5.1 Reproduction
Name two plants that reproduce asexually.
Strawberries - runners
Potatoes - tubers
Daffodils - bulbs
Grapevines - cuttings
Which cell process is responsible for growth and repair of cells?
Mitosis
Which type of cells have circular chromosomes - prokaryotes or eukaryotes?
Prokaryotes
What is homologous chromosome?
A pair of chromosomes with the same genes. One from Mum, the other from Dad.
Name a technology used to determine inheritance patterns in a population.
DNA sequencing or profiling
Distinguish between sexual and asexual reproduction.
Asexual - production of offspring from one parent, genetically identical to the parent.
Sexual - production of offspring from two parents, genetically different to parents.
Name the four stages of mitosis.
P rophase
M etaphase
A naphase
T elophase and C ytokinesis
What is the main source of variation in meiosis?
Crossing over of chromatids.
In terms of DNA sequencing, what is PCR?
Polymerase chain reaction - used to artificially replicate the DNA using enzymes, heating and cooling. It produces many copies.
Name an advantage of external fertilisation in animals.
1. Occurs in water, usually, hence gametes/zygote disperse readily.
2. No parental care is required so that the parent can put energy into the production of large numbers of gametes.
3. Well-suited to aquatic or moist environments.
During which phase do the chromatids move apart (to opposite poles)
Anaphase (anaphase = apart)
What is a polypeptide?
It is a long chain of amino acids, which make up proteins. Peptide bonds join the amino acids together.
A Punnet square is used to predict what?
If a red cow is bred with a white bull, a roan calf is produced (which has red and white hair). What type of inheritance is this?
Co-dominance
Name the male parts of a flower.
Stamen (made up of the anther and filament). The anther produces pollen, which is the male gamete.
During which phase of meiosis does crossing over of chromatids occur?
Prophase
Messenger RNA - carries the genetic code from the DNA in the nucleus to the ribosomes in the cytoplasm.
Transfer RNA - carries a specific amino acid to be joined to the polypeptide chain
Define 'heterozygous allele' and give an example of one in a pea plant.
When the alleles for a trait are different. E.g Tt
What is SNP and what is it used for?
Single-nucleotide polymorphism (variations in one nucleotide base). It is used to identify carriers of disease and to compare genetic variation within/between species.
Name two hormones in mammals and outline the role they play in reproduction.
Progesterone - maintains uterus and lining for nourishment and retention of embryo.
Oestrogen - prepares the uterine muscles for labour.
Oxytocin - causes contractions during birth, and milk let-down when breastfeeding
Relaxin - relaxes muscles, ligaments and tendons during birth.
Name three ways that cell replication ensures the continuity of species.
1. Asexual reproduction depends on mitosis, which replicates cells. E.g. Binary fission in bacteria and fungi, starfish that regenerate from fragments. This expands populations and ensures continuity of species.
2. Sexual reproduction relies on meiosis. Meiosis produces gametes, which combine during fertilisation. Genetic input from 2 parents increases genetic diversity, which contributes to the continuity of species.
Distinguish between the four different levels of protein structure.
Primary - sequence of amino acids held together by peptide bonds
Secondary - amino acids organised into alpha helices or pleated beta sheets
Tertiary - major bends and folds of the polypeptide chain, attractions provide stability
Quaternary - a combination of polypeptide chains to form a protein molecule
How can you tell if a pedigree shows autosomal dominant inheritance?
Males and females are equally affected, and the condition is expressed in every generation.
Give an example of a large-scale collaborative project in conservation management in Australia.
Tasmanian Devil Facial Tumour Disease. The Australian Government and the University of Sydney are collaborating to map the Devil's genome, revealing genetic studies that have identified 20,000 mutations in cancer cells.
Now scientists are investigating whether behavioural adaptations are random and the result of genetic drift, or a result of natural selection.