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Description
| Question | Answer |
| •survival advantage •mate •extinct •parent •desirable characteristics •natural selection •variations •identical •selective breeding | |
| ____ involves the fusion of a male and female gamete to produce a ____ that undergoes cell division and developed into an ____ | fertilisation zygote embryo |
| What is GERMINATION | the process in which seeds begin to develop into a new young plant |
| What are the three elements needed to facilitate germination and why | Water: to activate enzymes to break down the starch food reserves in the seeds Oxygen: for aerobic respiration to release energy for growth Warmth: optimum temp for enzymes will increase growth rate |
| Secondary sexual characteristics Females: oestrogen Name 5 symptoms of oestrogen present in a female | Breast development Menstrual cycle begins Growth of body hair Widening of hips Increased height |
| Secondary sexual characteristics Male: testosterone Name 5 symptoms of testosterone present in a male | Growth of penis and testes Production of sperm Growth of facial and body hair Muscle development Voice lowering and breaking |
| Menstrual cycle The menstrual cycle lasts ____ days and the egg is usually released on day ____ (ovulation) | 28 14 |
| Developing embryo The placenta allows diffusion of ___, ___ and ___ ___ from the mother's blood to the developing foetus of growth. ___ ___ and ___ from the foetus are passed into the mother's blood to be removed. It also takes one the production of ___ | glucose oxygen amino acids carbon dioxide urea progesterone |
| What am I describing? An organism's reproductive cell (egg in female and sperm in males), which has half the number of chromosomes (23) | Gamete |
| What am I describing? The entire DNA of an organism | genome |
| A structure found in the nucleus which is made up of a long strand of DNA | Chromosome |
| Gene | |
| The different forms of the gene - humans have two alleles for each gene as they inherit one from each parent | Allele/variant |
| Only one (out of two alleles) is needed for it to be expressed and for the corresponding phenotype to be observed | Dominant allele |
| Two copies are needed for it to be expressed and for the corresponding the phenotype to be observed | recessive allele |
| When both inherited alleles are the same (ie two dominant alleles or two recessive alleles) | Homozygous |
| When one of the inherited alleles is dominant and the other is recessive | Heterozygous |
| The combination of alleles an individual has eg Aa | Genotype |
| The physical characteristics that are observed in the individual eg eye colour. Phenotypic features are the result of polygenic (multiple genes) inheritance rather than single genes | Phenotype |
| When neither allele is dominant over the other, so both contribute to the phenotype eg. a white chicken and black chicken can have offspring that are speckled so the web is codominant | Codominance |
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