulses

what is the role of synapses

junctions which allow impulses to pass from one nerve cell to another

what is the role/ adaptation of dendrites

increase surface area so other nerve cells can connect more easily

what is the key feature of muscle cells

can contract

what do muscle cells contain which allow them to contract

protein fibres shorten when muscle cell contracts, decreasing length of cell

what do muscle cells have lots of

mitochondria to release energy for muscle contraction

describe how to prepare a slide of a sample of onion cells and view it under a microscope (rp)

1. use a scalpel to cut and remove a thin layer of onion

2. place on a slide and add a stain

3. place a cover slip on top at an angle

4. put the slide on the microscope stage and secure with clips

5. turn on the light

6. view through the eyepiece using the lowest power objective lens

7. use coarse focus to get a clear image

8. increase power of the objective lens and use fine focus to get a clear image

equation linking actual image size, image size, and magnification

actual image = image size/ magnification

what is binary fission

one bacterial cell splits into two bacterial cells

how do bacteria cells multiply

by simple cell division

how often can bacteria carry out binary fission

every 20 minutes

how do you calculate number of bacteria

2 to the power of n (number of rounds of division)