Jiho bio for Reproduction in Plants and Reproduction in Humans

The basic unit of a DNA is ..

nuecleotide

DNA is?

Deoxyribose sugar, double helix strucutre of two anti parallel polynuceotides, contains genetic information for cell division and cell differentiation

A nucleotide has

Deoxyribose sugar, phosphate group, nitrogenous base

Complementary base are held together by

hydrogen bonds

A gene is a small segment of DNA that codes for the synthesis of ..

polypeptide + one polypeptide = one trait… and it is also a unit of inheritance on a particular locus of a chromosome

Protein synthesis is 2 process which are

transcription and translation

Transcription is.

the production of mRnA using DNA as template

Translation is ..

production of polypeptide using mRNA as template

Transcription comes before translation

OKI

Template strand inside the DNA is used to synthesise

messenger RNA

new mRNA is strand is syntehsised on DNA templpate and is carried to the cytoplasm

OKI

mRNA is read by the.

ribosome

ribosome reads in

codons ( 3 nueclotides) == 1 codon is 1 amino acid

procedures to make insulin gene

isolate gene of interest
- a restriction enzymes cuts the restriciton site sof the gene
sticky ends are produced
the plasmid is cut with the same restricion enzyme
stick ends rpoduced are complementary to those of the insulin gene
the insulin gene and the cut bind by complementary base pariign between their sticky ends
the dna ligase seals the gene to the plasmid
A recombinant plasmid is formed
the recombinant plasmid enters the e coli bacterium with electric shock
the human insulin is extracted

Define asexual reproduction

Production of genetically identical offspring from one parent without the fusion of gametes

Sexual reproduction is

involves the fusion of two nuecli to form a zygote, it produces genetically dissimilar offspring

fertilisation is

fusion of male and female gamete to form a zygote

ovum is

the stuff inside the ovule, and it is the female gamete

ovary is

the stuff outisde

ovule

contains the ovum ( egg)

pollination is

transfer of pollen grains from the anther to the stigma by wind or insect

pollination is important because

it allows male and female to come together for fertilisation

compare self pollination ***

advantages of self pollination
only one parent is requires
ALL beneficial qualities are passed down from parent
Not dependent on external factors for pollination hence it is faster/ more likely to take place and more enrgy efficient

Harms of self pollinatioN
No genetic variation,
less resistant to disease and sudden changes in the environment

compare cross pollination ***

offspring can inherit beneficial qualities from both parents
More genetic variation
Seeds survive longer before germination

two diff species of plants are required
dependent on external factors
less likely to occur and more energy wasted

features of plants

pendulous stamen

fertilisation in plants***

-After pollination pollen grains germinates in response to sugary fluid secreted by mature stigma
-A pollen tube grows out from the pollen grain
-Pollen tube secrets enzymes digest the surrounding tissue of stigma and style
- Pollen tube enters the ovule ( e for egg storage) through the micropyle
-Generative nucleus divides into two male gametes
- Pollen tube nucleus disintegrates
- Pollen tube reaches the ovule and bursts releasing two male gametes
- One male gamete fuses with the ovum, to form zygote.
- Zygote divides and develops into the embryo
- After fertilisation the following changes take place
- Ovule develops into a seed
- Ovary develops into the fruit
- Zygote develops into an embryo