B5

HideShow resource information
what are cells like in organisms that are multicellular
not specialised, so they can do different jobs
1 of 56
how are similar cells grouped
into tissues, an example is muscle tissue
2 of 56
what happens in organs
different tissues are grouped together and work together
3 of 56
what is a fertilised egg called
a zygote
4 of 56
how does an embryo form
by the zygote dividing by mitosis
5 of 56
what is differentiation
cells developing into specialised cells after being embryonic stem cells
6 of 56
when are the cells identical in humans
up to and including the 8 cell stage, when they are still embryonic stem cells
7 of 56
what happens to specialised plant cells
they form tissues
8 of 56
in a plant, how are tissues organised
into organs. eg stems, leaves, roots
9 of 56
what is a meristem
an area of a plant where the cells are not specialised. such as the top of the shoot
10 of 56
in plants, what are the only cells that can divide
meristems
11 of 56
what happens when a meristem divides into two
the new cell that's produced can differentiate into different cell types. the other cell stays as a meristem
12 of 56
what do meristems in plants do
produce growth in height and width due to division
13 of 56
what is a cutting
pieces of a plant, that have meristems and are used to form clones
14 of 56
what are cuttings used for
to make genetically identical plants called clones OR ti make new plants with the same features
15 of 56
how is root growth in cuttings encouraged
plant hormones, using hormone rooting powder
16 of 56
what is tissue culture
another way of plant cloning
17 of 56
how does tissue culture work
cells are taken from a plant room or stem > enzymes are used to split them apart > each cell is placed on nutrient jelly to grow into plantlets > the plantlets are then planted to form genetically identical
18 of 56
what are auxins
plant hormones that are in rooting powder, and the jelly that is used in tissue culture
19 of 56
what do auxins do
increase cell division and cell enlargement, encouraging growth of plant tissue
20 of 56
what is the name of a plants response to the direction of sunlight
phototropism
21 of 56
why are plants described as 'positively phototropic'
they grow towards the sunlight
22 of 56
why does growing towards the light, essential for plant survival
light is essential for photo synthesis
23 of 56
where is auxin produced
in the growing tip of plant shoots
24 of 56
what happens if a plant is illuminated from one side
auxin in the tip is distributed towards the shaded side > auxin produces growth on the shaded side > shoot grows towards the light
25 of 56
what is Mitosis
the type of cell division that happens when an organism grows, and cells divide to repair tissues
26 of 56
what is produced in mitosis
two daughter cells that are genetically identical
27 of 56
what happens before and during mitosis
before mitosis, the DNA in each chromosome is copied. each chromosome is now a double chromosome with two DNA molecules. during mitosis, each chromosome separates so two nuclei and two cells are produced.
28 of 56
the events leading up to and between cell division, and cell division itself, are called what
the cell cycle
29 of 56
what are the main processes of the cell cycle
cell growth and mitosis
30 of 56
if the cell size increases, what also increases
the number of organelles
31 of 56
what is Meiosis
the type of cell division used to produce gametes
32 of 56
what are gametes
sex cells
33 of 56
describe gametes in humans
they have half the amount of chromosomes as body cells
34 of 56
what happens in fertilisation
gametes join to make a zygote
35 of 56
why is it important that gametes contain 23 chromosomes
because they join to make zygotes and zygotes have 46 in total
36 of 56
what are the main differences between Mitosis and Meiosis
Mitosis produces two genetically identical daughter cells that have the same number of chromosomes as the parent cell. Meiosis produces four gametes (eggs or sperms) that have half the number of chromosomes from the parent cell
37 of 56
where are chromosomes found
in the nucleus
38 of 56
what is a double helix
the structure of dna
39 of 56
what are bases
bases are chemicals in dna. there are four. A T C and G. they are paired up as AT and CG.
40 of 56
what do the order of bases make up
the genetic code, which instructs the body to make protiens
41 of 56
what is protein synthesis
it is where the amino acids code for making proteins in the body
42 of 56
where does protein synthesis happen
in the cytoplasm
43 of 56
what is messenger RNA
a copy/template of dna, made in the nucleus. It carries the instructions to make proteins. mRNA is needed because genes (which contain dna) do not leave the nucleus
44 of 56
where are proteins assembled
on organelles, in the cytoplasm called ribosomes
45 of 56
what determines the properties and type of protein that is made
the number and sequence of amino acids
46 of 56
what determines the sequence of amino acids
the genetic code
47 of 56
what is tRNA
transfer RNAs,which take the amino acids to the ribosome
48 of 56
how does the cell determine what proteins to use
the cell only produces the proteins it needs to carry out it's particular function. genes needed to make these proteins are switched on, the other genes are switched off.
49 of 56
when are cells identical
when they are embryonic stem cells, up until the 8-cell stage
50 of 56
how do embryonic stem cells and adult stem cells have potential to replace damaged cells
because any gene can be switched on and make any type of cell
51 of 56
what are stem cells used for
to produce new cells to replace damaged or diseased cells
52 of 56
why does using embryonic stem cells raise ethical questions
because when removing cells, the embryo is destroyed. this is controversial as people believe embryos have a right to life.
53 of 56
when are embryonic stem cells removed
usually from surplus embryos during IVF
54 of 56
what is therapeutic cloning
replacing the nucleus of an egg with a nucleus of a body cell, stimulating the egg to divide to produce an embryo
55 of 56
how can inactive genes in nuclei of body cells be reactivated
chemical treatments where scientists form stem cells from mammalian body cells.
56 of 56

Other cards in this set

Card 2

Front

how are similar cells grouped

Back

into tissues, an example is muscle tissue

Card 3

Front

what happens in organs

Back

Preview of the front of card 3

Card 4

Front

what is a fertilised egg called

Back

Preview of the front of card 4

Card 5

Front

how does an embryo form

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all B5 resources »