Reproduction and Inheritance Flashcards
What is DNA?
A long list of instructions on how to put an organism together and make it work.
What is a genome?
The entirety of the DNA in an organism.
What does each separate gene do in a DNA molecule?
A chemical instruction that codes for a particular protein.
How do genes control our inherited characteristics?
They control the production of proteins, meaning they control our inherited characteristics.
What are alleles?
Different versions of the same gene.
Define Asexual Reproduction:
Reproduction involving only one parent, where the offspring are genetically identical to the parent.
Define Mitosis:
When a cell reproduces itself by splitting to form two cells with identical sets of chromosomes.
What is mitosis used for?
Growth and repair of damaged tissues in plants and animals Asexual Reproduction (non-human)
Define Sexual Reproduction:
the fusion of male and female sex gametes. The offspring are a mixture of the parent’s genes.
What is produced through meiosis?
Meiosis produces four haploid cells whose chromosomes are not identical.
What cells are created through mitosis?
Two diploid cells are created from a single diploid cell.
What are the human gametes?
Sperm cell - Men
Egg cell - Women
In humans, were are the only places that meiosis occurs?
In the reproductive organs - Ovaries and the Testes.
What is the male and female gamete part for a plant?
The Stamen is the Male
The Carpel is the Female
What is pollination?
The transfer of pollen from an anther to a stigma, so that the male gamete can fertilise the female gamete.
What are the two parts of the stamen?
Anther and Filament
Anther contains pollen grains which produce the male gamete.
Filament is the stalk that supports the anther
What are the three parts of the Carpel
The Ovary, Style and Stigma
The ovary contains the female gametes inside ovules.
The style is the rod-like section that supports the stigma.
The stigma is the end bit which the pollen grains attach to.
How are plants adapted for wind pollination?
- Small, dull petals
- No scents
- Many small, light pollen grains to be carried eaily by the wind.
- Long filaments that hang outside the flower to ensure pollen gets blown away.
- Large, feathery stigma to catch pollen floating in the wind.
How are plants adapted for insect pollination?
- Bright coloured petals to attract the insects
- Scented flowers and nectaries to attract insects
- Big, sticky pollen grains that stick to insects as they go from plant to plant.
- Stigma is also sticky so that any pollen will stick to the stigma.
Where is the pollen tube grown?
From the stigma, through the style, into the ovary
Give an example of a plant that reproduces asexually:
Strawberry’s
What are runners?
Fast-growing thin stems that grow out sideways, just above the ground. They plant new seeds for reproduction asexually.
What happens to a plant when it is fertilized in the ovary?
The fertalised egg forms a seed. The ovary develops a fruit around the seed
What transforms the zygote into an embryo? (plants and humans)
Mitosis cell divisions
What causes a seed to lie dormant?
A seed may lie dormant until the conditions are right for germination.
What conditions are required for germination of seeds?
- Water, to activate enzymes that break down the food reserves.
- Oxygen, fro respiration which produces energy for growth.
- Temperature, varies between seeds.
How many different amino acids are there in humans?
20
What determines the shape of a protein?
The specific order of amino acids
State a protein for each use
1 - Enzyme
2 - Structural
3 - Hormone
Enzyme Protein = Amylase
Structural Protein = Collagen
Hormone Protein = Insulin
What determines the order of amino acids?
The sequence of bases in the gene for that protein.
What is a triplet?
three bases lined up
What does each triplet of bases code for?
a specific amino acid.
Where does transcription happen?
Nucleus
What does mRNA stand for?
Messenger RNA
Is mRNA single or double stranded?
Single Stranded
What happens during transcription?
The base sequence of the gene is copied into a complementary template molecule
What are the bases used in mRNA?
Adenine
Cytosine
Guanine
Uracil instead of Thymine
Where are proteins made?
By Ribosomes.
Where does translation occur?
In the cytoplasm
What is tRNA?
Translation RNA
